Evolution of The Beetles [Archive] - Page 6

ericmurphy

March 25th 2011, 01:56 PM

Here's another diagram for Magellan to puzzle over:

http://www.planet-deepblu.com/~eric/graphic_links/SpeciesCurve.png

In this graph, the X axis is the amount of interfertility each population has relative to the other population (not within each population; that number remains close to 100% because selective pressures remove members with reduced fertility, by definition—can you see why, Magellan?).

The Y axis represents time. Over time, interfertility declines.

In the green region, interfertility is close to 100%: the probability of a mating between A and B producing viable offspring is very high (even though no members of A actually are interbreeding with any members of B, due to geographic isolation).

In the brown region, interfertility is close to zero; the probability of a mating between A and B producing viable offspring is very low (even though no members of A actually are interbreeding with any members of B, due to geographic isolation).

In the orange region, the probability of a mating between A and B producing viable offspring takes an intermediate value; some matings would, if they were happening, produce viable offspring, and some wouldn't. At the rightmost edge of the orange region, we might note (if we were to bring members of A and B together to observe levels of interfertility) that litter sizes are smaller, or that most offspring are sterile, or that many have congenital deformities that mean offspring typically don't reach sexual maturity.

In the green region, we can say with a high degree of confidence that A and B are both the same species (as I have defined the term "species" for the purposes of my model). In the brown region, we can say with a high degree of confidence that A and B are different species.

In the orange region, we can say with reasonable confidence that A and B are subpopulations descended from an ancestral population X, and are in the process of speciating.

If my model is correct, we should see what we do see: we should see some groups of organisms (such as domestic dogs) within which interfertility is high—most matings of dogs produce viable offspring (although some matings, such as between Great Danes and Chihuahuas, either do not happen or present difficulties in producing viable offspring). We should also see groups of organisms (such as dogs and cats) which never produce viable offspring at all. We should also see groups of organisms which are intermediate between the two extremes, like lions and tigers (where matings, which do not occur in nature, frequently do produce viable offspring although there is a reduced probability of mating resulting in offspring) or horses and donkeys (where matings sometimes produce offspring, but those offspring are almost invariably sterile).

So, Magellan: to the extent that you can decipher my complex and cryptic diagram with words and drawings on it, can you please tell me why it cannot possibly work? Don't ask me for evidence supporting it (although I've already supplied some), and don't start talking about some different, unrelated model (such as your model, where interfertility is always and everywhere either 100% or 0).

I just want to see if you can understand the model in the first place.

Some day. Maybe.

sylas

March 25th 2011, 03:34 PM

You write posts directed at me telling me that you are uninterested in my response.

I have never said anything of the sort. I do remain interested in your responses, and I read them.

That does not mean I will always reply. I will, however, usually attempt to answer a direct question, if the answer can be given in a sentence or two. Direct questions which are purely substantive are best; questions which have been already asked and answered I may ignore, or else simply reiterate the answer.

In this case, I was saying that after reading your response (at msg #1235, responding to my #1231) I did not see any need to revise or explain the original post. I am happy for my #1231 and your #1235 to stand on the record as already written.

My estimation is that you are mostly trolling; posts like the above about my being uninterested followed by a bare insult do tend to reinforce this suspicion. If you aren't trolling, then all I can do is reiterate that I do find your responses interesting, and that I have a very long standing interest in creationist/evolution discussions and how they proceed.

I will be especially interested in how you or others react to the simulation that I have now started coding, and should complete on the weekend. I will be interested if Eric considers it as a valid illustration of his model, and whether you can recognize the implications of any output I am able to obtain. I will be interested in any suggestions for extensions or changes to the program, and may be willing to help with coding any of them, for those who don't know the computer language I am using. (I'm using C)

I haven't run anything yet, so I don't know for sure; but I suspect it will be able to show by example what I said already in #1231 about the errors in your criticism of Eric's model.

Cheers -- sylas

ericmurphy

March 25th 2011, 03:53 PM

I wish we could get Magellan to understand the difference between criticizing my model, and making up his own model of how he thinks evolutionary theory asserts speciation happens and then criticizing that model. Time after time he makes some criticism of a process that is simply not part of my model. No part of my model asserts that, e.g, no member of population A which cannot interbreed with B can have a descendent which can breed with B, or that once one member of A cannot breed with B there can be no other members of A than can breed with B, or that there is a single "factor X" which all by itself bars interfertility, or that interfertility is always 100% or 0.

Before we can even get to the point of deciding whether or not my model describes reality, we have to get to the point of deciding if my model does what I claim it does. And we can't get there until Magellan can figure out what my model does.

rogue06

March 25th 2011, 03:57 PM

ericmurphy

March 25th 2011, 04:07 PM

ETA: I noticed and error in Post #1253. I have the axes reversed. The Y axis (the vertical axis) represents interfertility, and the X axis (the horizontal axis) represents time. Other than that, the post remains the same.

magellan004

March 25th 2011, 07:39 PM

You were wrong the first two times, and you'll be wrong this time. And the time after that. And the time after that. And every time you raise this bogus "argument."

You still think it all has to happen in a single generation. How many times do we have to tell you this?

http://www.planet-deepblu.com/~eric/graphic_links/InterfertilityVsDifferences.png

It doesn't "have to happen" that way under evolutionary theory.

LEARN MY MODEL. Stop making criticisms of your OWN wrong notions of how you think the model works, and address my actual model.

We've corrected you innumerable times on this idiot notion that a single "factor X" results in an inability to interbreed. Look at this diagram again:

http://www.planet-deepblu.com/~eric/graphic_links/InterfertilityVsDifferences.png

You can disagree that this is the case if you want. But it's part and parcel of my model. If you want to address my model, then you HAVE TO ADDRESS MY MODEL. You can't keep changing things around about my model and then criticizing it as if it had those changes.

It doesn't.

The "errors in your reasoning" are that you are not addressing my model. You are making up your OWN model, which CANNOT produce speciation, and then criticizing THAT model.

I don't CARE if your model can't lead to speciation.

In your graph of Differences / Interfertility - what does 'Differences' stand for? How is it calculated. For example do you add up the different traits that all individuals have at a certain time?

What does 'Interfertility' stand for? How is it calculated/determined? Is it a function of time, numbers of individuals, numbers of children, some ability to interbreed that an individual has or that a group has? Etc.

Magellan

ericmurphy

March 25th 2011, 07:54 PM

In your graph of Differences / Interfertility - what does 'Differences' stand for? How is it calculated. For example do you add up the different traits that all individuals have at a certain time?

Magellan, read the diagram. It specifically states "(arbitrary units)." Do you understand what that means?

It's a model. It's not a recounting of a real event. "Differences" are simply genetic mutations, which is what they've been all along. If we needed to, we could take a sample of population A, sequence its genome, take another sample of population B, sequence its genome, and simply count up the differences.

I'm not going to specify how many genetic mutations result in how much of a decline in interfertility, because for the purposes of my model it doesn't matter. If it doesn't take very many differences, then speciation occurs rapidly. If it takes more differences, it just takes longer. The only way that part of my model can possibly not work is if no possible number of genetic differences between two organisms can ever have an effect on interfertility. I pointed this out to you in post #1247.

What does 'Interfertility' stand for? How is it calculated/determined? Is it a function of time, numbers of individuals, numbers of children, some ability to interbreed that an individual has or that a group has? Etc.

These kinds of questions just highlight how little of my model you've been able to puzzle out, Magellan. We have been discussing this particular model for over a week. We've been discussing "interfertility" for nearly the entirety of this thread. How can you still be asking these kinds of questions?

We're eighty-four pages into this discussion. After nearly thirteen hundred posts, you're asking foundational questions like "what is a difference?" and "what is interfertility?"

And you think you have the patience of an Indonesian…

But fortunately, it works just fine for me if you never, ever figure out this fantastically simple model of speciation. What your inability to comprehend it means is that you don't reject evolutionary theory because you have found problems with its assertions; you reject it because you simply do not understand it.

I'm not just claiming you don't understand evolutionary theory, Magellan. I'm proving you don't understand it.

sylas

March 25th 2011, 08:18 PM

Excuse me answering this one which was addressed to Eric; but I want to respond because it helps explain why I am writing a simulation, and what is the difference between having a model given in general terms, as Eric has provided, and the concrete implementation of his model, that I hope to provide as one example of something that uses Eric's model.

Eric's model is given in very general terms, as is appropriate. It would be possible to implement it as a concrete simulation in many different ways.

In your graph of Differences / Interfertility - what does 'Differences' stand for? How is it calculated. For example do you add up the different traits that all individuals have at a certain time?

Any implementation of Eric's model must have a notion of cummulative change. The model has small differences showing up in each generation, and accumulating from generation to generation, with too many differences between two individuals meaning that they are not fertile with each other. Beyond that, the model doesn't constrain the nature of these differences.

You are asking for concrete implementation specifics that are not constrained in the model; this is not a sensible question. When I put up a programmed simulation, THEN these questions will become sensible.

One way you could implement it, for example, is to have individuals represented as a sequence of bits. The number of differences between two bit strings could be defined as the number of places at which the two strings have a different bit value. My program uses another implementation.

The full biological reality is more complicated than easy abstractions like this; but that additional complexity is not what allows speciation. Speciation depends simply on having a process with the basic features Eric has described. Small changes introduced in each generation, and the accumulation of many such changes into a lineage over a long period of time; along with infertility of couples that are too far different from each other. Biology certainly has that character, no matter how much additional complexity is required for explaining life and fertility in living things.

The Muller-Dobzhansky model for "outbreeding depression" is a real biological model having this character as well; you count up the number of genes at which two prospective parents have different alleles, restricting yourself to a set of genes that are particularly relevant or more generally using a weighting function.

Eric's model is a very convenient and much simpler account that accurately captures the way this kind of outbreeding depression contributes to speciation in biology, without including all the additional details about diploid parents and haploid gametes, allelic homogeneity and heterogeneity and so on. The point is simply that there is a large number of possible genes (factors) at which we can say parents have a difference or don't have a difference; and infertility between a couple results when there are too many factors for which they are different.

By indicating arbitrary units, Eric is being consistent with his use of the model as a general framework for allopatric speciation.

What does 'Interfertility' stand for? How is it calculated/determined? Is it a function of time, numbers of individuals, numbers of children, some ability to interbreed that an individual has or that a group has? Etc.

Eric is proposing a very simple abstraction in which any given PAIR of individuals is either able to have children, or not able to have children.

In this case, the fertility across two distinct groups can be defined as the proportion of heterogenous pairs that are able to have children. A pair is heterogenous if it couples an individual from one group with an individual from another group.

If population A has 2n individuals (n male, n female) and population B has 2m individuals (m male, m female), then there are 2mn possible heterogeneous pairs.

The fraction of that number which are able to have child becomes the fertility between A and B.

Conversely, the "number of differences" could be defined as the mean expectation for the number of differences given a randomly selected heterogenous pair of the two groups.

But again, it should be emphasized that Eric's model is a general framework; not a concrete implementation for which there are unique answers to your questions.

Cheers -- sylas

ericmurphy

March 25th 2011, 08:54 PM

I can't wait until Magellan complains my model is too simple.

magellan004

March 25th 2011, 09:20 PM

Magellan, read the diagram. It specifically states "(arbitrary units)." Do you understand what that means?

It's a model. It's not a recounting of a real event. "Differences" are simply genetic mutations, which is what they've been all along. If we needed to, we could take a sample of population A, sequence its genome, take another sample of population B, sequence its genome, and simply count up the differences.

I'm not going to specify how many genetic mutations result in how much of a decline in interfertility, because for the purposes of my model it doesn't matter. If it doesn't take very many differences, then speciation occurs rapidly. If it takes more differences, it just takes longer. The only way that part of my model can possibly not work is if no possible number of genetic differences between two organisms can ever have an effect on interfertility. I pointed this out to you in post #1247.

These kinds of questions just highlight how little of my model you've been able to puzzle out, Magellan. We have been discussing this particular model for over a week. We've been discussing "interfertility" for nearly the entirety of this thread. How can you still be asking these kinds of questions?

We're eighty-four pages into this discussion. After nearly thirteen hundred posts, you're asking foundational questions like "what is a difference?" and "what is interfertility?"

And you think you have the patience of an Indonesian…

But fortunately, it works just fine for me if you never, ever figure out this fantastically simple model of speciation. What your inability to comprehend it means is that you don't reject evolutionary theory because you have found problems with its assertions; you reject it because you simply do not understand it.

I'm not just claiming you don't understand evolutionary theory, Magellan. I'm proving you don't understand it.

Do you want me to firstly understand your model?
if so, please answer my questions - I'm basically asking you to confirm that your graph deals with groups, not an individual.

Do either of the attached graphs correspond to your Differences graph?

Magellan

ericmurphy

March 25th 2011, 09:35 PM

Do you want me to firstly understand your model?

Actually, it's a matter of indifference to me whether you understand it or not. My job is to explain it in a way with anyone of remotely normal intelligence can understand it. If you still can't understand it, that makes you look bad, not me.

if so, please answer my questions - I'm basically asking you to confirm that your graph deals with groups, not an individual.

No you're not. You asked me what a "difference" is. Asking whether my graphs are of individuals or not is a different question, and one I've already answered repeatedly.

Look at this graph, Magellan:

http://www.planet-deepblu.com/~eric/graphic_links/FirstNonInterfertile.png

Each column of pixels in the dark green region corresponds to a particular number of individuals. The taller the column, the more individuals represented. We could say, for example, that each pixel corresponds to 1,000 individuals, and therefore a column 300 pixels tall would represent 300,000 individuals.

I explained this to you at least a week ago. You must have forgotten.

Do either of the attached graphs correspond to your Differences graph?

The first one is the closer of the two. Interbreeding, as you like to say, takes place between individuals, not groups. The "differences" axis on my graph corresponds to the number of differences between the genome of one individual and the genome of another individual.

magellan004

March 25th 2011, 10:03 PM

Actually, it's a matter of indifference to me whether you understand it or not. My job is to explain it in a way with anyone of remotely normal intelligence can understand it. If you still can't understand it, that makes you look bad, not me.

No you're not. You asked me what a "difference" is. Asking whether my graphs are of individuals or not is a different question, and one I've already answered repeatedly.

Look at this graph, Magellan:

http://www.planet-deepblu.com/~eric/graphic_links/FirstNonInterfertile.png

Each column of pixels in the dark green region corresponds to a particular number of individuals. The taller the column, the more individuals represented. We could say, for example, that each pixel corresponds to 1,000 individuals, and therefore a column 300 pixels tall would represent 300,000 individuals.

I explained this to you at least a week ago. You must have forgotten.

The first one is the closer of the two. Interbreeding, as you like to say, takes place between individuals, not groups. The "differences" axis on my graph corresponds to the number of differences between the genome of one individual and the genome of another individual.

Here is a close-up of your graph.
Individual A has 8 differences and can interbreed.
Individual B has 9 differences and can interbreed.
Individual C has 10 differences and cannot interbreed.

Any complaints?

Magellan

ericmurphy

March 25th 2011, 10:12 PM

Here is a close-up of your graph.
Individual A has 8 differences and can interbreed.
Individual B has 9 differences and can interbreed.
Individual C has 10 differences and cannot interbreed.

Any complaints?

Well, sort of. Except that there is as yet no individual C. With time, some individuals will have (and here I'm going to multiply all your "differences" by a thousand so they're not quite so ridiculous) 10,000 differences, and eventually all will have at least that many.

So far we're good, so long as you remember: my position is that a model like this is inherently unrealistic; at least, it is less realistic than a model that looks like this:

http://www.planet-deepblu.com/~eric/graphic_links/GeneticDriftV2.png

So don't waste too much time claiming I agree with you that interfertility is either present or absent. I don't agree with that. My point here is to show that even making that assumption, my model still works.

magellan004

March 25th 2011, 11:31 PM

Well, sort of. Except that there is as yet no individual C. With time, some individuals will have (and here I'm going to multiply all your "differences" by a thousand so they're not quite so ridiculous) 10,000 differences, and eventually all will have at least that many.

So far we're good, so long as you remember: my position is that a model like this is inherently unrealistic; at least, it is less realistic than a model that looks like this:

http://www.planet-deepblu.com/~eric/graphic_links/GeneticDriftV2.png

So don't waste too much time claiming I agree with you that interfertility is either present or absent. I don't agree with that. My point here is to show that even making that assumption, my model still works.

You've lost me.
In the green graph (Post 1263) you have two vertical axis- 1. Number of individuals and 2. Interfertility % . I do not understand how you can have these two vertical axis on one graph.

In the pink graph (Post 1265) you have lines and shapes everywhere. I can't understand what it represents.

Can you draw up some sample data that those two graphs (The Green Graph and the Pink Graph) might be drawn from?

I don't know whether you are talking about 'The number of individuals in Group B in Year 1', 'The number of average differences between every animal in both group A and Group B' etc.

I simply have no idea what your graphs show. Maybe if you make up some dummy data it will help. I will then try to draw a graph from the data and hopefully my graphs will resemble your graphs.

So can you suggest some data for the Green graph and some data for the Pink Graph?

Magellan

ericmurphy

March 25th 2011, 11:58 PM

You've lost me.

That typically happens when you start feeling cornered.

In the green graph (Post 1263) you have two vertical axis- 1. Number of individuals and 2. Interfertility % . I do not understand how you can have these two vertical axis on one graph.
It happens all the time, Magellan. In my GPS/cyclocomputer software, there are three vertical axes: heart-rate, speed, and altitude. All of them are plotted against the horizontal axis, which is distance.

In the pink graph (Post 1265) you have lines and shapes everywhere. I can't understand what it represents.

Then I suggest you re-read my descriptions, which by this point are pretty detailed and exhaustive.

Can you draw up some sample data that those two graphs (The Green Graph and the Pink Graph) might be drawn from?

Why? How would sample data help? You've got number of differences on the horizontal axis, and number of individuals on the vertical axis. What's the problem? You do know how to read a histogram, right?

I don't know whether you are talking about 'The number of individuals in Group B in Year 1', 'The number of average differences between every animal in both group A and Group B' etc.

Why don't you know, Magellan? I've explained it a million times already. For each colored region, the height of each column of pixels corresponds to the number of individuals in one population having a specific number of differences in their genome compared to individuals in the other population. The height of the column gives the number of individuals, and the distance along the X-axis gives the number of differences those individuals have.

I simply have no idea what your graphs show.
I've presented various versions of these graphs at least a dozen times now, and explained at least some portion of them every time I've presented them. I really don't know why you find them so mysterious; no one else seems to be having any trouble with them at all.

Maybe if you make up some dummy data it will help.
The data is in the graph. If you want to represent each pixel on the X-axis as a particular number of differences, such that one pixel to the right of the origin represents one difference and 800 pixels to the right of represents 800 differences, I have no objection to that.

I will then try to draw a graph from the data and hopefully my graphs will resemble your graphs.

Why would you draw new graphs that look like my graphs? What would that accomplish? You could just do a screen grab of my graphs and it would accomplish exactly the same thing!

So can you suggest some data for the Green graph and some data for the Pink Graph?

I just did: height of each column represents individuals, distance to the right of the origin represents differences. I don't know why you think assigning a particular value to each pixel matters; I'm not asking you to accept any data at all. I want you to understand what the model represents.

But we're not arguing data, Magellan. I'm not making some claim that a particular number of differences will result in infertility and you're arguing for a greater or lesser number.

We're arguing whether a model can work. That issue is the same regardless of the quantities involved. What matters is what is being quantified.

magellan004

March 26th 2011, 12:27 AM

That typically happens when you start feeling cornered.

It happens all the time, Magellan. In my GPS/cyclocomputer software, there are three vertical axes: heart-rate, speed, and altitude. All of them are plotted against the horizontal access, which is distance.

Then I suggest you re-read my descriptions, which by this point are pretty detailed and exhaustive.

Why? How would sample data help? You've got number of differences on the horizontal axis, and number of individuals on the vertical axis. What's the problem? You do know how to read a histogram, right?

Why don't you know, Magellan? I've explained it a million times already. For each colored region, the height of each column of pixels corresponds to the number of individuals in one population having a specific number of differences in their genome compared to individuals in the other population. The height of the column gives the number of individuals, and the distance along the X-axis gives the number of differences those individuals have.

I've presented various versions of these graphs at least a dozen times now, and explained at least some portion of them every time I've presented them. I really don't know why you find them so mysterious; no one else seems to be having any trouble with them at all.

The data is in the graph. If you want to represent each pixel on the X-axis as a particular number of differences, such that one pixel to the right of the origin represents one difference and 800 pixels to the right of represents 800 differences, I have no objection to that.

Why would you draw new graphs that look like my graphs? What would that accomplish? You could just do a screen grab of my graphs and it would accomplish exactly the same thing!

I just did: height of each column represents individuals, distance to the right of the origin represents differences. I don't know why you think assigning a particular value to each pixel matters; I'm not asking you to accept any data at all. I want you to understand what the model represents.

But we're not arguing data, Magellan. I'm not making some claim that a particular number of differences will result in infertility and you're arguing for a greater or lesser number.

We're arguing whether a model can work. That issue is the same regardless of the quantities involved. What matters is what is being quantified.

I have draw a red line which I think represents a group of individuals all of which have the same number of differences.
Does an individual in Section A of the red line have the same ability to interbreed as an individual in Section B of the red line?

Magellan

ericmurphy

March 26th 2011, 12:52 AM

I have draw a red line which I think represents a group of individuals all of which have the same number of differences.
Does an individual in Section A of the red line have the same ability to interbreed as an individual in Section B of the red line?

Yes. All individuals anywhere along the red line have the same number of differences. They might not be exactly the same differences, but all of those individuals have the same number of differences.

Obviously, this model does not correspond perfectly to reality, because of course to some extent which specific mutations each of the mating individuals have has an influence on the ultimate probability of producing offspring. But this model is apparently already pushing the limits of what you can comprehend conceptually, so I don't think adding complexity is going to make your life any easier. And not adding that complexity neither detracts from nor adds to my central claim: that the more differences there are between two individuals' genomes, the lower their interfertility there is. That there may not be a precisely linear relationship between the two variables, and that some specific types of differences might have a greater or lesser effect on interfertility, does not change things. The trend remains the same.

magellan004

March 26th 2011, 02:03 AM

Yes. All individuals anywhere along the red line have the same number of differences. They might not be exactly the same differences, but all of those individuals have the same number of differences.

Obviously, this model does not correspond perfectly to reality, because of course to some extent which specific mutations each of the mating individuals have has an influence on the ultimate probability of producing offspring. But this model is apparently already pushing the limits of what you can comprehend conceptually, so I don't think adding complexity is going to make your life any easier. And not adding that complexity neither detracts from nor adds to my central claim: that the more differences there are between two individuals' genomes, the lower their interfertility there is. That there may not be a precisely linear relationship between the two variables, and that some specific types of differences might have a greater or lesser effect on interfertility, does not change things. The trend remains the same.

OK. So in the attached diagram A and B have the same number of differences and the same ability to interbreed.

So what does the right axis - the 'Interfertility axis' signify (for A and B)?

Magellan

ericmurphy

March 26th 2011, 02:26 AM

OK. So in the attached diagram A and B have the same number of differences and the same ability to interbreed.

So what does the right axis - the 'Interfertility axis' signify (for A and B)?

Nothing—for A or B. In this simplified model, any individual in the gray region (i.e., all of them, with one exception) is 100% interfertile with an individual in the other population. Since any organism except for the one organism at the very tip of the region circled in red is 100% interfertile with members of the other population (in this unrealistic, drastically-simplified model), every other organism within the green region can interbreed with every other organism in the other population.

You seem to be under the misapprehension that in this particular diagram, the shape of the green region has something to do with interfertility. It doesn't. Interfertility is either 100% or zero, depending on whether the organism in question is in the gray "region of interfertility" or not. If an organism is within the gray region, it can potentially interbreed with individuals in the other population. If it's to the right of that region, it cannot.

I'm wondering, though, why you were asking questions about one diagram in your last post, and a different diagram in this post. You do realize that the two diagrams illustrate different models, right? One where interfertility declines as a function of the number of differences, and one where interfertility is 100% below a certain number of differences, and zero above that number? I have mentioned that a few times so far, including in the explanation where this diagram was originally posted.

Seriously, Magellan: are you even reading my explanations for these diagrams?

You keep asking questions about these diagrams that have been answered over and over again. One gets the distinct impression you're stalling for time. The problem is, there is no clock to run out.

ericmurphy

March 26th 2011, 02:41 AM

I have to say: if my aim here were actually to get Magellan, personally, to understand my model, I'd have given up in frustration by now. It's simply astonishing how much difficulty this ludicrously-simple model is presenting to him. The model has essentially two variables—number of individuals and number of mutations—and one condition—increasing differences either reduce or eliminate interfertility. That Magellan is floundering so badly here would be disconcerting if not for the likelihood that he's just pretending.

But my aim here is just to simply and straightforwardly state the parameters of my model so that someone of reasonable intelligence can understand it. If Magellan can't understand it anyway, that's sad. If he's only pretending, that's inexplicable.

But he's not going to have any luck showing speciation under my model is impossible until he at least understands my model. And the way things are going, that could take a while.

I'm thinking maybe by the end of the year.

ericmurphy

March 26th 2011, 03:23 AM

Maybe this will help. Here's a revised diagram of my "sudden infertility" model, the one where above a certain number of mutations, interfertility suddenly drops to zero:

http://www.planet-deepblu.com/~eric/graphic_links/FirstNonInterfertileLine.png

The blue line shows interfertility for any given number of mutations. Below that number, interfertility is 100%. Above that number, it is zero.

The green region once again shows the distribution of number of differences between one mutation and another at a particular point in time. At this point in time, exactly one individual has a number of mutations above the critical number. At earlier times, none did. At later times, more than one will. At still later times, all individuals will have at least that number.

At that point, we will definitely have two different species.

ericmurphy

March 26th 2011, 03:36 AM

And just to show the depth of Magellan's confusion:

Here's a screen shot of a portion of the trace from my GPS/HRM software:

http://www.planet-deepblu.com/~eric/graphic_links/MultipleYs.png

The green scale along the Y axis is speed in MPH, and the blue scale is altitude in feet above sea level (the scale for the red trace is at the far end of the graph, about 1,500 pixels to the right, and is the scale for heartrate in BPM. The bottom of the red region at the top of the graph is at about 170 BPM).

In essence, Magellan is looking at the blue trace and asking me what the beats-per-minute scale has to do with that blue trace.

magellan004

March 26th 2011, 03:37 AM

ericmurphy

March 26th 2011, 03:45 AM

That 'Green graph' model seems fine to me.

Probably because it is the less realistic of the two. And don't forget: I've already told you I disagree with your assumption that interfertility can only be 100% or zero.

You said there were two models. (The pink graph one , and the green graph one).
Are they both 'Eric's model' ? I think you challenged me to find something wrong with 'your model'.

I've already explained, in the post right before the one you're quoting, why there are two models and what the difference is between them. I've explained to you multiple times the reason I have two models is to show that even with your insistence that interfertility can only be 100% or zero—a point I maintain my disagreement with—my model will still result in speciation, and therefore your objections on that issue are a red herring.

This should not be news to you, Magellan. I've been talking about two different models for more than a week—since post #943.

Just to be sure - Is this the model that you are presenting? - (attached)

No. The model I'm presenting assumes that interfertility declines with increasing differences in genome. I've illustrated the model with the grotesquely-simplifying assumption that interfertility can only be 100% or zero to show that your insistence on that point does not help you, nor does it make my model unworkable.

It's simply a less realistic model.

Faid

March 26th 2011, 04:17 AM

Next post by Mags:

"Let me get this straight: What exactly do you mean by 'model'? Also I'd like an explanation for the units you use for each axis. Yes, again, I didn't quite catch it the eleventh time. And what is 'realistic' supposed to mean? Can you draw another graph that looks more like this pack of tangled lines I just made in MS Paint, and I find significant for some reason? Oh and and and, can you tell me what your model is, and if it's not the same as the model you're presenting now, why are you presenting it? And where's a single individual in both models? And what does "does" mean? And why are there more than one axis? What, giving up so soon"?

magellan004

March 26th 2011, 05:49 AM

Why?

Explain yourself for once.

EDIT: Let's try this: When group A and Group B have speciated, is it "very, very hard" for them to interbreed, is it "almost impossible", or is it "impossible"?

No "you tell me", no "evolutionists think". I want to know what YOU think. It should be obvious by your previous descriptions of your 'models', but I want you to irrevocably state it.

You are going around in circles -
I pointed out that for nature to arrive at a position where no American can interbreed with an Aborigine we would have to start with Eric (who can interbreed with an Aborigine) having a child who cannot interbreed with an Aborigine.

There's no 'Eric finds it hard to interbreed with aborigines'. There's no 'Humans find it difficult to interbreed with Chimps'. We are talking about 'This CANNOT breed with that' That is not my formula. That is YOUR formula.

YOU did not specify that 'difficult to interbreed ' was a criteria for Speciation.
If Eric does find it difficult to interbreed with Aborigines guess what ? Eric is a member of the same species as aborigines. YOUR formula.

YOUR test of Speciation IS NOT a level of difficulty.
If Eric cannot interbreed with Aborigines then he is not in the same Species as Aborigines.

If Eric can (even if he has to raise his blood pressure) interbreed with Aborigines and Eric's child cannot interbreed with Aborigines then Eric's child is in a separate Species to Aborigines.

So here is an absolute, total , complete red herring-

If, in your hypothetical model, Eric were to have a child for which it would be impossible to breed with "aborigines" or whatever other group, then it should be almost impossible for Eric himself to do so in the first place

Q. 'Can Eric's child interbreed with Aborigines ?'
A. 'Eric's child finds it almost impossible to interbreed with Aborigines.' <--- RED HERRING

Q. 'Can Eric's child interbreed with Aborigines ?'
A. 'Eric's child can interbreed with Aborigines.' <--- Same Species

Q. 'Can Eric's child interbreed with Aborigines ?'
A. 'Eric's child cannot interbreed with Aborigines.' <--- Different Species

Get it?

If you don't like it then answer this -

Q. 'Can Eric's child interbreed with Aborigines ?'
A. 'Eric's child finds it almost impossible to interbreed with Aborigines.'
Conclusion - Eric's child IS / IS NOT a member of the same species as Aborigines.

Pick an alternative.

Magellan

magellan004

March 26th 2011, 06:49 AM

So Mags: If A is different than B in some way, how exactly is B not different from A in the same way?

I hope this helps-

According to relativity when you walk you are actually staying still and the Earth is moving about underneath and all around you.

Let's say two parents have a child that has 160 mutations.
If you want to turn this on its head and say that the parents are different to the child because the parents 'un-mutated' then go for it.

But what will that achieve?

Magellan

magellan004

March 26th 2011, 07:08 AM

sylas

March 26th 2011, 09:24 AM

There is only one issue to address - A parent pair that can interbreed with Group A has a child that cannot interbreed with Group A. Is that possible?

Yet again. Individuals don't breed with a group. They breed with other individuals. This has been pointed out many many times in the thread, and you STILL aren't getting it.

What Eric's model involves -- and what biology involves -- incorporates these cases:

An individual can breed with ANY other individual in group A.
An individual can breed with NO other individual in group A.
An individual can breed with SOME other individuals in group A; some may be anything from 0% to 100%.

OK? Speaking of an individual "Breeding with group A" or "Not breeding with group A" obscures the case of partial isolation, which is what the model predicts, what is represented in Eric's graphs, and what appears in biological reality.

It's not a matter of breeding with group A or not breeding with group A. It is a matter of breeding with some proportion of group A, and that can range from 0% to 100%, or anything in between.

This will be more obvious when the simulation program based on Eric's model is presented. In Eric's model, speciation is said to occur when NO individual in group A can breed with ANY individual in group B.

Speciation is a property of groups, not of individuals; another incorrect claim which is not part of the definition, and not part of Eric's model is to say that an individual which cannot breed with anyone in group A must be from a different species. Not so; they are only part of another species if they belong to a POPULATION (a freely interbreeding group) ALL of which are isolated from all individuals in group A.

After all, an individual that happens to be sterile (unable to breed with any other individual anywhere) is not thereby suddenly a new species all by themselves.

Cheers -- sylas

Faid

March 26th 2011, 09:26 AM

You are going around in circles -That's because I'm chasing you, Mags.

I pointed out that for nature to arrive at a position where no American can interbreed with an Aborigine we would have to start with Eric (who can interbreed with an Aborigine) having a child who cannot interbreed with an Aborigine.I pointed out that that is not the case. It would be already almost impossible for Eric to breed with aborigines (in that parallel world where there has been a reproductive barrier between the "Eric" group and the "aborigine" group for thousdands of generations). Sperciation is GRADUAL, as I explained.

There's no 'Eric finds it hard to interbreed with aborigines'. There's no 'Humans find it difficult to interbreed with Chimps'. We are talking about 'This CANNOT breed with that' That is not my formula. That is YOUR formula.
Completely untrue, since I already told you that, in MY formula, those stages have to be crossed before getting to "impossible to interbreed". It is part of the process.

Is it there in YOUR formula? Yes or no?

Come clean for once.

YOU did not specify that 'difficult to interbreed ' was a criteria for Speciation.Did I say it was? It is part of the PROCESS leading to speciation. It is YOU who apparently claimed that it would have to be a criteria, in your inane "only if species means 'it is very hard for humans to breed with chimps'" post. THAT is what I want you to explain, assuming you have the wit and spine.

If Eric does find it difficult to interbreed with Aborigines guess what ? Eric is a member of the same species as aborigines. YOUR formula.Did I say otherwise? I simply explained the PROCESS that will lead us to speciation, a PROCESS that you wish to forget for some weasely reason

YOUR test of Speciation IS NOT a level of difficulty. Did I say I was testing for speciation? No. Were YOU testing for speciation? No. You just made a bone-headed claim that shows you wish to conveniently leave that "level of dificulty" aside, undoubtedly to pull some silly twist later. Did you really think we'd let you?

If Eric cannot interbreed with Aborigines then he is not in the same Species as Aborigines.

If Eric can (even if he has to raise his blood pressure) interbreed with Aborigines and Eric's child cannot interbreed with Aborigines then Eric's child is in a separate Species to Aborigines.
So?

So here is an absolute, total , complete red herring-

Q. 'Can Eric's child interbreed with Aborigines ?'
A. 'Eric's child finds it almost impossible to interbreed with Aborigines.' <--- RED HERRING
Did I say that? No. No wonder it's a red herring, it's a complete mischaracterisation on your part.

Q. 'Can Eric's child interbreed with Aborigines ?'
A. 'Eric's child can interbreed with Aborigines.' <--- Same Species
Q. 'Can Eric's child interbreed with Aborigines ?'
A. 'Eric's child cannot interbreed with Aborigines.' <--- Different SpeciesDid I question that? No. The question is, in that case, could Eric himself fully and without any problems interbreed with aborigines? The correct answer is NO. Speciation is a GRADUAL PROCESS, and it's not easy to pin it down to a single individual. Sure, there is some point in which that 99.999999% infertility becomes 100% infertility. But if that is the specific point when Eric's child is born, still the interfertility loss (in regard to the other group) between Eric and his child is minimal.

Get it?
Do you? It's not all-or-nothing. It's a GRADUAL PROCESS, over thousands of generations.
If you don't like it then answer this -

Q. 'Can Eric's child interbreed with Aborigines ?'
A. 'Eric's child finds it almost impossible to interbreed with Aborigines.'
Conclusion - Eric's child IS / IS NOT a member of the same species as Aborigines.

Pick an alternative.No need. in that case, both Eric and his child are IN THE PROCESS of speciation regarding aborigines. And if your problem is that we cannot pin down the exact moment tht speciation takes place, well, congratulations: You just realized what we've been telling you for 90 pages.

Happy?

Faid

March 26th 2011, 09:32 AM

I hope this helps- I doubt it.

According to relativity when you walk you are actually staying still and the Earth is moving about underneath and all around you. Is that how relativity works in Magsworld? Interesting. Anyway, no help so far in getting an answer.

Let's say two parents have a child that has 160 mutations.
If you want to turn this on its head and say that the parents are different to the child because the parents 'un-mutated' then go for it.GObbledygook. First of all, the analogy is incorrect (because BOTH groups will change in time, as I told you). But even in that analogy: If the child is different from the parents, are the parents not different from the child?

Surely you can answer such a simple question?

But what will that achieve?It will achieve the almost impossible task of getting a straight answer from you. Do you have the necessary honesty and intellect to respond to this UNBELIEVABLY simple question, Mags? If not, well, you're no help (and beyond help).

Stand and deliver, Magsie.

sylas

March 26th 2011, 10:49 AM

This post is a more biologically detailed account of one possible way in which two geographically isolated populations may evolve a persistent heritable genetic isolation from each other.

This is something I have only learned about in the last week, as I was reading the paper by Orr which I had cited in #1148. The paper is
Orr H.A. and Turelli M. (2001) The evolution of postzygotic isolation: accumulating Dobzhansky-Muller incompatibilities. (http://www.ncbi.nlm.nih.gov/pubmed/11475044), in Evolution 55(6) pp 1085-94.

I've been checking this out a bit more thoroughly and I found it interesting; others may do so as well, so I am taking a stab at explaining it. Others in the thread (Eric? Faid? anyone?) who have a some biological background and can see any errors in my description of Dobzhansky-Muller incompatabilities please do point them out.

Let me emphasize then: this post is not at all necessary to follow Eric's model. People who can't follow Eric's model will certainly find this particular example to be even more confusing. On the other hand, readers who DO understand Eric's model (pretty much everyone in the thread bar one, it seems) may like to see how it works on a concrete biological example, given in terms of genes, alleles and mutations.

Eric's model is a general framework; this is a concrete consideration of an particular biological case that matches Eric's model. Furthermore, this is a case in which an individual in group A can develop 100% isolation from group B in a single generation, and then pass that on to descendants until eventually every individual in group A is 100% isolated from every individual in group B. That is the point at which we can say speciation has occurred; and not before.

Speciation is a property of groups. It is not part of Eric's model, or a consequence of the definitions used in biology or given in the thread, to say that an individual which cannot breed with anyone in group A must be from a different species. Not so; they are only part of another species if they belong to a POPULATION (a freely interbreeding group) ALL of which are reproductively isolated from all individuals in group A.

This concrete example is a simple case of what is called "Dobzhansky-Muller isolation", involving the alleles for different genes that disrupt each other. In this example, there is only one mutation involved in the isolation; yet you still have partial isolation of the two groups starting at 0% and ending at 100% isolation, passing through a spectrum of partial isolation values along the way, just as Eric's graphs of his model illustrates.

Step 1. A single combined population

Start with a single combined population, which has a certain essential gene, and the population has two alleles present for the gene: "a" and "b". The diploid individuals in the original combined population are either "aa", "ab" or "bb", and there's no difference in fitness between these forms.

Step 2. Geographical isolation

Now we have a geographical isolation event. This gives two groups, and both these two groups have the same distribution of "aa", "ab" and "bb" as was in the original population. Genetically, the two groups are identical; they differ only by being on (for example) opposite sides of a river that prevents them finding mates on the other side.

Step 3. Elimination of different alleles from group A, and group B; by genetic drift

Over many many MANY generations, the two groups evolve independently of each other. Given the assumption that there is no selection between the three forms "aa", "ab" and "bb", it is predicted (population genetics) that the proportion of "a" and "b" alleles will take a random walk. Eventually, the one or other of the "a" allele or "b" allele should get eliminated from the population.

Let us suppose that eventually, group A has eliminated the "b" allele, and group B has eliminated the "a" allele. This means group A are all homozygous for "aa", and group B is homozygous for "bb"; and that will remain the case ever after -- excepting that new alleles can be expected show up from time to time by mutation.

Step 4. A mutation event giving a new allele in a different gene.

Note that so far, there is no detectable loss of fertility or fitness; there may be no apparent external effect at all.

But now suppose that in group A, a new allele arises, by mutation, for a second DIFFERENT gene. Assume also that this new allele interferes with the operation of the "b" allele of the first gene, but not with the "a" allele. (This kind of effect is observed in biology also.) This mutation conveys 100% sterility from group B, in a single generation, but for only one individual in group A -- the individual with the new mutation.

Step 5. Fixation of the new allele by drift.

If this mutation shows up in group B, it is eliminated immediately; the child is sterile within group B. If it shows up in the original population, it is highly deleterious, making a child infertile with about 75% of the original population. But if it shows up in group A, after the "aa" form of the first gene is fixed, then this new allele for the second gene has no effect on fertility with potential mates, and possibly no apparent effect at all, unless some experimenter pops in and starts testing for fertility between an individual of group A with the new mutation and individuals from group B.

Since it is at first only ONE individual in group A that is infertile with all of group B, there is certainly no specuation... the definition requires that every individual of group A be infertile with every individual of group B.

As group A continues to evolve independently and geographically isolated from group B, you have the proportion of A carrying the new allele ranging up and down as a random walk. As it does so, the proportion of individuals from group A that are 100% infertile with group B changes; and hence the proportion of possible heterogenous pairs across group A and group B that happen to be infertile changes as well. It reaches 100% when and if the new allele becomes fixed in population A. This can occur by drift, assuming no selection on the new mutation in the absence of the "b" allele.

Step 6. Removal of the geographical barrier, showing that speciation has occured.

Once the new mutation has been fixed in group A, every individual in group A is "aa" for the first gene, and also homozygous for the new allele of the second gene that happens to disrupt "b".

Now suppose that groups A and B are again able to mix freely -- the geographical barrier has been removed. Any cross between group A and group B will be heterozygous for the first gene ("ab"), and they will also carry one copy of the allele in a second gene that disrupts the "ab" form of the first gene. This, by hypothesis, means that the hybrid cross is not viable, and this holds for all possible hybrid couples between groups A and B.

Hence, the two groups are now fully isolated from each other, even without the geographical barrier.

* * * * *

A couple of interesting points about this mechanism. First, there's no selection involved. Everything is by genetic drift. Second, it must involve at least two different genes. Third, it only requires a single mutation. In practice there is likely to be more than one, but it does not require many mutations.

Third -- and this is the point which is least obvious, I guess -- this is close to inevitable, if you wait long enough. Once populations are isolated, it is inevitable that they will at some point be fixing different alleles for certain genes. Also, since genes typically interact with each other a great deal, and because there are so many ways to upset their operation, it is quite common to get mutations in one gene that disrupt the operation of another. If a new mutation in one gene happens to disrupt a certain allele for a second gene, but the mutation is in a geographically isolated sub-population from which that second allele has been previously eliminated, then the new mutation is fine; it never meets up with the allele that it disrupts, and so avoids the strong selective pressure to eliminate the allele in a larger combined population.

Cheers -- sylas

ericmurphy

March 26th 2011, 12:18 PM

You are going around in circles -
Actually, Magellan, if anyone here is doing donuts in the parking lot here, it's you.

I pointed out that for nature to arrive at a position where no American can interbreed with an Aborigine we would have to start with Eric (who can interbreed with an Aborigine) having a child who cannot interbreed with an Aborigine.

Even if this were literally true, my model shows it doesn't matter. You still get speciation.

There's no 'Eric finds it hard to interbreed with aborigines'.

Actually, yes, there is. As has been explained to you over and over again, interfertility declines with increasing genetic distance. It doesn't just suddenly go to zero. There is no requirement that anything like this happens (although as I have shown, speciation could still happen under your artificial requirement that interfertility be either 100% or zero).

There's no 'Humans find it difficult to interbreed with Chimps'. We are talking about 'This CANNOT breed with that' That is not my formula. That is YOUR formula.

Perhaps it's escaped your notice, Magellan, but no one is talking about your "formula." As several posters have pointed out to you now, it doesn't matter if you can come up with a plainly unrealistic model under which speciation can't happen (although so far you haven't even actually managed that). You're supposed to be criticizing evolutionary theory, not your own strawman version of that theory.

YOU did not specify that 'difficult to interbreed ' was a criteria for Speciation.
I certainly did, Magellan. Once again:

http://www.planet-deepblu.com/~eric/graphic_links/InterfertilityVsDifferences.png

If Eric does find it difficult to interbreed with Aborigines guess what ? Eric is a member of the same species as aborigines. YOUR formula.

But if some descendant of Eric finds it impossible to interbreed with Aboringes, then guess what? That descendant is a different species from Aborigines.

And so far, no argument from you on why this can't happen.

YOUR test of Speciation IS NOT a level of difficulty.
It's a model, Magellan. Not a test. Part of my model IS increasing difficulty in interbreeding (which, for the short-of-memory, is not actually happening anyway, due to reproductive isolation) with increasing genetic distance.

If Eric cannot interbreed with Aborigines then he is not in the same Species as Aborigines.

If Eric can (even if he has to raise his blood pressure) interbreed with Aborigines and Eric's child cannot interbreed with Aborigines then Eric's child is in a separate Species to Aborigines.

You say this like it's some sort of problem. In fact, it's pretty much the definition of speciation. If you want us to believe speciation cannot happen, then you have to give a reason why it cannot ever be the case that if Eric can interbreed with Aborigines, some descendant of Eric cannot interbreed with Aborigines.

So far, you're not having much luck with that task.

So here is an absolute, total , complete red herring-
If, in your hypothetical model, Eric were to have a child for which it would be impossible to breed with "aborigines" or whatever other group, then it should be almost impossible for Eric himself to do so in the first place

It's not a "red herring," Magellan. It's a description of how things work in the real world. As opposed to your absurd notion that interfertility goes from 100% to 0 in a single generation.

Q. 'Can Eric's child interbreed with Aborigines ?'
A. 'Eric's child finds it almost impossible to interbreed with Aborigines.' <--- RED HERRING

Nope. Just an accurate description of the process of speciation.

Q. 'Can Eric's child interbreed with Aborigines ?'
A. 'Eric's child can interbreed with Aborigines.' <--- Same Species

Q. 'Can Eric's child interbreed with Aborigines ?'
A. 'Eric's child cannot interbreed with Aborigines.' <--- Different Species

Get it?

Faid's not the one with comprehension problems here, Magellan.

If you don't like it then answer this -

Q. 'Can Eric's child interbreed with Aborigines ?'
A. 'Eric's child finds it almost impossible to interbreed with Aborigines.'
Conclusion - Eric's child IS / IS NOT a member of the same species as Aborigines.

Pick an alternative.

They're both the same thing, Magellan. If two individuals find it almost, but not quite, impossible to produce viable offspring, they are the same species. If they find it completely impossible to produce viable offspring, they are most likely different species.

Maybe you need to review this diagram again:

http://www.planet-deepblu.com/~eric/graphic_links/SpeciesCurve.png

ericmurphy

March 26th 2011, 12:41 PM

Your graph shows Speciation of a group.

Yes, Magellan, that's right. It doesn't show the speciation of an individual, because that would not make any sense. Individuals do not "speciate."

It might save a lot of time
The only thing that's going to save any time is for you to actually learn my model.

if you could answer this -
If one individual cannot interbreed with another individual are those two individuals members of the -
1. Same species
2. Different Species
3. Not known?

Based on a single piece of information, it's not known. If two individuals can interbreed, then by definition (the definition I have been using consistently) they are the same species. If they can't interbreed, then we need to know why. Is one of them sterile, for example?

But if we have an entire population of organisms no members of which can interbreed with another population of organisms, it's pretty safe to say those two populations are not the same species.

There is no doubt that if we took two clusters, collections, gatherings, groups of individuals then we could have -
1. Every member of Group B can interbreed with group A or we could have
2. Not one member of Group B can interbreed with Group A or we could have
3. Some members of group B can interbreed with Group A.

But so what? The only thing of interest is 'Is it possible to get there (two groups unable to interbreed) through evolutionary processes? Just drawing a graph with an X axis labelled 'Time' does not show that it is possible.

But this does:

We start with a single, freely-interbreeding ancestral population X. All members of this population can interbreed with each other.
At some point, some event or process divides X into two freely-interbreeding subpopulations, A and B. At the time of initial separation, all members of A and B are interfertile not only with other members of their own population but also with members of the other population, and would be interfertile with members of X if there still were any.
http://www.planet-deepblu.com/~eric/graphic_links/Isolation.png
The isolating event or process could be geographic isolation due to a new mountain range forming, climate change forming a barrier between two regions, migration patterns reducing or eliminating gene flow between remote areas inhabited by the original population, or colonization of an island by either subpopulation.
Over time, genetic differences in both populations accumulate, so that the members of each population become increasingly different from members of the other population (but selective pressures minimize the differences within a population).
http://www.planet-deepblu.com/~eric/graphic_links/GeneticDriftV2.png
As those differences accumulate, interfertility between populations (if there were any interbreeding between them, which there isn't) slowly declines over time. Again, selective pressures keep interfertility within a population from declining.
http://www.planet-deepblu.com/~eric/graphic_links/InterfertilityVsDifferences.png
After sufficient genetic differences have accumulated, interfertility between A and B declines to zero. At this point, we have two separate species which cannot interbreed.
http://www.planet-deepblu.com/~eric/graphic_links/Interbreeding.png
Even if further events allow an overlap of territories between A and B, they will no longer be able to interbreed, and will remain separate species indefinitely.
As time goes on, both A and B may undergo additional speciation events, similar to the above, with both A and B taking the place of X in the sequence of events.

I understand your assertion.
I don't think you do. Your repeated questions, which have been repeatedly answered, lead me to believe that you do not understand my assertion, nor the model upon which it is based.

I understand that you can graphically illustrate your assertion.
What you have been unable to do is to show the processes at work to get to 'Cannot interbreed'.

Oh, I've been able to show them, all right. Over and over and over again. What you have been unable to do is either a) explain why those processes do not work to result in speciation, or even b) demonstrate that you understand how those processes are even alleged to work in the first place.

Please stop presenting pictures of Start, Middle, End and claiming that they show HOW it happens.

They DO show how it happens. I've given you a narrative description, with illustrations, of exactly how speciation happens. Why you think I haven't is either due to a lack of native intelligence that I find difficult to swallow, or grotesque intellectual dishonesty that I also find difficult to swallow. It's somewhat less difficult to swallow a mixture of the two.

There is only one issue to address - A parent pair that can interbreed with Group A has a child that cannot interbreed with Group A. Is that possible?

Of course it's possible: sterility. A horse and a donkey can mate and produce an offspring which can mate and produce offspring with neither horses nor donkeys.

But that's not the question here. The question is, can we start with one population of freely-interbreeding organisms, and end up with two populations of freely-interbreeding organisms, members of each population being unable to interbreed with members of the other population?

The answer to that question is, "Yes, we can." I've shown how we can. But it's just a little disturbing that after nearly thirteen hundred posts on this thread, you can't even get the question posed by your own OP right.

ericmurphy

March 26th 2011, 01:00 PM

magellan004

March 26th 2011, 02:36 PM

Based on a single piece of information, it's not known. If two individuals can interbreed, then by definition (the definition I have been using consistently) they are the same species. If they can't interbreed, then we need to know why. Is one of them sterile, for example?

But if we have an entire population of organisms no members of which can interbreed with another population of organisms, it's pretty safe to say those two populations are not the same species.

You seem to be saying that we can be sure (about membership of a Species) if two individuals belong to the same species and we can be sure if two groups belong to the same species
but -
we can't be sure about membership of different Species.
We can't say with confidence 'This belongs to a different species to that.'

In other words we don't have a reliable test for differentiating Species. There might be only one Species.

I accept that. Speciation might not ever have happened. Where biologists think it happened it might very well not have happened.

I won't disagree with that.

Magellan

magellan004

March 26th 2011, 02:39 PM

But that's not the question here. The question is, can we start with one population of freely-interbreeding organisms, and end up with two populations of freely-interbreeding organisms, members of each population being unable to interbreed with members of the other population?

The answer to that question is, "Yes, we can." I've shown how we can.
No . You just said we can't ever be really certain.

Magellan

ericmurphy

March 26th 2011, 03:03 PM

You seem to be saying that we can be sure (about membership of a Species) if two individuals belong to the same species and we can be sure if two groups belong to the same species
but -
we can't be sure about membership of different Species.
We can't say with confidence 'This belongs to a different species to that.'

In other words we don't have a reliable test for differentiating Species. There might be only one Species.

As usual, Magellan, when you try to figure out what someone else means, you completely reword what they're saying into a completely different statement, instead of just taking what they say as meaning what they say.

I'm not saying we can't tell if they might be a member of a different species. If they can interbreed with some other species, then we know for certain they're members of that other species (as I have defined the term in my model).

What I am saying is that if two organisms can interbreed, they are definitely members of the same species. If they can't, they might be, or one or both of them might not be able interbreed with each other, but still can interbreed with other members of the other species, or one or both of them might be sterile.

In short, we can definitely tell if one individual is a member of a species, but may not be able to tell if it isn't.

And what we can definitely tell is if we've got two populations of organisms, we can tell if they are the same species (the majority of individuals in one population can interbreed with the majority of individuals in the other populations), if they're different species (no member of either population can interbreed with any member of the other population), or if they are two populations formerly of the same species but in the process of speciation (where interfertility is somewhere in between, as shown in this diagram):

http://www.planet-deepblu.com/~eric/graphic_links/SpeciesCurve.png

So you're wrong: there is a reliable method for determining if one organism is a member of a particular species, even if we can't always say for certain if it's not. And there's definitely a reliable method for telling if two populations are the same species, different species, or are two populations formerly of the same species but are now undergoing speciation.

German Shepherds and Australian Shepherds: definitely the same species.
Dogs and cats: definitely different species.
Horses and donkeys: definitely formerly the same species but now in the process of speciation.

I accept that. Speciation might not ever have happened. Where biologists think it happened it might very well not have happened.

I won't disagree with that.

Well I disagree with it. Speciation has definitely happened. There is no question that it happened. We've observed that it has happened.

ericmurphy

March 26th 2011, 03:04 PM

No . You just said we can't ever be really certain.

Magellan

I said no such thing and you know it. Just because we cannot always tell if two individual organisms are not the same species (we can always tell if they are the same species) does not mean we can never tell if speciation has happened.

magellan004

March 26th 2011, 03:53 PM

As usual, Magellan, when you try to figure out what someone else means, you completely reword what they're saying into a completely different statement, instead of just taking what they say as meaning what they say.

I'm not saying we can't tell if they might be a member of a different species. If they can interbreed with some other species, then we know for certain they're members of that other species (as I have defined the term in my model).

What I am saying is that if two organisms can interbreed, they are definitely members of the same species. If they can't, they might be, or one or both of them might not be able interbreed with each other, but still can interbreed with other members of the other species, or one or both of them might be sterile.

In short, we can definitely tell if one individual is a member of a species, but may not be able to tell if it isn't.

And what we can definitely tell is if we've got two populations of organisms, we can tell if they are the same species (the majority of individuals in one population can interbreed with the majority of individuals in the other populations), if they're different species (no member of either population can interbreed with any member of the other population), or if they are two populations formerly of the same species but in the process of speciation (where interfertility is somewhere in between, as shown in this diagram):

http://www.planet-deepblu.com/~eric/graphic_links/SpeciesCurve.png

So you're wrong: there is a reliable method for determining if one organism is a member of a particular species, even if we can't always say for certain if it's not. And there's definitely a reliable method for telling if two populations are the same species, different species, or are two populations formerly of the same species but are now undergoing speciation.

German Shepherds and Australian Shepherds: definitely the same species.
Dogs and cats: definitely different species.
Horses and donkeys: definitely formerly the same species but now in the process of speciation.

Well I disagree with it. Speciation has definitely happened. There is no question that it happened. We've observed that it has happened.

Your 'majority' test is a new test.
If you use > 50% and < 50% then your diagram is wrong. I have attached a fix for you.

But more importantly, if we had a collection of 2000 lions and 1000 monkeys in one group and 2000 lions in another group we could definitely say that monkeys are the same Species as lions.

You had better rethink your 'majority' rule.

Magellan

ericmurphy

March 26th 2011, 04:09 PM

Your 'majority' test is a new test.
It's not a "new test." There have always been sterile individuals who cannot interbreed with any other individuals, Magellan.

The test for speciation is always this: when no individuals from one population can interbreed with any individuals from the other population. That a few organisms here and there can't interbreed with any individual at all does not mean speciation hasn't happened.

Seriously, Magellan; try to keep up.

If you use > 50% and < 50% then your diagram is wrong. I have attached a fix for you.

Well, since I don't use >50% and <50%, my diagram is fine. I use "close to 100%" and "zero."

And your "fix" doesn't "fix" anything. All you've done is taken out the middle region where interfertility is less than about 95% and more than about 5%. No matter how hard you try, you are not going to be able to eliminate that region. The way you've drawn it is nonsensical. You've got "definitely the same species" at 50.000000000000000001% and "definitely different species at 49.999999999999999999999%.

Do you really think that's going to work?

And, to make matters worse, I've already shown how it wouldn't matter if you could. You'd still get speciation. You'd still get from one population where essentially all members can freely interbreed to two populations where no member of one population can interbreed with any member of the other population. Look at your own curve, Magellan. It's near 100% at the beginning at it's zero at the end.

Speciation still happens.

But more importantly, if we had a collection of 2000 lions and 1000 monkeys in one group and 2000 lions in another group we could definitely say that monkeys are the same Species as lions.

How? No monkey can interbreed with any lion. No lion can interbreed with any monkey. Interfertility is zero. Two species.

You had better rethink your 'majority' rule.

Why? If you think by "majority" I mean 50.000000000000000001%, then maybe you'd better rethink what you think I mean by "majority."

Once again, Magellan: stop trying to rewrite my model into something different, and address it as it stands.

sylas

March 26th 2011, 04:22 PM

Fascinating post, sylas (and in answer to your question, no, I have no background or training in biology, or science, for that matter). It shows that speciation can happen even in the complete absence of selection pressures. I've always thought neutral drift had a much larger role to play in speciation than selection, although the critical role selection does play in the process is to keep drift under control within a population.

Quite so! Selection is a conservative force. It removes variation, and hence is the opposite of mutation which introduces it.

In the account I gave, the only role of selection is to strip out anything that makes an individual less able to mate freely within their own population. This means that the isolating mutation can only possibly arise and become fixed in the population where the allele it disrupts is not present. If the geographical isolating barrier is removed at a point where the speciation is only partially complete, then what happens is that there is an immediate strong negative selection on the new allele, and it will get removed -- resulting eventually in a combined population that is genetically the same as what we started with.

Now that you emphasize this, it strikes me that this is why sympatric speciation is so much more of an issue to explain or model. You invariably need a much richer model to have sympatric speciation, or speciation within a population that is never subject to any externalized isolation mechanisms. But that is another topic for another time, I think.

Cheers -- sylas

ericmurphy

March 26th 2011, 04:26 PM

Since Magellan seems determined to misrepresent my statements, let me illustrate what I mean when I say "majority":

http://www.planet-deepblu.com/~eric/graphic_links/Species%20Curve2.png

See that yellow arrow at the top of the diagram, Magellan? That's what I mean by "majority." I DON'T mean 50.00000000000000001%

See that yellow arrow at the bottom of the diagram, Magellan? That's what I mean by "none." As in "not any," as in "zero."

ericmurphy

March 26th 2011, 04:33 PM

Now that you emphasize this, it strikes me that this is why sympatric speciation is so much more of an issue to explain or model. You invariably need a much richer model to have sympatric speciation, or speciation within a population that is never subject to any externalized isolation mechanisms. But that is another topic for another time, I think.

Right. It appears that sympatric speciation is quite a bit rarer than allopatric speciation, at least among animals. It seems to be more common among plants, and I can think of three reasons: first, polyploidy, which often presents a complete barrier to interfertility, is much more common in plants than in animals (some domesticated varieties of wheat, for example, are hexaploid), second, most plant species produce dozens to thousands of offspring at a time, so it's not hard to imagine a scenario where in a small region spatially speaking, numerous polyploid individuals would arise simultaneously, and third, many plants are self-fertilizing, so polyploidy does not leave individuals unable to mate with any other individuals.

But, as you say, that's a topic for another time. Certain readers here are having a pretty difficult time with the comparatively simpler model of allopatric speciation.

Faid

March 26th 2011, 05:10 PM

sylas

March 26th 2011, 05:10 PM

But more importantly, if we had a collection of 2000 lions and 1000 monkeys in one group and 2000 lions in another group we could definitely say that monkeys are the same Species as lions.

Taking this seriously for a tick; the reason why this is not a problem is that biologists don't just take any old mixed up bag of organisms to compare for speciation. They take "populations" -- meaning a bag of organisms that are all freely interbreeding with each other.

Consider the example of Orcas, which has been discussed a couple of times in the thread. Recent research is bringing us to the point of recognizing that what was previously classified as one species is in fact probably at least three distinct species.

The first step in this was to note that there are different apparent races or varieties, with subtle differences between them. An alien biologist would be able to do this with humans, for example, picking up subtle differences of the various human racial varieties.

The second step is to see if these varieties mix up at all naturally. (This is the point of comparing populations.) That can be very hard to do, in general. For humans, the alien biologist would very quickly observe that the varieties do mix without restriction, and so recognize that those differences were not between species, but within a single species.

In the case of Orcas, it has been observed that the varieties don't mix, as far as we have observed so far. The question becomes -- is this because they are actually from two groups that don't mix anywhere or under any natural circumstances? Or is it simply because we've not looked hard enough?

This is where the scientific method steps in. Rather than trying to check everywhere for the existence of viable hybrids, the scientific method considers consequences of a hypothesis and attempts to falsify it. There's a consequence of divergence for genomes -- and in particular in mitochondrial genomes. (Mitochondria are passed only down the female line; you get mitochondria from your mother only. They have their own genetic sequence, quite separate from the nuclear genome.) By looking at divergence times obtained by comparisons of mitochondrial DNA you can discover roughly how long groups have been isolated from each other, to within an order of magnitude or so.

See Genomic Analysis Indicates Mulitples Species of Killer Whale (http://swfsc.noaa.gov/textblock.aspx?Division=PRD&id=16089) at NOAA for a brief introduction to this research; and here's a older quote from this thread with the journal reference.

A recent reference for this:

Morin, P.A. et. al. (2010) "Complete mitochondrial genome phylogeographic analysis of killer whales (Orcinus orca) indicates multiple species (http://genome.cshlp.org/content/early/2010/04/15/gr.102954.109.abstract)", in Genome Research vol 20, pp 908-916. (Full text of the paper is available).

Abstract:

Killer whales (Orcinus orca) currently comprise a single, cosmopolitan species with a diverse diet. However, studies over the last 30 years have revealed populations of sympatric ‘ecotypes’ with discrete prey preferences, morphology and behaviors. Although these ecotypes avoid social interactions and are not known to interbreed, genetic studies to date have found extremely low levels of diversity in the mitochondrial control region, and few clear phylogeographic patterns worldwide. This low level of diversity is likely due to low mitochondrial mutation rates that are common to cetaceans. Using killer whales as a case study, we have developed a method to readily sequence, assemble, and analyze complete mitochondrial genomes from large numbers of samples to more accurately assess phylogeography and estimate divergence times. This represents an important tool for wildlife management, not only for killer whales but for many marine taxa. We used high-throughput sequencing to survey whole mitochondrial genome variation of 139 samples from the North Pacific, North Atlantic and southern oceans. Phylogenetic analysis indicated that each of the known ecotypes represents a strongly supported clade with divergence times ranging from approximately 150,000 to 700,000 years ago. We recommend that three named ecotypes be elevated to full species, and that two additional types be recognized as subspecies pending additional data. [...]

Orca generation time is similar to humans; about 20 to 40 years. So the genetic differences MEASURED between the different non-interbreeding populations correspond to what would accumulate with divergence from a single parent population over something between 5000 to 30000 generations ago.

Orca taxonomy is under review in the light of this and other related research, and the recognition of a number of different species is likely to be official sometime soon.

magellan004

March 26th 2011, 05:25 PM

How? No monkey can interbreed with any lion. No lion can interbreed with any monkey. Interfertility is zero. Two species.

You said
And what we can definitely tell is if we've got two populations (ED Population 1 = 2000 lions and 1000 monkeys) of organisms, we can tell if they are the same species (the majority of individuals in one population (ED The majority of individuals in Population 1 ) can interbreed with the majority of individuals in the other populations) (ED The other population, Population 2 is 2000 lions) ...

Your system is bung.

Magellan

ericmurphy

March 26th 2011, 05:32 PM

You said

Your system is bung.

Magellan

Uh, no. You've forgotten completely what the definition of "population" is.

A "population" is a "group of freely-interbreeding organisms." "Freely-interbreeding" with each other, that is, since everything has to be spelled out in excruciating detail for you.

A group of lions and monkeys mixed together is not a "population," because it is not a "group of freely-interbreeding organisms." Lions and monkeys cannot interbreed.

You're still trying to find errors in definitions of words instead of actually dealing with my model.

This isn't English class, Magellan.

ericmurphy

March 26th 2011, 05:35 PM

Also, look at this again, Magellan, to see what I mean by "majority":

http://www.planet-deepblu.com/~eric/graphic_links/Species%20Curve2.png

We spend more time on this thread explaining to Magellan things like that it's still a "population" even if, out of a hundred thousand individuals, three or four are sterile, so long as the rest of them can freely interbreed than we do actually discussing my model.

It's the stink of desperation when you have to resort to these sorts of tactics to get anywhere, Magellan.

magellan004

March 26th 2011, 06:57 PM

We spend more time on this thread explaining to Magellan things like that it's still a "population" even if, out of a hundred thousand individuals, three or four are sterile, so long as the rest of them can freely interbreed than we do actually discussing my model.

Why do sterile individuals belong to a group of freely interbreeding individuals?

Magellan

Faid

March 26th 2011, 07:17 PM

You said

Your system is bung.

MagellanYou have repeatedly agreed that we are talking about freely-interbreeding populations for each group, AND that loss of interbreeding does not happen within the same group.

IOW, you're pathetic.

Faid

March 26th 2011, 07:25 PM

As predicted. Mags will now pretend he does not understand the concepts of living organisms in general, morphology, ontogeny, sexual reproduction and all, and claim inanities like the egg being a different species to the chicken, or the females in the population belonging to different species to each other, and don't get me started about eunuchs.

He's almost desperate enough to make you feel sorry for him. Almost.

Faid

March 26th 2011, 07:44 PM

And you know what's most funny, Mags?

It doesn't matter.

All your pathetic inanities have absolutely no influence to the concept of speciation, as we have defined it. Even you have agreed that we are talking about the loss of interbreeding between two groups. What we have is one group initially freely interbreeding with the other group, and the descendants of one group eventually failing to interbreed with the descendants of the other group.
And since it's the interbreeding individuals that leave descendants, it makes no operational difference in describing the process of speciation.
You can use any weird Magsworld notion you want, you can even include rocks in each group along with your beetles. It makes no difference when describing speciation.

Busted.

Let's see if you can twist and squirm your way into another evasion.

ericmurphy

March 26th 2011, 08:43 PM

Why do sterile individuals belong to a group of freely interbreeding individuals?

Magellan

Maybe because they were born from members of that group freely-interbreeding individuals? What, you think they just poofed out of nowhere?

You're getting nowhere with this tactic of trying to find a problem with the definition of species, Magellan. Especially since, as has been pointed out to you innumerable times, evolutionary theory predicts it will be a difficult concept to define.

Are you going to eventually stop quibbling about terminology and actually address my model? Or not?

magellan004

March 26th 2011, 08:43 PM

Even you have agreed that we are talking about the loss of interbreeding between two groups. What we have is one group initially freely interbreeding with the other group, and the descendants of one group eventually failing to interbreed with the descendants of the other group.
And since it's the interbreeding individuals that leave descendants, it makes no operational difference in describing the process of speciation.

That's what I thought we had agreed to - but every time I try to look at the steps involved in getting to 'two groups' Eric and Sylas introduce 'infertile individuals'.

So either infertile individuals count in the process or they don't.
That's what i am seeking to establish.
Can you have an sterile individual as one of a number of 'freely interbreeding individuals'?

If Eric says 'But that individual might be sterile therefore not able to interbreed ' then he has to exclude sterile individuals, and young, old, ill, those with a medical condition etc from his 'freely interbreeding' groups.

So - how do sterile individuals belong to a freely interbreeding group?

Any idea?

Magellan

ericmurphy

March 26th 2011, 08:51 PM

That's what I thought we had agreed to - but every time I try to look at the steps involved in getting to 'two groups' Eric and Sylas introduce 'infertile individuals'.

Magellan, how many times have you pointed out that groups are composed of individuals?

Seriously—can you possibly get your own story straight, even if you can't understand a thing anyone else is saying?

So either infertile individuals count in the process or they don't.

Count in what way, Magellan? Do infertile individuals leave any descendants? Please think before you attempt an answer.

That's what i am seeking to establish.
You're not trying to "establish" anything. You are aiming for maximum ambiguity.

Which is pretty lame-brained, because we've already explained a million times there is a certain irreducible ambiguity to the concept of "species," which is a prediction of evolutionary theory and a serious problem for special creation.

Can you have an sterile individual as one of a number of 'freely interbreeding individuals'?

What possible difference does it make, Magellan? Are you really going to argue that sterile individuals are, somehow, not members of any species at all?'

All you're doing is trying to find exceptions to a rule that we've already told you will have lots of exceptions anyway!

Why do you keep trying to support evolutionary theory and undermine special creation? I thought you rejected evolutionary theory?

If Eric says 'But that individual might be sterile therefore not able to interbreed ' then he has to exclude sterile individuals, and young, old, ill, those with a medical condition etc from his 'freely interbreeding' groups.

Why, Magellan? Explain why. Explain what possible difference it makes.

So - how do sterile individuals belong to a freely interbreeding group?

Why can't they? Where did they come from, Magellan? Are they members of the group as a result of, oh, say, common descent, maybe?

Seriously, Magellan: do you think a sterile dog is suddenly not a dog anymore?

ericmurphy

March 26th 2011, 08:53 PM

For eighty-eight pages, we have been telling Magellan that the concept of species is predicted by evolutionary theory to be impossible to completely nail down with certainty.

And for eighty-eight pages, he's been complaining about ambiguities in the definition of "species."

And in the meantime, he's getting absolutely nowhere trying to understand my model of how one freely-interbreeding population turns into two freely-interbreeding populations. Instead, he wastes his time and ours by wondering if a sterile organism is, oh, I don't know, maybe not alive anymore.

magellan004

March 26th 2011, 11:32 PM

Maybe because they were born from members of that group freely-interbreeding individuals? What, you think they just poofed out of nowhere?

You're getting nowhere with this tactic of trying to find a problem with the definition of species, Magellan. Especially since, as has been pointed out to you innumerable times, evolutionary theory predicts it will be a difficult concept to define.

Are you going to eventually stop quibbling about terminology and actually address my model? Or not?

Let me check on what you meant by this -

4. As those differences accumulate, interfertility between populations (if there were any interbreeding between them, which there isn't) slowly declines over time.

By that , do you mean that some individuals in Group B are not able to interbreed with individuals in Group A?

Or are you referring to some sort of average count of children born to couples where all Group B individuals can interbreed with Group A individuals but they have less children through those unions than preceding generations?

To be clear - All group B's used to be able to breed with Groups A's. Do you mean that in the intermediate years some individuals cannot (no shades of grey) - simply cannot bear any children with Group A individuals? Is that what you mean by declining interfertility?

Because if that is what you mean then that necessarily means that some Group B children (who 100% cannot breed with Group A individuals ) had parents that could 100% breed with Group A individuals.

Magellan

ericmurphy

March 26th 2011, 11:57 PM

Let me check on what you meant by this -

You mean, "(let's see how I can get away with misrepresenting this.)"

By that , do you mean that some individuals in Group B are not able to interbreed with individuals in Group A?

Or are you referring to some sort of average count of children born to couples where all Group B individuals can interbreed with Group A individuals but they have less children through those unions than preceding generations?

I mean interfertility is declining. It's been explained to you over and over and over again, by sylas and Faid and me, what that means.

To be clear

The last think you want is to be "clear." You want to be clear as mud.

- All group B's used to be able to breed with Groups A's. Do you mean that in the intermediate years some individuals cannot (no shades of grey) - simply cannot bear any children with Group A individuals? Is that what you mean by declining interfertility?

No. I mean what's already been said about this a million times already. Sylas has some really good posts explaining exactly what is meant by declining interfertility. Stop guessing what people mean and start reading what they say.

Because if that is what you mean then that necessarily means that some Group B children (who 100% cannot breed with Group A individuals ) had parents that could 100% breed with Group A individuals.

it means no such thing. There are probably no B2s whose parents had 100% interfertility with As. You keep making this boneheaded claim, but you've NEVER been able to substantiate it. There is absolutely no reason whatsoever why it need EVER be the case that interfertility declines from 100% to 0 in a single generation. There could be B2s whose parents had 50%, or 20%, or 10%, or 1% interfertility with As. There could be not a single B2 with parents whose interfertility with As was above a thousandth of one percent.

Unless by "parents," you mean, "distant ancestors." Is that what you mean by "parents," Magellan?

You seem to enjoy going back and reading the past half-dozen or so pages in this thread now and then, Magellan. I suggest you go back and read the last half-dozen pages of this thread a few more times until you can actually understand what is meant by "declining interfertility." I'm not going to spell it out for you over and over and over again.

At the beginning of this process, interfertility between A and B is nearly 100%. In the middle of this processes, interfertility declines from nearly 100% to nearly zero. At the end of this process, interfertility is zero, and no member of A can interbreed with any member of B, and vice versa.

As for what "declining interfertility" means: you're on your own. It's been explained often enough to you that you should be able to get it by now. If you can't get it by now, well, I guess you're just out of luck.

ericmurphy

March 27th 2011, 12:07 AM

magellan004

March 27th 2011, 12:08 AM

it means no such thing. There are probably no B2s whose parents had 100% interfertility with As. You keep making this boneheaded claim, but you've NEVER been able to substantiate it. There is absolutely no reason whatsoever why it need EVER be the case that interfertility declines from 100% to 0 in a single generation. There could be B2s whose parents had 50%, or 20%, or 10%, or 1% interfertility with As. There could be not a single B2 with parents whose interfertility with As was above a thousandth of one percent.

What is a B2?

You said 'We start with a freely interbreeding ancestral population of X. All members of this population can interbreed with each other.'

If that does not mean 'Each member of this population had 100% ability to breed with other members ' then I have no idea what you are talking about.

What does 'freely interbreeding' mean if it does not mean 'Each individual is 100% able to interbreed with another individual'?

Magellan

ericmurphy

March 27th 2011, 12:20 AM

What is a B2?

And you think I have a short memory.

A B2, as you defined it, is a member of population B which cannot interbreed with A.

You said 'We start with a freely interbreeding ancestral population of X. All members of this population can interbreed with each other.'

If that does not mean 'Each member of this population had 100% ability to breed with other members ' then I have no idea what you are talking about.

Look at this chart again, Magellan, and see if you can figure it out:

http://www.planet-deepblu.com/~eric/graphic_links/Species%20Curve2.png

We're not talking about individuals who were born sterile, or who didn't live to reproductive age, or who have some sort of congenital defect that prevents mating. We're talking about populations with, say, 100,000 members. You think there's some problem that only 999,875 of them can interbreed with others?

What does 'freely interbreeding' mean if it does not mean 'Each individual is 100% able to interbreed with another individual'?

Look at this chart again, Magellan, and see if you can possibly puzzle it out:

http://www.planet-deepblu.com/~eric/graphic_links/Species%20Curve2.png

Your obvious stalling tactics aren't going to get you anywhere, because there's no clock to run out. But every time you feign incomprehension like this, you strengthen my claim that you don't reject evolutionary theory because you've analyzed its arguments and found them wanting, but rather because you simply do not understand it, and cannot be made to understand it.

ericmurphy

March 27th 2011, 12:35 AM

For some reason, when we say a "population" is a "group of freely interbreeding organisms," that means a group of 10,000 caribou, which includes 1,500 juveniles which are not yet fertile, 1 sterile female and 7 sterile males, along with 4 older females which can no longer produce offspring, is not a "population."

Still the stink of desperation about you, Magellan.

magellan004

March 27th 2011, 12:56 AM

Taking this seriously for a tick; the reason why this is not a problem is that biologists don't just take any old mixed up bag of organisms to compare for speciation. They take "populations" -- meaning a bag of organisms that are all freely interbreeding with each other.

Consider the example of Orcas, which has been discussed a couple of times in the thread. Recent research is bringing us to the point of recognizing that what was previously classified as one species is in fact probably at least three distinct species.

That's an inconsistency in your argument.
I now doubt that you have any sort of test ( or concept even) for 'Can freely interbreed.'

Why were Orcas said to be able to freely interbreed in the first place?

But maybe you do have a test to determine whether a group of individuals can freely interbreed.

If so - can we know what it is? It didn't work with Orcas. You seem pretty confident it (the mystery test) works with Chimps and Humans.

Magellan

ericmurphy

March 27th 2011, 01:28 AM

That's an inconsistency in your argument.
Nope. It's a refusal from you to understand that the real world is not made up of this:

http://www.planet-deepblu.com/~eric/graphic_links/BlackNWhite.png

but rather of this:

http://www.planet-deepblu.com/~eric/graphic_links/Gray.png

It's stupid and pointless quibbling over minutiae, pretending you cannot understand straightforward, uncomplicated concepts like "a group of freely interbreeding organisms."

I now doubt that you have any sort of test ( or concept even) for 'Can freely interbreed.'

Well, I doubt you have an honest bone in your body, so I suppose we're even then.

Why were Orcas said to be able to freely interbreed in the first place?

Gee, I don't know, Magellan. Maybe it's because they've been observed interbreeding.

Why do we think domestic dogs can "freely interbreed"? Why do we think humans can freely interbreed?

But maybe you do have a test to determine whether a group of individuals can freely interbreed.

Maybe I think you're arguing about how many angels can dance on the head of a pin.

If so - can we know what it is? It didn't work with Orcas. You seem pretty confident it (the mystery test) works with Chimps and Humans.

Well, Magellan: do you have any reason to think humans and chimps can interbreed? Maybe you won't be satisfied until someone actually tries it?

(God help the human who tries it with a chimp who isn't willing.)

You're toast, Magellan. When you're reduced to arguing that there's no way to tell whether or not any two organisms can interbreed, you know you're screwed.

For the longest time you were at least entertaining. Now that you're just droning on and on about how we can't tell if dogs and cats can or can't interbreed, I think I'd rather watch re-runs of Lost in Space.

magellan004

March 27th 2011, 02:05 AM

I do not get why Magellan persists in his mistaken belief that there has to be some member of one population with zero interfertility with any member of the other population which must, for some inexplicable reason, have had parents with 100% interfertility with all or even any members of the other population.

Can you give us some sort of line of reasoning why you think this is the case, Magellan? Because there is absolutely no reason I can see why any member of, say, population B which has zero interfertility with any member of population A has to have parents with any particular value of interfertility with respect to population A at all. Sure, at some point, there were lots of members of B which had very high interfertility with members of A. But why do you think it has to be true that some member of B with an interfertility with members of A of zero has to have parents with an interfertility with members of A which is even a fraction of one percent?

Maybe you've forgotten that there's no actual interbreeding going on between A and B?

It's logic.
Feel free to add to the alternatives-
1. An individual can freely interbreed with X.
2. An individual cannot freely interbreed with X.
3 ...

Unless you can think of a 3rd alternative then if a child can freely interbreed with X then either -
1. Its parents could freely interbreed with X (in which case speciation cannot happen) or
2. Its parents could not freely interbreed with X.

And vice-versa.
If a child cannot freely interbreed with X then either -
1. Its parents could freely interbreed with X or
2. Its parents could not freely interbreed with X (in which case speciation cannot happen).

There is just no other alternative.
I think this will help you think more clearly. You have defined species in terms of 'freely interbreeding'. Stick to that term. What you do is you slip into using 'interfertility' and fertility and that causes you to become lost in notions of 'partial interfertility' - which is an entirley different concept (and one which you refuse to define).

Either an individual can freely interbreed or they cannot freely interbreed.

Magellan

ericmurphy

March 27th 2011, 02:19 AM

It's logic.
There's no "logic" here at all.

Feel free to add to the alternatives-
1. An individual can freely interbreed with X.
2. An individual cannot freely interbreed with X.
3 ...

An individual from A can interbreed with 100% of the individuals in population B
An individual from A can interbreed with 99% of the individuals in population B
An individual from A can interbreed with 98% of the individuals in population B
An individual from A can interbreed with 97% of the individuals in population B
An individual from A can interbreed with 96% of the individuals in population B

Do I need to keep going, or do you get the idea?

Unless you can think of a 3rd alternative then if a child can freely interbreed with X then either -
I can think of thousands, millions of alternatives.

An individual from A can interbreed with 99.9% of the individuals in population B.
An individual from A can interbreed with 99.8% of the individuals in population B.
An individual from A can interbreed with 99.7% of the individuals in population B.
An individual from A can interbreed with 99.6% of the individuals in population B.
An individual from A can interbreed with 99.5% of the individuals in population B.

etc.

1. Its parents could freely interbreed with X (in which case speciation cannot happen)
Why can't it, Magellan? You seem to have forgotten that no interbreeding between A and B (leave it to you to use X, which refers to the original, ancestral population) is actually happening.

or
2. Its parents could not freely interbreed with X.

Its parents could have any level of interfertility with B, all the way from 100% to 0. What makes you think otherwise? What constrains the parents of any member of B to any particular level of interfertility with A?

And vice-versa.

Yes. Nothing constrains the interfertility of the parents of any member of A with respect to B, either.

If a child cannot freely interbreed with X then either -
1. Its parents could freely interbreed with X or
2. Its parents could not freely interbreed with X (in which case speciation cannot happen).

Wrong. Still the same problem:

http://www.planet-deepblu.com/~eric/graphic_links/GrayVsBandW.png

It is simply not the case that interfertility is either 100% or 0. No matter how many times you claim otherwise, it never changes.

There is just no other alternative.
There are nearly infinite alternatives.

I think this will help you think more clearly.
My thinking is just fine. Your thinking is like molasses mixed with Portland cement.

You have defined species in terms of 'freely interbreeding'. Stick to that term. What you do is you slip into using 'interfertility' and fertility and that causes you to become lost in notions of 'partial interfertility' - which is an entirley different concept (and one which you refuse to define).

There is no requirement that there be "freely interbreeding" between A and B. This has been pointed out to you over and over and over again. There is "freely interbreeding" within A and within B. Interfertility between A and B can take any value between 100% and 0.

Either an individual can freely interbreed or they cannot freely interbreed.

Wrong. Explain why it's impossible that a member of A could only interbreed with 50% of population B, or why the probability of viable offspring between A and B cannot be 20%, or 80%, or 33.333333%.

sylas

March 27th 2011, 02:59 AM

Either an individual can freely interbreed or they cannot freely interbreed.

That's not logic; that is merely an ongoing inability to recognize that in life, most things come in degrees, without sharp divisions. You are assuming a sharp division, where there is no such thing.

To say "either an individual is green, or it isn't green", is failing to get to grips with the notion that color varies along a continuous spectrum, and that there are many kinds of green. It doesn't mean that there's something illogical about being green, or that the notion itself is meaningless. It simply means that there's no sharp division between instances of "being green" and instances of "not being green". The attempt to give a completely precise definition of "green" would, in fact, fail to match reality. And yet, there are many things which certainly are green, and many others that definitely are not.

It is the same with identifying groups as species, or as "freely interbreeding populations", or identifying an individual, or a couple, as "fertile" or "sterile". These are all, in real life, qualities that can hold to varying degrees, with many instances that are plainly one or the other AND a range of instances that are in a gray area somewhere between.

It would be possible to give a precise definition which provides a strong yes and no answer to the question of whether or not a population is a freely interbreeding population; but that would only make things worse; by imposing an artificially sharp dividing line where in reality, no such line exists.

Be that as it may, there are two aspects to the notion of freely interbreeding.

First, it means that individuals in the group only breed with other individuals of the group. (That is, "interbreeding group").

Second, it means that the group does not contain smaller subgroups that are interbreeding. (That is, the breeding within the group occurs freely.)

Occasional examples of breeding from outside the group is not considered to be significant. This is a bit of a judgment call as to what is significant or not. It is, however, important to recognize that you CAN have small numbers of exceptions. HOW small is where you get the matter of degree. You can insist that the rules are universal. That is, there is no outbreeding whatsoever, and no smaller subgroup that is strictly inbreeding. But that would not be the definition as it is used and useful in biology. The real definition admits shades of gray, and this is how it should be.

Similarly, breeding preferences within the group don't actually upset the definition. For example, if you have racial varieties with a tendency to prefer to mate with members of their own race, this doesn't matter as long as the tendency is not so strong as to be almost universal. That word "almost" again is important, as a way of recognizing that the notion has shades of gray, cases that are not clearly one or the other. This is common with real life phenomena.

The issue with individuals who never mate at all is not a problem; they can be considered part of an interbreeding group as long as both their parents are in the group. Fussing over this detail is more inability to get past an unrealistic insistence on precision in a context where the biological reality is that there really are degrees, or shades of gray, in quality being described.

I continue to be pretty sure that this long running refusal to recognize shades of gray is deliberate. It sidetracks from substantive comment on the model itself. But in any case, whether the long running confusion is deliberate or not, it remains the case that comprehension of the models being described here will remain elusive until you are able to recognize that there are many useful concepts which admit real life cases that are ambiguous as instances of the concept or not.

Cheers -- sylas

Faid

March 27th 2011, 04:48 AM

That's what I thought we had agreed to - but every time I try to look at the steps involved in getting to 'two groups' Eric and Sylas introduce 'infertile individuals'.

So either infertile individuals count in the process or they don't.
That's what i am seeking to establish.
Can you have an sterile individual as one of a number of 'freely interbreeding individuals'?

If Eric says 'But that individual might be sterile therefore not able to interbreed ' then he has to exclude sterile individuals, and young, old, ill, those with a medical condition etc from his 'freely interbreeding' groups.

So - how do sterile individuals belong to a freely interbreeding group?

Any idea?

MagellanSure. And the egg is not part of the population of the chicken, and all that.

Can YOU explain why this nonsense matters to you, Mags?

Is it not the case that the sterile members do not leave descendants?

Faid

March 27th 2011, 05:38 AM

I doubt it.

Is that how relativity works in Magsworld? Interesting. Anyway, no help so far in getting an answer.

GObbledygook. First of all, the analogy is incorrect (because BOTH groups will change in time, as I told you). But even in that analogy: If the child is different from the parents, are the parents not different from the child?

Surely you can answer such a simple question?

It will achieve the almost impossible task of getting a straight answer from you. Do you have the necessary honesty and intellect to respond to this UNBELIEVABLY simple question, Mags? If not, well, you're no help (and beyond help).

Stand and deliver, Magsie.Still waiting, Mags.

Faid

March 27th 2011, 05:45 AM

Just so no one forgets, Mags has already clearly stated that he understands what exactly this loss of interbreeding refers to:
The silly thing is - this loss of capacity is in relation to Group A individuals which the Group B individuals have no contact with. So his latest attempts to equivocate and confuse the issue with interfertility within each group can be attributed to nothing other than dishonesty.

Big surprise, I know.

magellan004

March 27th 2011, 07:05 AM

Just so no one forgets, Mags has already clearly stated that he understands what exactly this loss of interbreeding refers to:So his latest attempts to equivocate and confuse the issue with interfertility within each group can be attributed to nothing other than dishonesty.

Big surprise, I know.

Your system relies on parents that can freely interbreed with As having a child that cannot freely interbreed with As.

For example Eric, who can freely interbreed with Aborigines (even though he nor his ancestors have ever had contact with aborigines) gives birth to a child that cannot freely interbreed with Aborigines.

That is the only way your system can work.

Find a fault - and by that I mean something more than 'I did that in Post 123'.

The alternative is that Eric keeps giving birth to children that can freely interbreed with Aborigines and Eric's descendants keep giving birth to children that can freely interbreed with Aborigines.

Magellan

magellan004

March 27th 2011, 07:22 AM

I looked back over some of the comments made by you, Sylas and Faid and I have isolated the cause of your problems. It all boils down to poor reasoning. The penny dropped in Post 1286 –

if you could answer this -
If one individual cannot interbreed with another individual are those two individuals members of the -
1. Same species
2. Different Species
3. Not known?

And you replied –
Based on a single piece of information, it's not known. If two individuals can interbreed, then by definition (the definition I have been using consistently) they are the same species. If they can't interbreed, then we need to know why. Is one of them sterile, for example?

But if we have an entire population of organisms no members of which can interbreed with another population of organisms, it's pretty safe to say those two populations are not the same species.
This just didn’t seem right. There was some sleight of hand going on so I sought assistance. Our trusty friends Modus Ponens and Modus Tollens came to hand.
Let’s have a look at a few examples of ‘definitions’.
1.
‘If a number is divisible by four it is an even number. ‘ There’s nothing wrong with that. It’s quite true. If a number is not divisible by four it might still be an even number. But there is something very wrong if that is given as a definition of an Even Number.
With the correct definition – ‘An even number is divisible by two ‘ then we can say ‘ ‘If the number is not divisible by two then the number is not even.’

Here’s another example –
2.
‘If a word (other than a pronoun) identifies any class of persons , places or things then it is a noun. We can happily conclude that if a word does not identify those things then the word is not a noun.
But to hold up this as a definition of Noun - 'A word that identifies any calls of persons.' is either misleading, sloppy or worse still , typical of what you have been doing – ‘A noun is a word that identifies a class of persons.’ Using that ‘definition’ we can’t make any conclusion about words that do not identify persons.

So back to the matter at hand –

If one individual cannot interbreed with another individual are those two individuals members of the -
1. Same species
2. Different Species
3. Not known?
If we had a definition of Species we would be able to answer either Yes or No.
What you have been doing is to try to ‘pass-off’ an example as a definition. You have no definition of Species. So therefore you actually have no way of identifying whether an organism is a member of a species. (How could you say that Four is an even number unless you knew what Even meant?) What you say you can do is identify some members of a Species. And you can’t even do that.
I know you take great pride in saying ‘Evolution predicts that we cannot define Species’. In science hypothesised things are measurable. Do you have a test that will yield a result ‘This individual is not a member of Species X’? If you can’t give a test then all individuals belong to Species X.

And you sprung yourself.
Magellan

magellan004

March 27th 2011, 07:29 AM

That's not logic; that is merely an ongoing inability to recognize that in life, most things come in degrees, without sharp divisions. You are assuming a sharp division, where there is no such thing.

There is such a thing.
A thing is either A or Not A.
That is the basis of all scientific knowledge.
This is a fundamental truth - 'Either an individual can freely interbreed or they cannot freely interbreed.'

You do not have any discretion to mess with that. I am not assuming anything when I say that (except the axiom 'A or NOT A').

Look at poor Eric -

What other alternative is there?
1. An individual can freely interbreed with X.
2. An individual cannot freely interbreed with X.
3 ...

An individual from A can interbreed with 100% of the individuals in population B

He totally lost all reason. He has to construct a fantasy to explain his model - ie - that the question was not about 'Freely interbreeding with X.'
He invents a new 'reality' and it becomes my problem. He cannot come to terms with his own problem.

So have you.

You have constructed a model that does not accord with observation and then you cite observation to defend your model.

That is not a reasoned argument.

That the observed state of nature conflicts with your model is YOUR problem - not reality's and not mine.

It is the same with identifying groups as species, or as "freely interbreeding populations", or identifying an individual, or a couple, as "fertile" or "sterile". These are all, in real life, qualities that can hold to varying degrees, with many instances that are plainly one or the other AND a range of instances that are in a gray area somewhere between.

If 'Freely interbreeding ' does not hold as a classification in reality then that is not my deficiency - it is a deficiency of your model. Your model is based on 'Freely interbreeding.'

In real life we do not see 'freely interbreeding groups of individuals'. It was YOU that suggested that as the basis of your Speciation process. I did not suggest it. 'Freely interbreeding' does not accord with observation.

You observe a state of nature where no group of individuals can 'freely interbreed'. You devise a model based on 'freely interbreeding' definitions, processes and criteria to explain the observed state of nature. I question how your model works and you try to lump the reality test on to me. You say 'There's no such thing as 'freely interbreeding' and I should not expect to see such.

Your model is based on a notion of 'This is a group of individuals that cannot freely interbreed with X and once could ' . You have to demonstrate how that came about. That means you have to show that there could have been a child that could not freely interbreed with X who had parents that could freely interbreed with X.

IF two parents that can freely interbreed with X have a child then that child can be one of only two things –
1. Freely interbreed with X or
2. Not freely interbreed with X.
If 2. applies then you have to explain how it’s possible.

An individual can either freely interbreed with X or cannot freely interbreed with X. That is non-negotiable.

Let me give you an analogy –

Sylas – ‘All motor cars start out being built by Toyota from Toyota components and end up in Toyota , Ford or other manufactures’ factories.’

Magellan – ‘If that were true then we should expect to see the first Ford component added to a Toyota base.’

Eric – ‘There is no reason to think that Ford Components must be added to a Toyota base. There are shades of grey. Some components are 80% Ford, some are 70% Ford.

Sylas – ‘Cars are made up of thousands of parts. There is no stage at which a car becomes a Ford Car or ceases to be a Toyota car’.

Magellan – ‘A component is either a Ford component or a Toyota component.. IF you define a Toyota as a car with only Toyota parts then a car with a Ford part is not a Toyota.’

Eric - ‘Some Toyota cars do have Ford components.’

Sylas – ‘ That is not how it works in reality. Cars are made up of all different components. You should not expect to see ‘Ford components ‘ and ‘Non-Ford components’. That is Binary thinking. That is not how it works in reality.’

Eric – ‘Here’s a graph of how it works. A car starts out being All Toyota. In the intermediate stages it is neither a Toyota car nor a Ford Car. In the end it is a Ford car.’

Magellan – ‘According to your model there must be a point at which a Ford component is added to a Toyota base.’

Sylas – ‘We have told you repeatedly that there is no such thing as a completely Toyota car nor a completely Ford car. We don’t see that in reality. In reality all cars have all sorts of manufacturers’ components.’

Magellan – ‘ How do you know what a Toyota car is?’

Eric ‘Anyone with half a brain can identify a Toyota car.

Magellan – ‘Can we identify whether a car is not a Toyota ?’

Eric ‘We would need further information. It may be that the car had a factory fault. That would not mean the car is not a Toyota car. ‘

Magellan – ‘So how do you identify a Ford car?’

Eric - ‘Any idot can identify a Ford car.’

Sylas - ‘Your question about whether this car is either a Ford car or a Toyota car leads me to wonder whether you are trolling. The manufacturing process involves Toyota cars gradually becoming Ford cars or Toyota cars. We cannot expect to identify whether one car is a Ford car until it becomes a Ford car. We only know whether all cars from a factory are Ford cars. I have found some articles on how difficult it is to identify whether a car comes from a Ford factory or a Toyota factory.

Magellan

sylas

March 27th 2011, 08:25 AM

There is such a thing.
A thing is either A or Not A.
That is the basis of all scientific knowledge.
This is a fundamental truth - 'Either an individual can freely interbreed or they cannot freely interbreed.'

Of course, we already know for a fact that this is not so. Some couples have children freely. Others have to work at it. And some cannot have children at all. We also know this same thing generalizes to populations -- because it is directly observed. Some sets of organisms interbreed freely; others show assortative mating, to varying degrees, which in the extreme cases becomes a set of organisms partitioned into subgrounps with no freedom at all for formation of hybrids.

Your insistence on using strict binary classifications is not only a failure to understand science and a failure to deal with the models of speciation used in science. It is a failure to see the reality under your very nose that science is required to represent.

When you learn to deal with it as well, then you will deal better with science, and with the models used in science.

You CAN of course, try to see fertility (for example) simply in terms of "able to have children" and "not able to have children". Not very useful at a fertility clinic or in a scientific study of fertility; it obscures essential aspects of fertility which are needed to really understand how it works. Same with models of speciation. To understand models of speciation, you really and truly do need to understand the intermediate steps along the way, which are somewhere on a spectrum between clear speciation into distinct species, fully free interbreeding within a single species, and a species which is only partially sorted into incipient species. The binary classification obscures the processes which are explained by the model.

Cheers -- sylas

Faid

March 27th 2011, 09:58 AM

Your system relies on parents that can freely interbreed with As having a child that cannot freely interbreed with As. Sure, if by "not freely interbreed" you mean "less easy to interbreed". But of course, you'll just try to pretend that means going from 100% interbreeding to 0% interbreeding. You're nothing if not predictable.

For example Eric, who can freely interbreed with Aborigines (even though he nor his ancestors have ever had contact with aborigines) gives birth to a child that cannot freely interbreed with Aborigines.

That is the only way your system can work.See above. There is a decrease in interbreeding capacity. That decrease takes thousands and thousands and generations to go from 100% to 0%. In any single generation, the decrease is hardly detectable.

Find a fault - and by that I mean something more than 'I did that in Post 123'.No need to 'find a fault' in anything. I already told you that we are not dealing with an "all-or-nothing" approach to interbreeding capacity. The fact that YOU keep ignoring that explanation shows that YOU cannot find any fault with it, and prefer to pretend you "missed" it.

The alternative is that Eric keeps giving birth to children that can freely interbreed with Aborigines and Eric's descendants keep giving birth to children that can freely interbreed with Aborigines.Hogwash. Let me offer the explanation once again, so that you won't seek refuge in your inability or boredom and refuse to read my previous posts:

From generation to generation, he interbreeding capacity with the other group keeps decreasing. If by "freely" you mean 100% capacity, that capacity may only be slightly smaller in one generation, but after thousands and thousands of generations, it's a very different story. The accumulated decrease eventually drops to zero.

It's a very simple concept. If YOU think you can "find fault" with that explanation, Mags, please do. But stop ignoring it: It just helps in demonstrating your desperation.

Faid

March 27th 2011, 10:08 AM

I looked back over some of the comments made by you, Sylas and Faid and I have isolated the cause of your problems. It all boils down to poor reasoning. The penny dropped in Post 1286 –

And you replied –
This just didn’t seem right. There was some sleight of hand going on so I sought assistance. Our trusty friends Modus Ponens and Modus Tollens came to hand.
Let’s have a look at a few examples of ‘definitions’.
1.
‘If a number is divisible by four it is an even number. ‘ There’s nothing wrong with that. It’s quite true. If a number is not divisible by four it might still be an even number. But there is something very wrong if that is given as a definition of an Even Number.
With the correct definition – ‘An even number is divisible by two ‘ then we can say ‘ ‘If the number is not divisible by two then the number is not even.’

Here’s another example –
2.
‘If a word (other than a pronoun) identifies any class of persons , places or things then it is a noun. We can happily conclude that if a word does not identify those things then the word is not a noun.
But to hold up this as a definition of Noun - 'A word that identifies any calls of persons.' is either misleading, sloppy or worse still , typical of what you have been doing – ‘A noun is a word that identifies a class of persons.’ Using that ‘definition’ we can’t make any conclusion about words that do not identify persons.

So back to the matter at hand –

If one individual cannot interbreed with another individual are those two individuals members of the -
1. Same species
2. Different Species
3. Not known?
If we had a definition of Species we would be able to answer either Yes or No.
What you have been doing is to try to ‘pass-off’ an example as a definition. You have no definition of Species. So therefore you actually have no way of identifying whether an organism is a member of a species. (How could you say that Four is an even number unless you knew what Even meant?) What you say you can do is identify some members of a Species. And you can’t even do that.
I know you take great pride in saying ‘Evolution predicts that we cannot define Species’. In science hypothesised things are measurable. Do you have a test that will yield a result ‘This individual is not a member of Species X’? If you can’t give a test then all individuals belong to Species X.

And you sprung yourself.
Magellan

^^^^^ LOL. Did I call it, or did I call it? As predicted, Mags tries to pretend that those definitions are conditional statements, and that the defining properties are nothing more than side-effects or implications.

Like I said Mags: You're nothing if not predictable, especially when you get desperate.

ericmurphy

March 27th 2011, 10:25 AM

Your system relies on parents that can freely interbreed with As having a child that cannot freely interbreed with As.

Wow. You really are unteachable, aren't you? Sylas just did a big long post showing exactly why this stupidity is utterly wrong, right after the post I did that also shows how utterly wrong it is.

There is no requirement in my model that any organism in B which cannot interbreed with A have parents that can interbreed with A. It simply doesn't exist, and your endless, mindless repetition of your claim that there is doesn't make it any more true.

For example Eric, who can freely interbreed with Aborigines (even though he nor his ancestors have ever had contact with aborigines) gives birth to a child that cannot freely interbreed with Aborigines.

Where is the requirement that this happen, Magellan?

That is the only way your system can work.

No it's not. There's no reason at all why an organism which cannot interbreed with members of the other population have parents which can. All that is required is that it had ancestors which could. Possibly distant ancestors.

Instead of just repeating your claim, can you actually construct an argument that shows why you think your claim is correct? Seriously, Magellan; I'm interested to see what your thinking is. I've already explained why it's wrong, but you haven't even tried to show why it's right.

Find a fault - and by that I mean something more than 'I did that in Post 123'.

I already did. A member of population A which has zero interfertility with any member of B could have parents which had 1% interfertility with B. Now explain why you think that's impossible.

The alternative is that Eric keeps giving birth to children that can freely interbreed with Aborigines and Eric's descendants keep giving birth to children that can freely interbreed with Aborigines.

Why? Why is that alternative, Magellan? Why can't it be the case that every generation of Eric's descendants has lower and lower interfertility with Aborigines? Why is that impossible?

ericmurphy

March 27th 2011, 10:35 AM

I looked back over some of the comments made by you, Sylas and Faid and I have isolated the cause of your problems.
I'm not the one with the problems, Magellan.

It all boils down to poor reasoning. The penny dropped in Post 1286 –

I'm not the one with the poor reasoning, Magellan.

And you replied –
This just didn’t seem right. There was some sleight of hand going on so I sought assistance. Our trusty friends Modus Ponens and Modus Tollens came to hand.
Let’s have a look at a few examples of ‘definitions’.
1.
‘If a number is divisible by four it is an even number. ‘ There’s nothing wrong with that. It’s quite true. If a number is not divisible by four it might still be an even number. But there is something very wrong if that is given as a definition of an Even Number.
With the correct definition – ‘An even number is divisible by two ‘ then we can say ‘ ‘If the number is not divisible by two then the number is not even.’

Here’s another example –
2.
‘If a word (other than a pronoun) identifies any class of persons , places or things then it is a noun. We can happily conclude that if a word does not identify those things then the word is not a noun.
But to hold up this as a definition of Noun - 'A word that identifies any calls of persons.' is either misleading, sloppy or worse still , typical of what you have been doing – ‘A noun is a word that identifies a class of persons.’ Using that ‘definition’ we can’t make any conclusion about words that do not identify persons.

So back to the matter at hand –

If one individual cannot interbreed with another individual are those two individuals members of the -
1. Same species
2. Different Species
3. Not known?
If we had a definition of Species we would be able to answer either Yes or No.
Here's the sloppy reasoning, Magellan, and it's not mine: despite the fact that you have been told over and over again that there are inherent ambiguities in the definition of species—that it is a PREDICTION of evolutionary theory that there will be inherent ambiguities—you continue to insist on a precise, rigorous definition of the term. There is no such definition, and your endless insistence that we provide you one demonstrates your inability to think clearly or to understand simple concepts.

We are not the ones with the "sloppy thinking." YOU ARE.

What you have been doing is to try to ‘pass-off’ an example as a definition. You have no definition of Species.
Utterly false. I've given you my operational definition of the term a million times in this thread, and that definition is workable for the purposes we are putting it to.

So therefore you actually have no way of identifying whether an organism is a member of a species. (How could you say that Four is an even number unless you knew what Even meant?)

Then why is it, Magellan, that I can say for a 100% certainty that all humans are the same species? Why can I say with 100% certainty that German shepherds and Australian shepherds are the same species? Why can I say with 100% certainty that Great Danes and Siamese cats are NOT the same species?

Seems like you're kind of wrong, doesn't it? Just because there are edge cases where the matter is not so clearcut—which, again, is a freaking PREDICTION of evolutionary theory—does not change that simple fact.

Your idiot claim that we can never tell whether two organisms are or are not the same species is idiotic. Please drop it.

What you say you can do is identify some members of a Species. And you can’t even do that.

You say that, despite the fact that I just did?

I know you take great pride in saying ‘Evolution predicts that we cannot define Species’.
I have never said that. It's the same old problem:

http://www.planet-deepblu.com/~eric/graphic_links/GrayVsBandW.png

In science hypothesised things are measurable.
Nope. As sylas points out, you can't just say "these objects are green, and these objects are not green."

Do you have a test that will yield a result ‘This individual is not a member of Species X’? If you can’t give a test then all individuals belong to Species X.

What about "sometimes it cannot be said for certain that two individuals are or are not the same species" can't you get? What about "these two organisms are definitely the same species" can't you get? What about "these two organisms are definitely not the same species" can't you get?

ericmurphy

March 27th 2011, 10:40 AM

There is such a thing.
A thing is either A or Not A.
That is the basis of all scientific knowledge.
This is a fundamental truth - 'Either an individual can freely interbreed or they cannot freely interbreed.'

Come on, Magellan, are you really this dense? Do you really believe that EVERYTHING is either A or not A?

Is it definitely true that it is always "hot" or "not hot"? What's your definition of hot? Anything more than 30°C is "hot" and everything cooler is "not hot"? I live in San Francisco, Magellan. Do you think my definition of a "hot day" is the same as yours?

You do not have any discretion to mess with that. I am not assuming anything when I say that (except the axiom 'A or NOT A').

You have a seriously broken idea of how the world works, Magellan. This is a serious problem for you:

http://www.planet-deepblu.com/~eric/graphic_links/GrayVsBandW.png

Look at poor Eric -

He totally lost all reason. He has to construct a fantasy to explain his model - ie - that the question was not about 'Freely interbreeding with X.'
He invents a new 'reality' and it becomes my problem. He cannot come to terms with his own problem.

It's not a "problem" for me that fertility can take values between 100% and zero. It's a problem for you.

So have you.

You have constructed a model that does not accord with observation and then you cite observation to defend your model.

Magellan, if it were true that fertility is always 100% or zero, then why do some women have a harder time having children then others?

When you can answer this question, the rest of your post will be worth responding to.

ericmurphy

March 27th 2011, 10:42 AM

And Magellan still can't say what is wrong with this graph:

http://www.planet-deepblu.com/~eric/graphic_links/SpeciesCurve.png

He still can't say why such a curve is impossible. Instead, he argues about what "majority" means, and insists that it can only and ever mean "50.000000000000000001%."

He knows he doesn't have an argument. He's just trying to run out the clock. The problem is, there is no bell that can save him.

ericmurphy

March 27th 2011, 10:46 AM

And by the way, Magellan: just editing my diagram to remove the orange region doesn't show that speciation is impossible, nor does it show that interfertility cannot have any value other than 100% or zero. Even your own poorly-drawn curve still shows interfertility to take values between 100% and zero. You just redefined membership in a species to include members who have 50.0000000000000001% interfertility with the other population.

As usual, you're just quibbling over terminology. You still cannot address my model. You've given up even trying.

ericmurphy

March 27th 2011, 10:54 AM

One more comment this morning before I get rained on for five hours on my bike ride.

It is often said of RWAs that they see everything in black-and-white terms. GWB's statement that he "doesn't do nuance" is a classic example. There's a certain creationist Faid and I used to debate all the time who was notorious for mistaking "some" for "all" or or "few" for "none." But Magellan is the most pathological case I have ever seen. It really does seem like he simply cannot imagine a particular variable taking on a range of values. It's like he literally cannot imagine a situation where fertility can either be total or zero, despite the fact that we have given him innumerable examples from day-to-day life that demonstrate conclusively that he's wrong about that.

If fertility were always 100% or zero, then why is it the case that some women get pregnant even while on birth control pills, whereas other women can try for years and years unsuccessfully to have children, only to eventually successfully carry a child to term, Maegllan?

How is that possible in your world?

Faid

March 27th 2011, 02:55 PM

Predicted response by Mags: "Gee, I have no idea, so just wait while I completely ignore your point, dig up some other post from all the ones I haven't addressed and respond to that, hoping to divert the discussion"

ericmurphy

March 27th 2011, 05:38 PM

Magellan claims it's impossible for interfertility to be anything but 100% or zero. We already know this isn't true, because we see it in human populations. But sylas provided, in his post 1284, a plausible mechanism for how it can happen in two reproductively-isolated populations which are undergoing speciation.

Take a mutation in A which completely prevents interbreeding with population B (but has no effect on interfertility with members of A; sylas's post gave a hypothetical example of such a mutation). Initially, the mutation might appear in a single member of A. At this point, even if up to now every single member of B could interbreed with every single member of A, that's no longer the case. There is now a member of A with which no member of B can interbreed.

What does that make the interfertility rate between A and B? Obviously that depends on the size of the population, but let's say the population of A is 10,000 individuals. That makes the interfertility rate 99.99%. Not 100%, and not zero.

Let's say that this particular mutation starts to spread throughout A, either because it confers an adaptive benefit in the environment A is in, because it is linked with some other mutation that provides such a benefit, or simply through neutral drift with no selection pressure at all. At some point, this mutation might be present in 5,000 individuals, or 50% of A.

What's the interfertility rate between A and B, Magellan? It's 50%, isn't it?

Later on, the mutation might go to fixation, meaning it appears in all members of A. What's the interfertility rate now, Magellan?

it's 0, isn't it?

What was it, again, that you said prevented interfertility rates from being anything other than 100% or 0? Oh, right; you never did say what prevented it.

You just said it couldn't be anything but 100% or 0.

magellan004

March 27th 2011, 05:46 PM

sylas

March 27th 2011, 06:08 PM

How do you calculate Fertility of -
1. An individual,
2. A group.
Tell me what your formulae are.

Eric's model is a general framework; not a concrete simulation.

You can, however, ask this question of me, because I DO have a concrete simulation.

The answer is as follows.

Let fertility(X, Y) be any function which returns the probability of successful mating given two individuals X and Y. If can be continuous, giving values anywhere in the range 0 to 1, or (more simply but less realistically) it may be discrete, returning only values 0 or 1, with nothing in between.

Given this relation for pairs of individuals, extend it to sets of individuals as follows.

for sets of individuals A and B, define fertility(A,B) to be:
http://rogercortesi.com/eqn/tempimagedir/eqn7368.png

For a single individual x, and a set of individuals B, let Bx denote the subset of B obtained by removing anything that is not a sexually mature adult of opposite gender to x.

Then the fertility of an individual X within a set B is defined to be f({x}, Bx)

This gives a value in the range 0 to 1, even if we limit ourselves to a highly simplified notion of fertility for a mated couple as being either 0% or 100% with nothing in between.

Note that it is standard for fertility of an an individual to differ when obtained with respect to different sets of prospective partners.

Cheers -- sylas

magellan004

March 27th 2011, 06:11 PM

Take a mutation in A which completely prevents interbreeding with population B (but has no effect on interfertility with members of A; sylas's post gave a hypothetical example of such a mutation). Initially, the mutation might appear in a single member of A. At this point, even if up to now every single member of B could interbreed with every single member of A, that's no longer the case. There is now a member of A with which no member of B can interbreed.

After a bit of editing this becomes -

(Edited by Magellan)Take a mutation in Group B that starts with one child of Parent members of B. The parents can freely interbreed with individuals in Group A. The mutation in the first child in Group B completely prevents interbreeding with individuals in Group A ( Ed. See note *). Initially, the mutation MUST appear in a single member of A. At this point, every single member of B could interbreed with every single member of A, that's no longer the case. There is now a member of B with which no member of A can interbreed.

WOW! We got there!
I've switched your 'A' and 'B' around to match previous discussions. I also removed '(but has no effect on interfertility with members of B)' from * because that is yet to be established.

Now all you have to work out is if it's possible that Group B ends up with only these special types of individuals that cannot breed with individuals in Group A.

For ease of typing call any individual with the mutation a 'Group B X type'. Call any member of Group B that does not have the mutation in their family line a 'Group B Non-X type.'

Can we /how do we end up with only Group B X types and Group As in the one physical location (with no Group B Non-X types)?

Magellan

rogue06

March 27th 2011, 06:16 PM

Magellan claims it's impossible for interfertility to be anything but 100% or zero. We already know this isn't true, because we see it in human populations.
I wonder if m004 has ever heard of fertility clinics and if so questioned why they exist.

magellan004

March 27th 2011, 06:27 PM

ericmurphy

March 27th 2011, 08:19 PM

How do you calculate Fertility of -
1. An individual,
It's just the probability of an organism having offspring, Magellan. How hard is it? You take the number of successful productions of offspring, and divide by the number of attempts?

Seriously, this isn't rocket science.

2. A group.
Tell me what your formulae are.

The same way.

An alternative measure would be to determine what percentage of group B an individual in group A can produce offspring with. Divide by the total number of individuals in group A.

There are numerous other ways you can figure it out, depending on exactly what you want to find out. You could compare the number of successful matings in A-A pairings, and compare them to A-B pairings, and see what the proportion is. I'm sure there are other ways, as well.

Seriously, this isn't rocket science.

Well, maybe it is. For you.

But what difference does it make, Magellan? We've already given you multiple scenarios where interfertility is a number less than 100% and greater than 0. But what's even worse for you is that even if it were true that interfertility can only be 100% or zero, we still get speciation. Remember this diagram?

http://www.planet-deepblu.com/~eric/graphic_links/FirstNonInterfertileLine.png

So why are you wasting a time making an unwinnable argument? Even if you were right (and you're not) you still get speciation.

You can't stop the future, Magellan.

ericmurphy

March 27th 2011, 08:28 PM

After a bit of editing this becomes -

WOW! We got there!
Magellan, we already got there. Remember this diagram?

http://www.planet-deepblu.com/~eric/graphic_links/FirstNonInterfertileLine.png

We got there a long time ago, and you know what? Getting there did you exactly no good. We still get speciation. Not that any mutation has to arise only once initially, especially in large populations. The same mutation might arise multiple times, even within one generation, let alone in successful generations. But even if it does arise once, it doesn't matter, because you still get speciation.

I've switched your 'A' and 'B' around to match previous discussions.
Further evidence of your cluelessness. Which one is A and which is B is utterly irrelevant.

I also removed '(but has no effect on interfertility with members of B)' from * because that is yet to be established.

No it doesn't. It's a stipulated condition. It's part of the model, Magellan, and the only way you can get it out of the model would be demonstrate rigorously that no such mutation is possible, which you cannot do.

So live with it.

Now all you have to work out is if it's possible that Group B ends up with only these special types of individuals that cannot breed with individuals in Group A.

Nothing has to happen in B at all. If the mutation which bars interfertility in A goes to fixation, then we're done. Speciation.

For ease of typing call any individual with the mutation a 'Group B X type'. Call any member of Group B that does not have the mutation in their family line a 'Group B Non-X type.'

Can we /how do we end up with only Group B X types and Group As in the one physical location (with no Group B Non-X types)?

Simple. The mutation goes to fixation, either due to selection pressures or even just due to neutral drift. If you'd actually read sylas's post where he explains how this happens—and understood it—you'd already know this.

ericmurphy

March 27th 2011, 08:30 PM

I wonder if m004 has ever heard of fertility clinics and if so questioned why they exist.

Magellan already knows he's screwed on this issue, which is why he never even acknowledges, let alone answers, questions like what the purpose of fertility clinics might be or how it can be the case that some women have to fight tooth and nail to avoid getting pregnant while other women work and work and work for years on getting pregnant.

Magellan is many things, but honest isn't one of them.

ericmurphy

March 27th 2011, 08:32 PM

Hopefully we will now be able to sort this out.

http://www.theologyweb.com/campus/attachment.php?attachmentid=65530&d=1301264812

Magellan

The part of my diagram you removed shows how we get there. so I put it back in:

http://www.planet-deepblu.com/~eric/graphic_links/SpeciesCurve.png

ericmurphy

March 27th 2011, 08:39 PM

And if you don't like that answer, there's always this one:

Yes. And here's how:

We start with a single, freely-interbreeding ancestral population X. All members of this population can interbreed with each other.
At some point, some event or process divides X into two freely-interbreeding subpopulations, A and B. At the time of initial separation, all members of A and B are interfertile not only with other members of their own population but also with members of the other population, and would be interfertile with members of X if there still were any.
The isolating event or process could be geographic isolation due to a new mountain range forming, climate change forming a barrier between two regions, migration patterns reducing or eliminating gene flow between remote areas inhabited by the original population, or colonization of an island by either subpopulation.

http://www.planet-deepblu.com/~eric/graphic_links/Isolation.png

Over time, genetic differences in both populations accumulate, so that the members of each population become increasingly different from members of the other population (but selective pressures minimize the differences within a population).
http://www.planet-deepblu.com/~eric/graphic_links/GeneticDriftV2.png

As those differences accumulate, interfertility between populations (if there were any interbreeding between them, which there isn't) slowly declines over time. Again, selective pressures keep interfertility within a population from declining.
http://www.planet-deepblu.com/~eric/graphic_links/InterfertilityVsDifferences.png
After sufficient genetic differences have accumulated, interfertility between A and B declines to zero. At this point, we have two separate species which cannot interbreed.
http://www.planet-deepblu.com/~eric/graphic_links/SpeciesCurve.png
Even if further events allow an overlap of territories between A and B, they will no longer be able to interbreed, and will remain separate species indefinitely.
http://www.planet-deepblu.com/~eric/graphic_links/Interbreeding.png
As time goes on, both A and B may undergo additional speciation events, similar to the above, with both A and B taking the place of X in the sequence of events.

magellan004

March 27th 2011, 09:17 PM

Of course, we already know for a fact that this is not so. Some couples have children freely. Others have to work at it. And some cannot have children at all. We also know this same thing generalizes to populations -- because it is directly observed. Some sets of organisms interbreed freely; others show assortative mating, to varying degrees, which in the extreme cases becomes a set of organisms partitioned into subgrounps with no freedom at all for formation of hybrids.

Your insistence on using strict binary classifications is not only a failure to understand science and a failure to deal with the models of speciation used in science. It is a failure to see the reality under your very nose that science is required to represent.

When you learn to deal with it as well, then you will deal better with science, and with the models used in science.

You CAN of course, try to see fertility (for example) simply in terms of "able to have children" and "not able to have children". Not very useful at a fertility clinic or in a scientific study of fertility; it obscures essential aspects of fertility which are needed to really understand how it works. Same with models of speciation. To understand models of speciation, you really and truly do need to understand the intermediate steps along the way, which are somewhere on a spectrum between clear speciation into distinct species, fully free interbreeding within a single species, and a species which is only partially sorted into incipient species. The binary classification obscures the processes which are explained by the model.

Cheers -- sylas

To use Evo-Jargon, if a Group B child was born with a difference/mutation that allowed that child to interbreed with Group A individuals 'sometimes' and that difference became 'fixed' (whatever that means) then the end result is Group B individuals and Group A individuals could mate and have children sometimes.

You have been emphatic that that is not what evolution says happens. Humans and Chimps don't mate sometimes.

The 100% / 0% fertility thing is purely a concocction of evolution, not me.

Magellan

magellan004

March 27th 2011, 09:25 PM

magellan004

March 27th 2011, 09:29 PM

It's just the probability of an organism having offspring, Magellan. How hard is it? You take the number of successful productions of offspring, and divide by the number of attempts?

Seriously, this isn't rocket science.

The same way.

An alternative measure would be to determine what percentage of group B an individual in group A can produce offspring with. Divide by the total number of individuals in group A.

There are numerous other ways you can figure it out, depending on exactly what you want to find out. You could compare the number of successful matings in A-A pairings, and compare them to A-B pairings, and see what the proportion is. I'm sure there are other ways, as well.

Seriously, this isn't rocket science.

Well, maybe it is. For you.

But what difference does it make, Magellan? We've already given you multiple scenarios where interfertility is a number less than 100% and greater than 0. But what's even worse for you is that even if it were true that interfertility can only be 100% or zero, we still get speciation. Remember this diagram?

http://www.planet-deepblu.com/~eric/graphic_links/FirstNonInterfertileLine.png

So why are you wasting a time making an unwinnable argument? Even if you were right (and you're not) you still get speciation.

You can't stop the future, Magellan.

Why do you think drawing a graph = It is possible?

Magellan

ericmurphy

March 27th 2011, 09:50 PM

To use Evo-Jargon, if a Group B child was born with a difference/mutation that allowed that child to interbreed with Group A individuals 'sometimes' and that difference became 'fixed' (whatever that means)
it means every member of the population has it. Seriously, Magellan: how are you going to frame a coherent criticism of evolutionary theory if you don't even know what it is?

then the end result is Group B individuals and Group A individuals could mate and have children sometimes.

So what? They're not interbreeding anyway! And as I've said to you before, there are many, many, many ways two genomes can be different, and only one way they can be the same. The chances that two genomes will diverge to the point where interbreeding is impossible is infinitely higher than that they will converge to the point where previously-impossible interbreeding became possible.

Speciation, like diamonds, is forever.

You have been emphatic that that is not what evolution says happens. Humans and Chimps don't mate sometimes.

They don't mate at all, Magellan. Or, if they did, no offspring would result.

The 100% / 0% fertility thing is purely a concocction of evolution, not me.

Uh, no. Once again, you're making claims about evolutionary theory that are demonstrably false. Evolutionary theory doesn't say fertility must be 100% or 0. YOU do.

But if you're now saying you don't think it's true that it must be 100% or 0, I'll be happy to take that as your concession on a point that never did you any good anyway.

ericmurphy

March 27th 2011, 09:52 PM

Why do you think drawing a graph = It is possible?

Magellan

I don't. That's why there's an explanation to go with the pretty pictures, Magellan.

And since you can't find anything wrong with either the pretty pictures or the explanation, I'm going to keep on thinking speciation is possible, unless and until you can give me a reason to think otherwise. So far you've been an abject failure at giving me a reason to think otherwise.

ericmurphy

March 27th 2011, 11:02 PM

So far, Magellan hasn't even managed to put a scratch in my model. He can't tell me why we can't start with a single species. He can't tell me why we can't split that original species into two separate populations. He can't tell me why those two populations can't drift apart from each other genetically. He can't tell me why as they drift further and further apart, they become less and less able to interbreed (or would be, if there were actually any interbreeding happening). He can't tell me why they can't eventually become completely unable to interbreed, even if they end up in the same environment. And he can't tell me why, at the end of this process, we don't end up with two different species where there used to be only one.

And he can't tell me why that doesn't amount to speciation.

After 91 pages: no progress.

magellan004

March 28th 2011, 12:31 AM

sylas

March 28th 2011, 12:32 AM

As promised, I have now uploaded and made available a simple simulation program which captures the ideas expressed in this thread for models of speciation. Many of the things Eric has been describing can be seen to appear spontaneously in the program -- not as a result of my programming them to appear, but as a consequence of the model of speciation being expressed in the simulation.

Many of the concrete questions about definitions and so on can be answered very precisely and unambiguously with respect to this particular simulation program; and then people may contrast and or compare that with any analogues in real biology. I hope this will ground discussion better.

Seeing how this thread has been progressing, I have established some ground rules in the new thread that might help maintain focus. Probably everyone involved here will be able to see how I am restricting the posting behaviours of the people they are debating. All are welcome in the new thread, but please do respect the requests I have made in the initial post.

They are as follows...

Please don't post material simply denigrating another person. Speculating what they might answer, or complaining about them being slow on the uptake or trolling or whatever, is not welcome.
No sarcasm.
Please don't make multiple successive posts. Decide what you want to add to the discussion, and then post. If you want to reply to multiple prior posts, you can do this within a single post.
Please keep on the topic of speciation and simulations of speciation.

These requests are intended to help everyone engage more productively, so if you think there is genuinely a useful reason for violating one of them (especially for the one on successive posts), go ahead. I'll ask moderators to help us prune things if it gets out of hand. If you want to join in, be welcome. Just try to keep in the intended spirit you think I am aiming for, and we'll see how it goes!

The code and the executable and transcripts can be downloaded at from links at the new thread. See Simulation of Speciation

One thing I hope to try is automatic generation of graphs corresponding to what Eric has given here. I have not done this yet; but I hypothesize that they'll have about the same shape, though not as nice and smooth. Might take me a while, but it's something I'm considering.

I expect (and I hope) I will be posting more in the new thread now, rather than in this one.

Cheers -- sylas

magellan004

March 28th 2011, 12:38 AM

I don't. That's why there's an explanation to go with the pretty pictures, Magellan.

And since you can't find anything wrong with either the pretty pictures or the explanation, I'm going to keep on thinking speciation is possible, unless and until you can give me a reason to think otherwise. So far you've been an abject failure at giving me a reason to think otherwise.

It's taken you this long to get to step 1 - Two parents give birth to a child that cannot breed with any member of Group A. SO by Page 180 we hopefully will be tackling Step 2. And personally I think it's wonderful to progress.

Magellan

ericmurphy

March 28th 2011, 12:44 AM

Is it possible for a child of (say) yours to be born that can breed with Chimps?

Nope.

That might give you an idea of the scope of the issues we are facing.

Why? Why on earth would you think that, Magellan? Humans and chimps differ by something like 30 million base pairs. What, you think somehow random mutations are somehow going to get a human being, in one generation, to go back to a genome interfertile with chimps? Without more or less looking like a chimp?

It's like you're making negative progress. First, you want us to believe you can go from 100% interfertility to 0 in a single generation, and now, even more implausibly, you want us to believe you can go from 0 to 100% interfertility in a generation.

Which is easier? To drop a china teacup on the ground and have it break into a few hundred pieces? Or to sweep up all those pieces, drop them on the floor, and expect a teacup to form?

I think you know less about how evolutionary theory works now than you did a year and a half ago. How is that possible?

ericmurphy

March 28th 2011, 12:49 AM

It's taken you this long to get to step 1 - Two parents give birth to a child that cannot breed with any member of Group A. SO by Page 180 we hopefully will be tackling Step 2. And personally I think it's wonderful to progress.

Magellan, I talked about interfertility going from 100% to 0 in a single generation about four hundred posts ago. Remember this?

http://www.planet-deepblu.com/~eric/graphic_links/FirstNonInterfertileLine.png

And it did your "arguments" exactly no good. I showed how speciation would happen just as easily in a situation where interfertility goes from 100% to zero in a single generation.

Since step 1 didn't even put a scratch in my model, there's no reason to think any other step will put a scratch in it. What, you're going to argue it's impossible for a species to be split into two populations which don't interbreed?

magellan004

March 28th 2011, 01:20 AM

Nope.

Why? Why on earth would you think that, Magellan? Humans and chimps differ by something like 30 million base pairs. What, you think somehow random mutations are somehow going to get a human being, in one generation, to go back to a genome interfertile with chimps? Without more or less looking like a chimp?

It's like you're making negative progress. First, you want us to believe you can go from 100% interfertility to 0 in a single generation, and now, even more implausibly, you want us to believe you can go from 0 to 100% interfertility in a generation.

Which is easier? To drop a china teacup on the ground and have it break into a few hundred pieces? Or to sweep up all those pieces, drop them on the floor, and expect a teacup to form?

I think you know less about how evolutionary theory works now than you did a year and a half ago. How is that possible?

You know something no one else knows - how many 'base pairs' it takes to make a barrier to freely interbreeding.

We could have used that information ages ago. We have had to use general arguments.

So - how many base pairs does it take to make an organism type that can breed with X unable to breed with X?

Magellan

sylas

March 28th 2011, 01:45 AM

So - how many base pairs does it take to make an organism type that can breed with X unable to breed with X?

Guess what... there's no sharp dividing line. Neither did Eric imply there was such a number.

Eric said -- and he's right -- that the difference between humans and chimps involves a great many base pairs.... and this makes it impossible to get back to something close enough to mate with a chimp in a single generation. That doesn't say you can tell whether two individuals are going to be able to breed simply by counting base pairs. It means that the two species are to far different from each other to suddenly recover fertility in a single generation. (Nor, in fact, in any number of generations; but the reasons for that go a bit beyond the topic here.)

Consider the simulation I have written, in which individuals are represented as a sequence of numbers (roughly analagous to a sequence of genes with the different numbers being different alleles)

Given two sequences, they are considered able to mate with each other if the sum of the squares of the differences is less than a given threshold.

Now from this, it is easily to calculate how many mutations it would require to alter one genome into form that is fertile with another. But the number will vary depending on how evenly those mutations are distributed amongst the bases, in the simulation. That's just a mathematical theorem given the abstractions used.

The situation in biology is much more complicated again than my simple program. To speak of a certain number of base pair differences as being what it takes to get infertility is not sensible or realistic; and it is definitely not an implication of what Eric said.

What Eric said is correct. When there are a LOT of differences, you can't hold to get back to a compatible genome with one generation. That's all he said. The stuff about information concerning the number of base pairs to make a barrier is a notion you added all by yourself, as a result of failing to comprehend what Eric said.

Cheers -- sylas

ericmurphy

March 28th 2011, 01:51 AM

You know something no one else knows - how many 'base pairs' it takes to make a barrier to freely interbreeding.

It's a pretty safe guess, Magellan. We know the distance between humans and chimps genetically. We know—or at least we're pretty sure—humans and chimps are not interfertile.

You find either of these things hard to believe?

We could have used that information ages ago. We have had to use general arguments.

You can't even deal with my general arguments. You're making zero headway in even comprehending my model, let alone trying to critique it.

So - how many base pairs does it take to make an organism type that can breed with X unable to breed with X?

You are aware that different genomes are different sizes, right? Oh, wait—you don't.

We're not going to get into any kind of evidence that my model is correct until you have at least a basic understanding of the model itself.

Which I don't imagine will be happening any time soon.

ericmurphy

March 28th 2011, 02:30 AM

What Magellan still doesn't get about my model (to the extent he gets anything about my model) is that it doesn't matter how many mutations it takes to reproductively isolate two populations. All my model requires is that mutations accumulate, and that at some point interfertility goes to zero. If it doesn't take many mutations, then speciation occurs rapidly. If it takes a lot of mutations, then speciation occurs slowly.

Magellan's pleading that someone provide him an actual number (as if one number applied in all cases) helps him not at all. So long as the number isn't infinity, speciation will happen.

Faid

March 28th 2011, 02:44 AM

No.
If YOU mean 'freely interbreeding ' = 'less easy to interbreed' then all you can say is that CHimps find it less easy to breed with humans.The usual nonsense on your part. Chimps cannot just "freely" interbreed with humans; they cannot interbreed, PERIOD.

Nice try, Mags.

If YOU mean '100% unable to freely interbreed ' = '100% unable to freely interbreed ' then you can say Chimps are 100% unable to freely interbreed with Humans.Where on Earth did this redundant "100% able to fully interbreed" come from, and what does it mean? By "freely interbreed" I mean "100% able to INTERBREED".

What do YOU mean, Mags?

Spine. Grow some.

You work out what you mean and get back to me.

Tell us what YOU mean for once, and get back to us.

Faid

March 28th 2011, 02:52 AM

It's taken you this long to get to step 1 - Two parents give birth to a child that cannot breed with any member of Group A. SO by Page 180 we hopefully will be tackling Step 2. And personally I think it's wonderful to progress.

MagellanBecause before that, we thought that that child had materialized out of the Aether.

Face. Palm.

sylas

March 28th 2011, 05:30 AM

Here's a concrete example of one of Eric's graphs, obtained using data from my simulation program. I will be posting more details about this in the other thread, sometime tonight or tomorrow. But just to put here what is especially relevant...
https://lh4.googleusercontent.com/_WtnYwFZtgHI/TZBSB0F0sUI/AAAAAAAAJ74/GDGuG115G_U/s640/Fertility.jpg

This is a display of the fertility between groups. It is obtained from a simulation of 200 individuals. Each individual is at a unique "location"; but every mating season, they all sneak off for a night of wild nooky with a randomly selected partner. Children result, or not, depending only on the "genetic distance" between the mating couple. This model uses an unrealistic sharp dividing line. Below a certain separation distance, mating is always successful. Above that distance, it is never successful. There is, however, a proportion of fertile couples, which can be calculated as a percentage.

At generation 1000 in this simulation, individuals in the first 100 locations are suddenly isolated from the individuals in the other 100 locations, and thereafter all mating only takes place between couples in the same group... either group A, or group B. We can still calculate the fertility of hybrid couples, however, and see what happens to that.

The above image shows the fertility of AA (within group A), of BB (within group B) and of AB (couples with one parent from each group). There's lots of minor variation up and down as time goes by, since genomes are constantly varying a little bit by mutation. But look what happens at generation 1000. The fertility of AB couples declines rapidly, and levels off at zero by generation 1350.

More details and discussion will be showing up in the other thread....

Note that the fertility trace for AB looks a lot like Eric's graphs of fertility, but a lot less smooth. This is because in real life, and in decent simulations of real life, there's a lot of background variation going on all the time. The general shape, however, is given correctly in Eric's diagrams.

Cheers -- sylas

magellan004

March 28th 2011, 06:02 AM

ericmurphy

March 28th 2011, 10:27 AM

https://lh4.googleusercontent.com/_WtnYwFZtgHI/TZBSB0F0sUI/AAAAAAAAJ74/GDGuG115G_U/s640/Fertility.jpg

Note that the fertility trace for AB looks a lot like Eric's graphs of fertility, but a lot less smooth. This is because in real life, and in decent simulations of real life, there's a lot of background variation going on all the time. The general shape, however, is given correctly in Eric's diagrams.

Noise aside, the AB interfertility curve looks amazingly like this one:

http://www.planet-deepblu.com/~eric/graphic_links/SpeciesCurve.png

magellan004

March 28th 2011, 12:06 PM

ericmurphy

March 28th 2011, 12:54 PM

You could actually ask those questions in the appropriate thread, Magellan. This thread is for the discussion of how we get from one species to two species. The other thread (http://www.theologyweb.com/campus/showthread.php?145255-Simulation-of-Speciation) is specifically for the discussion of details of sylas's simulation.

ericmurphy

March 28th 2011, 12:55 PM

ericmurphy

March 28th 2011, 02:53 PM

Is it possible for a child of (say) yours to be born that can breed with Chimps?

That might give you an idea of the scope of the issues we are facing.

Magellan

Using sylas's simulation, we can arrive at an answer to this question.

I ran the simulation using default values, except for population size =1,000, for 1000 generations. Interfertility in the one population fell, as expected, to slightly above the lower bound of distances still allowing interfertility: around 64%. I then separated the initial population into two subpopulations of 500 individuals each. After 800 more generations, interfertility for AB pairings fell below 1%.

For AA and BB pairings, it remained above 60%

I then ran the simulation for another thousand generations. By generation 2,900, interfertility for AB pairings fell to 0. And there it stayed. After 63,000 generations it was still 0. After 100,000 generations, it was still 0. Meanwhile, AA and BB pairings maintained an interfertility of ~65%, which is expected given that differences of more than 60% would prevent interfertility.

I think that answers the question of whether humans and chimps will ever regain the interfertility they lost several hundred thousand generations ago.

magellan004

March 28th 2011, 03:37 PM

In any event, based on the results of sylas's simulation, I think the question of whether interfertility can ever take values other than 100% or zero is now settled. As if it weren't already settled by the existence of fertility clinics.

I think your arithmetic is questionable.

Post 1343

How do you calculate Fertility of -
1. An individual,

It's just the probability of an organism having offspring, Magellan. How hard is it? You take the number of successful productions of offspring, and divide by the number of attempts?

First of all how on earth do you know how many times an individual has attempted to have a child - especially if you are talking about Beetels.

It also mean that an individual who hasn't yet had a child is 0% fertile.

Sorry, I don't believe you.

Magellan

ericmurphy

March 28th 2011, 03:50 PM

I think your arithmetic is questionable.

Post 1343

First of all how on earth do you know how many times an individual has attempted to have a child - especially if you are talking about Beetels.

You watch them, Magellan. Beetles aren't shy. They'll do it right in front of you.

It also mean that an individual who hasn't yet had a child is 0% fertile.

Sorry, I don't believe you.

You know, the harder you try to come up with really, really stupid definitions like this, the stupider you look, Magellan. I don't know if your intention is to look really, really stupid. But that's more or less the effect.

Still not a scratch to my model, Magellan. Instead, deliberate misunderstandings, like assuming an organism that has not yet reached sexual maturity must have a fertility of zero. Let's see: we take zero productions of offspring divided by zero attempts.

I think the resulting answer is undefined, isn't it?

But seriously, Magellan: you are in essence arguing that it's impossible to make any estimates of fertility of either individuals or populations. Then why do we talk about fertility rates of human populations? Do you think all scientists are delusional?

Oh, right—you do think all scientists are delusional.

ericmurphy

March 28th 2011, 03:52 PM

Here's another possible definition of "fertility rate": number of offspring per female. Do you think that number is impossible to determine, Magellan?

ericmurphy

March 28th 2011, 04:21 PM

More interesting results in sylas's simulation.

Initial parameters:

population size: 1,000 split into two 500-member populations
genome size: 32
fertility bound: 10
other parameters left at defaults.

After one point two million generations: AA/BB pairings fertility: ~50%; AB pairings, 0.

magellan004

March 28th 2011, 07:31 PM

You watch them, Magellan. Beetles aren't shy. They'll do it right in front of you.

You know, the harder you try to come up with really, really stupid definitions like this, the stupider you look, Magellan. I don't know if your intention is to look really, really stupid. But that's more or less the effect.

Still not a scratch to my model, Magellan. Instead, deliberate misunderstandings, like assuming an organism that has not yet reached sexual maturity must have a fertility of zero. Let's see: we take zero productions of offspring divided by zero attempts.

I think the resulting answer is undefined, isn't it?

But seriously, Magellan: you are in essence arguing that it's impossible to make any estimates of fertility of either individuals or populations. Then why do we talk about fertility rates of human populations? Do you think all scientists are delusional?

Oh, right—you do think all scientists are delusional.

Are you kidding? The fertility rate in human populations has a straight forward formula.
You don't have a formula.

When I ask for your formula you invariably come up with things like 'The number of attempts.'
Then you assume that because an individual hasn't had a child then the individual must be a juvenile.

I haven't the foggiest notion of why you keep babbling about fertility. It's got nothing to do with anything.

Unless you can outline a formula and link to a reference that discusses that formula I will assume you have no idea what fertility of an individual means.

Magellan

sylas

March 28th 2011, 07:36 PM

Mind if I ask about some calculations and the graph you posted?

Please do! This is why I gave a simulation. Since it is something we can run and test and code, many of the concrete questions can be answered very definitely. The general model, however, admits many different possible ways it can occur.

1. With group AA line in the graph , is that showing the percentage of fertile couples based on one individual being paired with -
every other AA individual or with one randomly selected AA individual?

It's done with every other individual.

You could never hope to do such a thing in real life. The best we can do is take a few samples, and apply statistical methods to infer the population percentage. When you sample a population, rather than test every single possible pair, what you get is an estimate of fertility, with error bounds. The error bounds get smaller as the sample size gets larger.

The fact that I am able to do complete testing for all pairs means that the fertility number I get is exact, and the display is showing the real change in fertility, including real random variations up and down within a single population as time goes by. It's not a measurement error or estimate error; it's a real change in group fertility.

Did that calculation for a couple and any resultant 'Yes, they are a fertile couple' lead to the children that form the next generation, or did the next generation come from a separate calculation?

The new generation comes from a random pairing of individuals, without any regard to their fertility. There's also no gender. They are hermaphrodites, with no division into male and female. Any pair can be mated, although not all are fertile.

Hence, if you have a population of size n, then you have to check n(n-1)/2 pairs to measure the fertility with full accuracy, but a new generation is obtained by actually using only n/2 of the pairs to try and get children.

2. How did you calculate the AB line? (I don't understand what you mean 'couples with one parent from each group') Was every AA individual paired with every BB individual? I take it that no children resulting from such a calculation were used as inputs for the next generation?

This simulation doesn't worry about haploidy and diploidy. It's not essential, and not mentioned in Eric's model either. Individuals are either in group A, or in group B. The labels "AA", "AB" and "BB" refer to couples, not to individuals.

The "AB" line is obtained by taking every possible pair of individuals, one from group A and one from group B. If group A has n1 individuals, and group B has n2 individuals, then there are n1n2 possible pairs needing to be tested. The line is proportion of those pairs that are fertile. But note that once isolation is imposed, you never generate children from hybrid pairs, whether they are fertile or not.

If you would prefer that I didn't ask such questions just say so.

No, please do! Such questions really help me to explain what the program is doing, and also give some useful insights into where the simulation is different from reality. In reality, for example, its not possible to get all the data you need to calculate properties of groups of things precisely. Science uses sampling to infer group properties, and there's a whole field of mathematics that deals with to figure things out by sampling -- statistics.

Eric's right that the questions would be well suited to the other thread, but I don't mind answering basic questions like this here. I do think it is relevant to this thread to see how the simulation relates to the discussions going on here.

In fact, since you started this thread, you actually get to decide what's on topic here or not, according to our decorum; not Eric or I.

Cheers -- sylas

magellan004

March 28th 2011, 07:56 PM

Please do! This is why I gave a simulation. Since it is something we can run and test and code, many of the concrete questions can be answered very definitely. The general model, however, admits many different possible ways it can occur.

It's done with every other individual.

You could never hope to do such a thing in real life. The best we can do is take a few samples, and apply statistical methods to infer the population percentage. When you sample a population, rather than test every single possible pair, what you get is an estimate of fertility, with error bounds. The error bounds get smaller as the sample size gets larger.

The fact that I am able to do complete testing for all pairs means that the fertility number I get is exact, and the display is showing the real change in fertility, including real random variations up and down within a single population as time goes by. It's not a measurement error or estimate error; it's a real change in group fertility.

The new generation comes from a random pairing of individuals, without any regard to their fertility. There's also no gender. They are hermaphrodites, with no division into male and female. Any pair can be mated, although not all are fertile.

Hence, if you have a population of size n, then you have to check n(n-1)/2 pairs to measure the fertility with full accuracy, but a new generation is obtained by actually using only n/2 of the pairs to try and get children.

This simulation doesn't worry about haploidy and diploidy. It's not essential, and not mentioned in Eric's model either. Individuals are either in group A, or in group B. The labels "AA", "AB" and "BB" refer to couples, not to individuals.

The "AB" line is obtained by taking every possible pair of individuals, one from group A and one from group B. If group A has n1 individuals, and group B has n2 individuals, then there are n1n2 possible pairs needing to be tested. The line is proportion of those pairs that are fertile. But note that once isolation is imposed, you never generate children from hybrid pairs, whether they are fertile or not.

No, please do! Such questions really help me to explain what the program is doing, and also give some useful insights into where the simulation is different from reality. In reality, for example, its not possible to get all the data you need to calculate properties of groups of things precisely. Science uses sampling to infer group properties, and there's a whole field of mathematics that deals with to figure things out by sampling -- statistics.

Eric's right that the questions would be well suited to the other thread, but I don't mind answering basic questions like this here. I do think it is relevant to this thread to see how the simulation relates to the discussions going on here.

In fact, since you started this thread, you actually get to decide what's on topic here or not, according to our decorum; not Eric or I.

Cheers -- sylas

Thanks for those answers .
I didn't phrase my question 2 correctly . I asked 'Was every AA indiidual paired wih every BB individual?' I meant 'Was every A individual paired with every B individual?' and you answered it that way anyway.

As far as it being my Thread - Eric has tried several times to shoo me off. :tongue:

Magellan

ericmurphy

March 28th 2011, 08:01 PM

Are you kidding? The fertility rate in human populations has a straight forward formula.
You don't have a formula.

Oh, really? And what is that formula, Magellan? And how does it differ for the formula for any other sexually-reproducing organism? One "formula" I know of is simply the number of offspring per female in the population. sylas's formula in his simulation: it's simply the percentage of viable mating partners any given member of a population has, where "viable" is defined in terms of genetic distance from any potential partner.

When I ask for your formula you invariably come up with things like 'The number of attempts.'
Then you assume that because an individual hasn't had a child then the individual must be a juvenile.

I don't assume any such thing, Magellan. And the fact of the matter is, it doesn't matter what formula you use. All that matters is that there is some way to measure fertility, and that you use the same method at all times throughout the model.

I haven't the foggiest notion of why you keep babbling about fertility. It's got nothing to do with anything.

I haven't the foggiest notion why you continue to make claims about a model, or indeed a theory, about which you know nothing.

"Fertility" is a central concept in my model. It is also a central concept in any notion of speciation. It is also a central concept in evolutionary theory. That you think otherwise is indicative of your own deep ignorance about all three.

Unless you can outline a formula and link to a reference that discusses that formula I will assume you have no idea what fertility of an individual means.

You can assume whatever you want, Magellan. You do, after all, assume that all scientists are liars and frauds. But your assumptions about what I know about fertility don't change the fact that I was able to pretty accurately predict the output of sylas's simulation before he even wrote it. You can say all you want that that's because sylas's simulation is based on my model, but how does that help you? Your job here is to show that my model is unworkable. But it's a little late for that, since sylas's model already demonstrates that it is workable, and leads to exactly the outcome I predicted it would lead to: two populations which cannot interbreed, starting with one population of freely-interbreeding individuals.

Your move.

ericmurphy

March 28th 2011, 08:03 PM

As far as it being my Thread - Eric has tried several times to shoo me off. :tongue:

Uh, no. I fully enjoy responding to your posts, Magellan; you're about the only creationist I ever engage with anymore. What I do say is, if you can't address my posts, you're certainly invited to abandon the thread, as you have always done in the past.

magellan004

March 28th 2011, 08:45 PM

Oh, really? And what is that formula, Magellan? And how does it differ for the formula for any other sexually-reproducing organism? One "formula" I know of is simply the number of offspring per female in the population. sylas's formula in his simulation: it's simply the percentage of viable mating partners any given member of a population has, where "viable" is defined in terms of genetic distance from any potential partner.

I don't assume any such thing, Magellan. And the fact of the matter is, it doesn't matter what formula you use. All that matters is that there is some way to measure fertility, and that you use the same method at all times throughout the model.

I haven't the foggiest notion why you continue to make claims about a model, or indeed a theory, about which you know nothing.

"Fertility" is a central concept in my model. It is also a central concept in any notion of speciation. It is also a central concept in evolutionary theory. That you think otherwise is indicative of your own deep ignorance about all three.

You can assume whatever you want, Magellan. You do, after all, assume that all scientists are liars and frauds. But your assumptions about what I know about fertility don't change the fact that I was able to pretty accurately predict the output of sylas's simulation before he even wrote it. You can say all you want that that's because sylas's simulation is based on my model, but how does that help you? Your job here is to show that my model is unworkable. But it's a little late for that, since sylas's model already demonstrates that it is workable, and leads to exactly the outcome I predicted it would lead to: two populations which cannot interbreed, starting with one population of freely-interbreeding individuals.

Your move.

Sprung! You have no idea what you mean by 'the fertility of an individual.'

I'm happy to leave it at that.

magellan

sylas

March 28th 2011, 09:03 PM

Sprung! You have no idea what you mean by 'the fertility of an individual.'

I'm happy to leave it at that.

That is a completely bizarre statement, which has no support whatever in the text you have quoted. I truly have no idea how on earth you obtain that inference, which is why I still remain pretty sure this is just some kind of weird trolling game you are playing; making statements you actually know don't make any sense, but which can help derail the discussion some more.

I'm glad you and I have just been able to have a cordial and constructive exchange, and I hope we can have some more. But things like the above remark are just off the planet. Eric has a very good notion of the fertility of an individual -- including the recognition that the notion of fertility is a general one, which can be defined in a whole range of different ways if you wanted to make it more precise for some reason.

The general model for speciation does not require any one particular fertility definition. Pretty much any definition you like which captures the basic idea of the capacity to have viable descendants will work.

Cheers -- sylas

ericmurphy

March 28th 2011, 09:13 PM

Sprung! You have no idea what you mean by 'the fertility of an individual.'

I'm happy to leave it at that.

magellan

Except that I do, Magellan. I've given you multiple ways of measuring the fertility of an individual. How that amounts to "having no idea" what it means is something of a mystery.

But it's fairly entertaining that you think fertility has nothing to do with evolutionary theory or models of speciation.

And how do you explain my eerily accurate predictions of what sylas's simulation would show, even before he wrote it? That doesn't seem like the kind of thing I could do if I had "no idea" what is going on in my model (in which fertility plays a central role).

ETA: it seems like many if not all of Magellan's objections to my model, and my explanations of it, revolve on a lack of quantitative precision. But I see this as a strength of my model, not a weakness. My model is an extremely general description of how allopatric speciation could come about. Without doing any sort of quantitative analysis at all, but merely working through the processes of reproduction, mutation, selection, and drift, I was able to construct a model of the process of speciation that seems to work well with any reasonable quantitative inputs. No matter what initial values I put in for population size, genome size, or limits on differences still allowing for offspring, I still get the same results: two populations which maintain a fairly high (and constant) level of interfertility, between which interfertility declines to zero and stays there while the genetic distance between the two populations increases, apparently without bound. The only difference changing the initial parameters makes is the time it takes for interfertility between populations to decline to zero, and what ultimate (and constant) value intra-population fertility eventually assumes.

I see this as a triumph of the predictive power of a model.

So out of curiosity, Magellan: how do you explain the output of sylas's computer simulation?

ericmurphy

March 28th 2011, 09:25 PM

sylas

March 28th 2011, 09:58 PM

I have some issues with that graph, Eric. The vertical axis is labeled "number of individuals", but individuals don't have a "number of differences" unless with a specific reference point. And that reference point is not entirely clear.

It does make good sense as a basis for describing the fertility of one individual, by looking at the differences between that one individual and all their prospective partners. And indeed, I had considered generating statistics of that form for my simulation, though in the end I left it out. But the whole graph is called "interfertility", not "fertility", which sounds like a comparison of groups, done by counting up pairs.

Here's what I think, when I look at the graph.

Given a population, you can take an individual, and obtain a distribution of the distances between that individual and others in the population, at a point in time. You'll get a bell curve of the same form, and the axis labels would make sense; but in this case fertility is the normalized area under the curve up to the threshold whether the differences are sufficient for sterility. So you couldn't put fertility, or interfertility on the other axis.

Cheers -- sylas

magellan004

March 28th 2011, 10:19 PM

So out of curiosity, Magellan: how do you explain the output of sylas's computer simulation?

I am not sure I understand sylas's program yet. I need to go through it and my C programming knowledge is minimal.

I notice in his graph of Fertility he starts with two (or three) groups. I am not sure what they represent or what the calculations are. But I just need to go through it all. Until I understand his calculations there's no point in me commenting further.

(I will be away tomorrow for a few days so I won't have much chance to digest Sylas's program until later. )

Magellan

ericmurphy

March 29th 2011, 12:38 AM

I have some issues with that graph, Eric. The vertical axis is labeled "number of individuals", but individuals don't have a "number of differences" unless with a specific reference point. And that reference point is not entirely clear.

Well, you don't have the benefit of my earlier explanation of the graph. The "number of individuals" refers to the number of individuals who have a particular number of differences compared to an average genome of the other population. In other words, if we take the typical genome of a member of population A (in essence, the most frequent allele at a particular locus), members of population B will have a particular number of differences relative to that typical genome. The height of the histogram at any particular number of differences reflects the number of individuals with that number of differences. In your simulation, the center of the curve would refer to the median number of differences. The ends of the normal distribution would correspond to the minimum and maximum differences.

It does make good sense as a basis for describing the fertility of one individual, by looking at the differences between that one individual and all their prospective partners. And indeed, I had considered generating statistics of that form for my simulation, though in the end I left it out. But the whole graph is called "interfertility", not "fertility", which sounds like a comparison of groups, done by counting up pairs.

Think of it this way. Look at the median value for a particular generation in your simulation. That would correspond to the highest point on the curve in my diagram. The minimum distance would correspond to the leftmost point on the curve in my diagram. The maximum distance would correspond to the maximum distance. The normal distribution is an assumption of my model, based on the fact that most samples based on a random underlying process (like random mutations) form a normal distribution.

Here's what I think, when I look at the graph.

Given a population, you can take an individual, and obtain a distribution of the distances between that individual and others in the population, at a point in time. You'll get a bell curve of the same form, and the axis labels would make sense; but in this case fertility is the normalized area under the curve up to the threshold whether the differences are sufficient for sterility. So you couldn't put fertility, or interfertility on the other axis.

The fertility, or interfertility, is a separate y coordinate relative to the x axis, which is the number of differences (i.e., the "distance" in your simulation). As in your simulation, below a given distance, you have 100% interfertility; above it, you have zero interfertility. Also, as in your simulation, as we move forward in time (increasing numbers of mutations), we have more and more individuals who have above the fertility threshold. In my diagram, the curve of the normal distribution would move to the right with increasing time as more and more individuals exceed the fertility threshold wrt the number of distance they have with members of the other population.

ericmurphy

March 29th 2011, 12:45 AM

I am not sure I understand sylas's program yet. I need to go through it and my C programming knowledge is minimal.

Well, even if your knowledge of C were fine, I'd be surprised if you understood sylas's simulation, because you don't understand the model on which it is based. I think you'd need to understand that model before you could understand the implementation of it as a computer simulation.

I notice in his graph of Fertility he starts with two (or three) groups. I am not sure what they represent or what the calculations are.

There are two groups: A and B. There are three sets of matings: matings between members of A, matings between members of B, and matings between members of A and B. That's what "AA," "BB," and "AB" stand for.

The calculations are simply the sum of the squares of the distances between any two mating pairs. The simulation takes each member of A, mates it with each other member of A, and if that value exceeds a threshold, no offspring are produced. If the value does not exceed that threshold, offspring are definitely produced. The same is done for each member of B.

Then, each member of A is paired with each member of B, and the same calculation is performed. The only difference is that since no actual interbreeding between A and B is occurring, there are no descendants of those matings. All we're doing is looking at the distance between each member of A and each member of B.

But I just need to go through it all. Until I understand his calculations there's no point in me commenting further.

My knowledge of C is unlikely to be even as good as yours, Magellan, but at least conceptually I understand what sylas's simulation is doing.

But I'm curious, Magellan: I admit I cannot follow the programming logic in sylas's simulation. Nevertheless, I was able to accurately predict the output of the simulation. How is that possible?

magellan004

March 29th 2011, 01:39 AM

There are two groups: A and B. There are three sets of matings: matings between members of A, matings between members of B, and matings between members of A and B. That's what "AA," "BB," and "AB" stand for.

The calculations are simply the sum of the squares of the distances between any two mating pairs. The simulation takes each member of A, mates it with each other member of A, and if that value exceeds a threshold, no offspring are produced. If the value does not exceed that threshold, offspring are definitely produced. The same is done for each member of B.

Then, each member of A is paired with each member of B, and the same calculation is performed. The only difference is that since no actual interbreeding between A and B is occurring, there are no descendants of those matings. All we're doing is looking at the distance between each member of A and each member of B.

That's what I sort of thought (about three groups) but then how does the physical sparation come into it. If Group A's do not breed with Group B's at the start, then what changes when B and A are physically separated?

If intially there is breeding between Group A and Group B then in what sense are A and B separate groups?

Magellan

ericmurphy

March 29th 2011, 02:34 AM

That's what I sort of thought (about three groups)
How are there three groups, Magellan? There are two groups: A and B. There is no third group.

but then how does the physical sparation come into it. If Group A's do not breed with Group B's at the start, then what changes when B and A are physically separated?

It comes into it because there is no selective disadvantage to A being unable to interbreed with B, and vice versa, because no such interbreeding is happening anyway:

http://www.planet-deepblu.com/~eric/graphic_links/Isolation.png

Members of A which cannot interbreed with other members of A are selected against, and (in this simplified model where interfertility is either complete or zero) leave no descendants. Same with members of B which cannot interbreed with B. But members of either group which are not interfertile with the opposite group are not selected against, and therefore differences between the two groups grow over time. We see this in sylas's simulation: intra-group differences never exceed a certain level, whereas differences inter-group grow without bound. I discuss this phenomenon in the other thread. (http://www.theologyweb.com/campus/showthread.php?145255-Simulation-of-Speciation&p=3200054#post3200054)

This is why isolation is important, and it's why interfertility is important. Your failure to grasp these features of my model, and of sylas's simulation based on that model, is why it makes no sense to you.

If intially there is breeding between Group A and Group B then in what sense are A and B separate groups?

There is no breeding between A and B after the initial separation from X into subgroups.

Imagine this: scientists take a population of freely-interbreeding lab rats, and separate them into two groups. Members of each group are free to mate, but members are not free to mate with members of the other group.

Every hundred generations, samples from each group are placed together, and the rate of fertility is measured. Any offspring are, well, because we're being humane here, released into the wild and are no longer part of the experiment. The important thing is that as a practical matter there is no interbreeding between A and B. If we could simply compare the genomes of two actual, living organisms and determine that interbreeding was impossible, we wouldn't need to actually have any interbreeding at all. We could simply look at the genomes and see the differences accumulating over time.

Over hundreds of thousands of generations (our scientists are either extremely long-lived or have passed down their research to future generations), we note, as is shown in sylas's simulation, that intra-group genetic distances do not exceed a value set by whatever still allows reasonable levels of reproductive fitness. Inter-group genetic distances rapidly exceed that value, because there are no selective forces acting against genetic drift.

After a large number of generations (depending on how much genetic distance prevents interbreeding), we get speciation. Again, as sylas's simulation demonstrates.

There is no interbreeding between A and B, except as allowed for testing purposes by the experimenters as a method of determining interfertility. No descendants of A/B hybrids are allowed into either population. Other than for purposes of measuring interfertility, A/B crosses have no effect on the experiment.

magellan004

March 29th 2011, 04:20 AM

How are there three groups, Magellan? There are two groups: A and B. There is no third group.

It comes into it because there is no selective disadvantage to A being unable to interbreed with B, and vice versa, because no such interbreeding is happening anyway:

http://www.planet-deepblu.com/~eric/graphic_links/Isolation.png

Members of A which cannot interbreed with other members of A are selected against, and (in this simplified model where interfertility is either complete or zero) leave no descendants. Same with members of B which cannot interbreed with B. But members of either group which are not interfertile with the opposite group are not selected against, and therefore differences between the two groups grow over time. We see this in sylas's simulation: intra-group differences never exceed a certain level, whereas differences inter-group grow without bound. I discuss this phenomenon in the other thread. (http://www.theologyweb.com/campus/showthread.php?145255-Simulation-of-Speciation&p=3200054#post3200054)

This is why isolation is important, and it's why interfertility is important. Your failure to grasp these features of my model, and of sylas's simulation based on that model, is why it makes no sense to you.

There is no breeding between A and B after the initial separation from X into subgroups.

Imagine this: scientists take a population of freely-interbreeding lab rats, and separate them into two groups. Members of each group are free to mate, but members are not free to mate with members of the other group.

Every hundred generations, samples from each group are placed together, and the rate of fertility is measured. Any offspring are, well, because we're being humane here, released into the wild and are no longer part of the experiment. The important thing is that as a practical matter there is no interbreeding between A and B. If we could simply compare the genomes of two actual, living organisms and determine that interbreeding was impossible, we wouldn't need to actually have any interbreeding at all. We could simply look at the genomes and see the differences accumulating over time.

Over hundreds of thousands of generations (our scientists are either extremely long-lived or have passed down their research to future generations), we note, as is shown in sylas's simulation, that intra-group genetic distances do not exceed a value set by whatever still allows reasonable levels of reproductive fitness. Inter-group genetic distances rapidly exceed that value, because there are no selective forces acting against genetic drift.

After a large number of generations (depending on how much genetic distance prevents interbreeding), we get speciation. Again, as sylas's simulation demonstrates.

There is no interbreeding between A and B, except as allowed for testing purposes by the experimenters as a method of determining interfertility. No descendants of A/B hybrids are allowed into either population. Other than for purposes of measuring interfertility, A/B crosses have no effect on the experiment.

I don't think you understood my question about Groups at the start.
If there was no interbreeding at the start between Group A and Group B then how will a physical barrier being placed half way through affect anything?

Magellan

Faid

March 29th 2011, 06:23 AM

Um, Mags:
There is no breeding between A and B after the initial separation from X into subgroups.You had no problem incorporating those concepts in your own models, way back at the start of the thread.

Why are you pretending not to get them now?

magellan004

March 29th 2011, 07:31 AM

Um, Mags:You had no problem incorporating those concepts in your own models, way back at the start of the thread.

Why are you pretending not to get them now?

In Sylas's graph , which of these is true?
1. Before the physical separation there were two groups - Group A and Group B.
2. Before the physical separation there were not two groups- A and B. There was only Group A.
3. Before the physical separation there were not two groups- A and B. There was only Group B.
4. Before the physical separation there were two groups- A and B but Group A members did not interbreed with Group B members.
5. Before the physical separation there were two groups- A and B and Group A members did interbreed with Group B members.

Magellan

magellan004

March 29th 2011, 07:46 AM

That is a completely bizarre statement, which has no support whatever in the text you have quoted. I truly have no idea how on earth you obtain that inference, which is why I still remain pretty sure this is just some kind of weird trolling game you are playing; making statements you actually know don't make any sense, but which can help derail the discussion some more.

I'm glad you and I have just been able to have a cordial and constructive exchange, and I hope we can have some more. But things like the above remark are just off the planet. Eric has a very good notion of the fertility of an individual -- including the recognition that the notion of fertility is a general one, which can be defined in a whole range of different ways if you wanted to make it more precise for some reason.

The general model for speciation does not require any one particular fertility definition. Pretty much any definition you like which captures the basic idea of the capacity to have viable descendants will work.

Cheers -- sylas

I have repeatedly said I am uninterested in fertility. It has no bearing on our discussion - on whether one individual has the ability to interbreed with another individual or not.

Eric keeps presenting graphs and comments about 'Fertile this ' and 'Interfertile that'. I simply have no idea what he is talking about.

There is only one issue that is relevant - 'Does this individual have the ability to interbreed with that individual'.

I did not define the issue that way. I was presented with that as the issue.

For example, with Orcas, no one is interested in whether 'This particular Orca is fertile or not'.
What is of interest is whether this particular Orca has the ability to interbreed with that Orca.

Why? Because that has been presented as the crux of Speciation - not how fertile a particular individual is.

What is more, I have repeatedly asked Eric that, should he wish to avoid confusion, then he can and should stick to the terms he selected as defining the issue - 'The ability of one individual to interbreed with another individual.' There is simply no need to insert 'Fertility' or 'Interfertility' or any other terms. We have an agreed and adequate vocabulary for discussing the issue at hand.

Most of this thread has been dealing with this desperate clutching at 'labels'. If Eric so desperately needs to use the term 'Fertility' then I am telling him, and you, that I have no idea what he means by that term. Therefore , as usual, he can do one of two things - explain what he means until we have agreement or persist in using non-understood terms.

Magellan

sylas

March 29th 2011, 07:58 AM

In Sylas's graph , which of these is true?
1. Before the physical separation there were two groups - Group A and Group B.
2. Before the physical separation there were not two groups- A and B. There was only Group A.
3. Before the physical separation there were not two groups- A and B. There was only Group B.
4. Before the physical separation there were two groups- A and B but Group A members did not interbreed with Group B members.
5. Before the physical separation there were two groups- A and B and Group A members did interbreed with Group B members.

Point 5 is correct, which means point 1 is also true. My graph does display the details for the two groups, even before they become isolated.

Before the physical separation, the identification of groups has about as much significance as defining groups of humans based on whether their first name begins with A-M, or with N-Z. You can get all the statistics you like for the two groups, and that is what I did in the graphs provided.

The way the groups work in the simulation, children get allocated to one group or the other without any consideration of the groups their parents belong to, up until the separation occurs. After that, mating only occurs within a group, and children remain in the same group as their parents.

PS. You are going to have to develop an interest in fertility if you want to actually understand the models. If you don't understand the models, then you have no hope of making any coherent critique of them.

Understand first. Then critique, if you can see any problems.

Added further in edit.

One thing you will need to understand is that the precise definition of fertility is not actually important! Eric is precisely correct not to give a precise definition; the model is a general model, which works in many different circumstances.

These things are required. There is SOME notion of fertility. Whether it is the number of descendants, the capacity to attract a mate, the ability to bear a child, the chance of a child being fertile, really doesn't matter. What matters for allopatric speciation is that when individuals become too different from each other, they lose the ability to have children together. It might be lost gradually (usually the case) depending on distance, or have some more simple restriction.

It DOESN'T MATTER.

And until you UNDERSTAND that it doesn't matter -- you don't understand the model.

ericmurphy

March 29th 2011, 10:33 AM

I don't think you understood my question about Groups at the start.
If there was no interbreeding at the start between Group A and Group B then how will a physical barrier being placed half way through affect anything?

Magellan

Read this part:

We start with a single, freely-interbreeding ancestral population X. All members of this population can interbreed with each other.
At some point, some event or process divides X into two freely-interbreeding subpopulations, A and B. At the time of initial separation, all members of A and B are interfertile not only with other members of their own population but also with members of the other population, and would be interfertile with members of X if there still were any.
The isolating event or process could be geographic isolation due to a new mountain range forming, climate change forming a barrier between two regions, migration patterns reducing or eliminating gene flow between remote areas inhabited by the original population, or colonization of an island by either subpopulation.

We've been through this a million times already, Magellan. We start out with a single freely-interbreeding ancestral population X. Later, that single population is separated into two subpopulations, A and B, by some sort of geographical barrier.

Where does the left-hand portion of this diagram come from?

http://www.theologyweb.com/campus/attachment.php?attachmentid=65542&d=1301386745

Did you think there were already two separate, non-interbreeding populations before the existence of the barrier? How could you think that? How long have we been talking about an initial, single ancestral population X? Three weeks now? I explain this in the very first sentence of the description of my model.

Seriously; I've been through this with you so many times before it's impossible to believe you don't remember this. The only reasonable conclusion is that you're stalling for time, but I just can't figure out how you think that's going to help you. I can do this for the next ten years.

ericmurphy

March 29th 2011, 10:39 AM

ericmurphy

March 29th 2011, 10:47 AM

I have repeatedly said I am uninterested in fertility.
That's your single biggest problem with this whole discussion, Magellan. Fertility is central to the concept of how speciation happens. If you still don't get this, you're truly lost.

It has no bearing on our discussion - on whether one individual has the ability to interbreed with another individual or not.

Then why does sylas's simulation do nothing BUT compare the interfertility of different individuals? That's essentially all the program does, Magellan.

Eric keeps presenting graphs and comments about 'Fertile this ' and 'Interfertile that'. I simply have no idea what he is talking about.

I'm well aware you have no idea what I'm talking about. That's why you're making no headway in even understanding my model, let alone critiquing it.

There is only one issue that is relevant - 'Does this individual have the ability to interbreed with that individual'.

And at the same time you think fertility has no relevance? What do you think fertility is, Magellan? You just accused me of not knowing what fertility is, and yet you now say the relevant issue is whether one individual has the ability to interbreed with another individual!

I did not define the issue that way. I was presented with that as the issue.

Actually, you did. You posed the question: how can we start out with one group of beetles which can all interbreed, and end up with two separate groups of beetles which cannot interbreed? That was your question, Magellan.

For example, with Orcas, no one is interested in whether 'This particular Orca is fertile or not'.

They're certainly interested in whether two different groups are interfertile or not.

What is of interest is whether this particular Orca has the ability to interbreed with that Orca.

Do you not get that "ability to interbreed" and "interfertile" are essentially the same thing?

Why? Because that has been presented as the crux of Speciation - not how fertile a particular individual is.

The crux of the issue is whether or not individuals from two different populations are interfertile. That is what sylas's simulation determines.

What is more, I have repeatedly asked Eric that, should he wish to avoid confusion, then he can and should stick to the terms he selected as defining the issue - 'The ability of one individual to interbreed with another individual.' There is simply no need to insert 'Fertility' or 'Interfertility' or any other terms. We have an agreed and adequate vocabulary for discussing the issue at hand.

I'm sorry, Magellan, but I'm not going to accede to your requirement that I simply replace every word I use with the definition for that word. "Interfertility" means "ability to interbreed." A measure of interfertility is a measure of ability to interbreed. If you can't be troubled to learn the definition of words like "interfertility," I'm afraid you're not going to make much progress in this discussion.

Most of this thread has been dealing with this desperate clutching at 'labels'. If Eric so desperately needs to use the term 'Fertility' then I am telling him, and you, that I have no idea what he means by that term. Therefore , as usual, he can do one of two things - explain what he means until we have agreement or persist in using non-understood terms.

I have defined all the terms I've used in this discussion ad nauseam. If you still can't figure out what they mean, I'm not sure what you expect me to do about that. Anyone who wants to discuss the concept of speciation without using terms like "interfertility" is not going to have a very productive conversation.

ericmurphy

March 29th 2011, 12:03 PM

Here's the output from a run I did of sylas's simulation this morning. Initial values were:

Population size: 1,000
Genome length: 32
Mutations added per child: 1
Distance bound on full fertility: 20
Distance causing full sterility: 21

All other values are the defaults.

I let the simulation run for one hundred thousand generations as a single, freely-interbreeding population:

EvoSim version 1.0.1.sylas, March 2011
Collecting initial simulation parameters...
Population size [200] > 1000
Genome length [16] > 32
Max base value [100] >
Mutations added per child [5] > 1
Distance bound on full fertility [20] >
Distance causing full sterility [21] >
Isolation barrier; size group A, or 0 for no barrier [0] > 0
Random number seed [10000000] >
Spread of initial base values; number of possible values [1] >
Simulation initialized; ready to go....
> e 100000 1000
No barrier in place. Stats for whole population
gen MaxD MeanD mates
0: 0 0.0 100.0%
1000: 52 19.2 62.7%
2000: 55 19.1 64.2%
3000: 55 19.1 63.7%
4000: 53 19.1 63.7%
5000: 57 19.5 60.5%
6000: 59 19.4 61.1%
7000: 60 19.2 62.8%
8000: 54 19.9 57.6%
9000: 52 19.3 61.9%
10000: 55 19.3 61.9%
11000: 53 19.5 60.7%
12000: 50 19.1 63.3%
13000: 51 19.0 64.5%
14000: 53 19.2 62.6%
15000: 53 19.4 61.5%
16000: 54 19.2 62.4%
17000: 57 19.2 62.8%
18000: 53 19.5 60.4%
19000: 54 19.2 63.2%
20000: 60 19.5 60.5%
21000: 52 19.3 62.1%
22000: 54 19.4 61.5%
23000: 53 19.6 59.6%
24000: 61 19.8 58.8%
25000: 58 19.6 60.4%
26000: 50 19.2 62.9%
27000: 54 19.3 62.4%
28000: 53 19.1 63.8%
29000: 47 19.0 64.1%
30000: 54 19.5 61.0%
31000: 57 19.4 61.1%
32000: 53 19.7 59.5%
33000: 59 19.4 61.6%
34000: 55 19.3 62.7%
35000: 55 18.9 65.1%
36000: 52 19.9 57.7%
37000: 55 19.4 60.7%
38000: 53 18.9 64.6%
39000: 54 19.4 61.1%
40000: 54 19.5 60.8%
41000: 55 19.2 62.5%
42000: 53 19.0 64.1%
43000: 57 19.0 64.0%
44000: 53 19.6 60.0%
45000: 53 19.5 60.9%
46000: 50 19.2 62.5%
47000: 55 19.5 61.1%
48000: 59 19.5 60.8%
49000: 54 19.2 62.7%
50000: 52 19.3 62.0%
51000: 58 19.3 62.3%
52000: 58 19.5 60.6%
53000: 58 18.5 67.8%
54000: 54 19.5 60.6%
55000: 54 19.3 62.1%
56000: 52 19.3 62.4%
57000: 52 19.1 63.2%
58000: 54 19.0 64.1%
59000: 53 19.0 64.2%
60000: 59 19.5 61.1%
61000: 60 19.7 59.5%
62000: 53 20.0 57.3%
63000: 54 19.7 59.4%
64000: 53 19.4 61.2%
65000: 55 19.4 61.4%
66000: 55 19.6 60.3%
67000: 55 19.3 62.1%
68000: 64 19.1 63.9%
69000: 58 18.9 65.0%
70000: 53 19.3 61.8%
71000: 51 19.7 58.9%
72000: 54 19.4 61.1%
73000: 58 19.4 61.5%
74000: 56 19.5 61.3%
75000: 52 19.0 63.9%
76000: 59 18.9 64.8%
77000: 59 18.9 65.0%
78000: 56 19.4 61.1%
79000: 60 19.0 64.3%
80000: 56 19.2 63.2%
81000: 53 19.2 63.3%
82000: 56 19.4 61.4%
83000: 58 19.6 60.2%
84000: 53 19.6 59.4%
85000: 57 19.4 61.5%
86000: 52 19.3 62.3%
87000: 53 19.2 62.3%
88000: 54 19.3 62.3%
89000: 56 19.9 57.7%
90000: 59 18.8 65.7%
91000: 53 19.2 62.6%
92000: 54 19.6 60.0%
93000: 55 19.3 61.7%
94000: 59 19.2 63.3%
95000: 57 19.8 58.6%
96000: 56 19.2 62.7%
97000: 53 19.4 61.4%
98000: 56 19.6 60.1%
99000: 54 19.0 64.1%
100000: 54 19.0 64.1%

After 100,000 generations of this single population, the median distance, as expected, was 19. Clearly, selection pressures are at work, preventing the median distance from exceeding 20, the upper fertility bound. Since there is no selective advantage to lower distances, we should expect the median value to be near the upper bound.

I then ran the simulation for another 100,000 generations, but this time I split the population into two equally-sized subpopulations. All other parameters remained unchanged.

Distance bound on full fertility [20] >
Distance causing full sterility [21] >
Isolation barrier; size of group A [500] > 500
> e 100000 1000
data is: AA pairs | BB pairs | AB hybrid pairs
gen MaxD MeanD mates | MaxD MeanD mates | MinD MeanD mates
100000: 52 19.0 64.2% | 52 19.1 64.0% | 1 19.0 64.1%
101000: 55 19.4 61.2% | 51 19.4 60.9% | 7 33.9 3.7%
102000: 50 19.5 60.4% | 55 19.1 63.5% | 10 38.8 0.9%
103000: 49 19.3 62.1% | 48 19.0 63.9% | 14 47.7 0.0%
104000: 51 19.5 60.7% | 63 18.9 64.6% | 19 56.0 0.0%
105000: 63 19.3 62.5% | 65 19.2 63.6% | 20 66.4 0.0%
106000: 56 19.9 57.6% | 51 19.2 62.6% | 33 85.4 0.0%
107000: 51 19.5 61.1% | 55 19.6 59.9% | 34 87.5 0.0%
108000: 56 18.8 65.7% | 50 19.0 64.7% | 44 87.9 0.0%
109000: 56 18.8 65.9% | 54 19.6 60.4% | 43 94.3 0.0%
110000: 53 20.0 57.7% | 50 19.6 60.1% | 54 99.6 0.0%
111000: 53 19.6 59.9% | 54 19.6 59.9% | 41 88.4 0.0%
112000: 54 19.8 58.4% | 52 19.3 62.8% | 50 96.0 0.0%
113000: 52 19.5 60.4% | 51 19.8 57.9% | 62 118.1 0.0%
114000: 47 18.7 66.7% | 46 18.9 65.2% | 49 115.2 0.0%
115000: 51 19.6 60.0% | 53 19.5 60.3% | 57 109.3 0.0%
116000: 55 19.7 59.2% | 52 19.5 60.5% | 52 110.3 0.0%
117000: 48 19.2 62.6% | 56 19.2 62.8% | 63 127.4 0.0%
118000: 53 19.1 63.3% | 49 19.0 63.6% | 80 133.5 0.0%
119000: 48 19.6 60.0% | 53 19.1 63.9% | 92 159.7 0.0%
120000: 48 19.0 63.6% | 52 19.5 60.5% | 78 146.4 0.0%
121000: 54 19.2 62.9% | 48 19.7 58.9% | 93 161.9 0.0%
122000: 53 20.4 53.3% | 47 18.9 65.0% | 89 152.7 0.0%
123000: 50 19.1 63.2% | 56 19.8 58.8% | 81 144.2 0.0%
124000: 54 19.5 60.9% | 53 19.3 61.8% | 79 147.9 0.0%
125000: 51 19.4 61.6% | 53 20.0 57.3% | 89 161.3 0.0%
126000: 51 19.8 58.8% | 54 19.9 58.2% | 104 167.5 0.0%
127000: 48 19.5 60.5% | 57 19.3 62.3% | 86 161.5 0.0%
128000: 53 19.9 58.1% | 52 19.2 63.3% | 90 157.3 0.0%
129000: 50 19.8 58.3% | 52 19.5 61.2% | 97 165.5 0.0%
130000: 50 19.9 57.9% | 49 19.3 62.1% | 85 151.7 0.0%
131000: 47 19.5 60.9% | 46 19.2 62.4% | 106 176.4 0.0%
132000: 48 19.4 61.0% | 50 19.8 58.3% | 85 169.3 0.0%
133000: 47 19.3 61.9% | 56 19.2 63.4% | 95 175.2 0.0%
134000: 52 19.7 59.3% | 50 19.4 61.8% | 100 171.9 0.0%
135000: 49 19.6 59.6% | 49 19.2 62.3% | 89 167.3 0.0%
136000: 54 19.9 58.0% | 47 19.0 64.3% | 105 177.0 0.0%
137000: 55 19.9 57.5% | 52 19.6 60.2% | 100 183.0 0.0%
138000: 52 19.8 58.3% | 53 20.0 57.2% | 120 207.7 0.0%
139000: 50 19.4 62.1% | 58 19.2 63.2% | 125 200.7 0.0%
140000: 56 20.0 56.8% | 49 19.9 58.1% | 145 232.9 0.0%
141000: 51 20.4 53.7% | 49 19.4 61.4% | 144 245.2 0.0%
142000: 52 18.8 65.5% | 55 19.2 63.0% | 161 259.3 0.0%
143000: 55 19.8 58.3% | 48 19.8 58.1% | 162 260.1 0.0%
144000: 52 19.2 63.1% | 50 19.2 62.9% | 151 252.0 0.0%
145000: 52 19.1 63.4% | 51 20.3 54.2% | 166 259.3 0.0%
146000: 52 19.2 62.6% | 51 19.8 58.1% | 187 285.2 0.0%
147000: 48 19.3 62.4% | 50 19.2 62.4% | 167 259.4 0.0%
148000: 58 19.4 61.1% | 49 19.6 59.7% | 169 256.3 0.0%
149000: 49 19.9 57.5% | 53 18.7 66.8% | 150 263.7 0.0%
150000: 49 19.1 64.3% | 53 19.6 60.0% | 185 279.8 0.0%
151000: 49 19.7 58.7% | 50 19.3 62.3% | 174 277.3 0.0%
152000: 49 18.8 65.7% | 54 19.4 61.6% | 160 260.6 0.0%
153000: 47 19.3 61.7% | 49 19.3 62.0% | 176 282.8 0.0%
154000: 51 19.6 60.1% | 50 19.3 62.1% | 161 271.1 0.0%
155000: 53 19.3 62.0% | 59 19.2 63.0% | 177 274.9 0.0%
156000: 48 18.9 64.3% | 54 19.4 61.7% | 168 261.3 0.0%
157000: 51 19.0 63.9% | 63 19.4 61.2% | 146 246.0 0.0%
158000: 53 18.7 66.8% | 61 19.2 63.6% | 167 264.9 0.0%
159000: 50 19.5 60.9% | 48 18.8 65.9% | 181 277.3 0.0%
160000: 50 19.5 60.3% | 48 19.4 61.8% | 185 276.0 0.0%
161000: 52 19.6 60.9% | 51 19.9 57.3% | 171 266.4 0.0%
162000: 57 19.8 58.2% | 53 19.3 62.0% | 198 314.2 0.0%
163000: 57 20.3 55.2% | 51 19.1 63.6% | 222 321.8 0.0%
164000: 60 20.1 56.6% | 54 19.7 59.6% | 231 352.5 0.0%
165000: 50 19.6 59.8% | 52 19.5 60.8% | 239 360.1 0.0%
166000: 53 20.0 57.6% | 50 18.9 64.7% | 243 354.7 0.0%
167000: 49 19.6 59.6% | 49 19.3 61.4% | 256 367.5 0.0%
168000: 55 19.5 60.6% | 52 18.7 66.0% | 274 385.4 0.0%
169000: 49 19.0 63.9% | 51 19.4 61.4% | 287 411.4 0.0%
170000: 55 19.7 59.3% | 57 19.9 57.8% | 317 431.1 0.0%
171000: 51 18.9 65.4% | 53 19.4 61.7% | 315 431.3 0.0%
172000: 54 19.0 64.2% | 52 19.4 61.7% | 343 464.0 0.0%
173000: 53 19.1 63.7% | 55 19.7 59.4% | 368 492.9 0.0%
174000: 55 19.5 60.6% | 52 19.9 58.3% | 372 524.9 0.0%
175000: 52 18.9 64.8% | 48 19.4 61.3% | 400 551.9 0.0%
176000: 51 19.3 62.1% | 49 19.0 64.1% | 402 545.6 0.0%
177000: 56 19.3 62.4% | 52 20.0 57.0% | 424 579.0 0.0%
178000: 47 19.2 62.7% | 51 20.1 56.8% | 438 568.1 0.0%
179000: 57 19.3 62.2% | 48 19.2 63.0% | 458 602.1 0.0%
180000: 49 19.5 60.6% | 55 20.1 56.4% | 450 594.3 0.0%
181000: 57 19.4 61.7% | 52 19.1 63.5% | 457 596.0 0.0%
182000: 54 19.5 61.3% | 51 18.7 66.3% | 427 589.1 0.0%
183000: 52 19.1 63.3% | 48 19.0 63.8% | 467 617.2 0.0%
184000: 55 19.6 59.7% | 65 18.9 65.4% | 511 657.8 0.0%
185000: 54 19.3 62.2% | 48 18.9 65.5% | 456 615.2 0.0%
186000: 50 19.4 61.2% | 53 19.5 61.4% | 493 647.3 0.0%
187000: 50 18.8 65.1% | 49 18.6 67.2% | 463 631.2 0.0%
188000: 53 19.1 64.3% | 52 19.4 61.4% | 459 620.7 0.0%
189000: 51 19.1 63.6% | 52 19.8 58.7% | 448 654.5 0.0%
190000: 51 19.7 59.5% | 51 19.3 61.8% | 494 644.2 0.0%
191000: 54 18.9 64.8% | 51 19.3 61.7% | 491 647.2 0.0%
192000: 50 19.6 60.2% | 50 19.7 58.7% | 462 616.3 0.0%
193000: 50 18.9 64.4% | 53 18.8 65.9% | 506 646.8 0.0%
194000: 49 19.0 64.7% | 54 19.7 58.9% | 513 643.2 0.0%
195000: 51 19.1 63.2% | 47 19.7 59.1% | 441 594.4 0.0%
196000: 47 18.6 66.3% | 48 18.9 65.3% | 420 566.4 0.0%
197000: 56 19.5 60.9% | 51 19.3 62.3% | 417 571.9 0.0%
198000: 52 18.8 65.8% | 50 19.8 58.3% | 381 550.0 0.0%
199000: 56 19.6 60.0% | 58 19.5 60.9% | 416 551.4 0.0%
200000: 53 19.2 63.0% | 51 19.9 58.6% | 414 551.0 0.0%

After another 100,000 generations, we find that the median distance within populations A and B remained less than 20, just as we would expect given the selection pressures restricting reproduction to mating pairs with a distance of less than 20.

But the distance between A and B grew to a minimum of 414, and a median of 551. As expected, with no selective disadvantage for either population to diverge from the other population, the distance between the two populations continued to grow.

After one million generations, the mean distance between A and B grew to more than 7,000 (intra-population distances remained less than 20). There is no reason to think it won't continue to grow to the limits of what the simulation can accommodate.

magellan004

March 29th 2011, 12:22 PM

ericmurphy

March 29th 2011, 12:43 PM

'Houston, we have a problem.'
NASA Man - 'Stand by for the lectures on how it's Magellan's fault, Magellan's lack of understanding, Magellan's trollish behavior.'

As usual, Magellan looks to find any two statements by different individuals, and uses those differences to imply that his opponents can't agree with each other.

There's no practical distinction to be made between sylas's statement and mine, Magellan. The only difference is terminology. In my model, we have one ancestral population: X. Sylas's simulation refers to X differently, in order to simplify coding.

You apparently either missed this passage in sylas's post or could not puzzle out its significance:

Before the physical separation, the identification of groups has about as much significance as defining groups of humans based on whether their first name begins with A-M, or with N-Z. You can get all the statistics you like for the two groups, and that is what I did in the graphs provided.

If you think either one of us is saying anything other than that initially there is a single freely-interbreeding population, I'd like you to point me to where either us is saying something different. If you think there is some significance to the fact that I am referring to that single ancestral population as X and sylas is referring to it in his simulation as "A and B interbreeding together as a single population," I'd like to know what you think it is.

Run the simulation, Magellan. You can run it from the beginning as two separate populations which do not interbreed, or you can run it as a single population which later splits into two populations which do not interbreed. The results are the same in either case. The genomes within a population do not diverge beyond a strictly-defined limit. As soon as you have two populations which do not interbreed, their genomes begin to diverge until they are no longer interfertile.

Your incessant quibbling about definitions and nomenclature, none of which actually accomplishes anything other than injecting confusion and chaos into the debate, never grows less tiresome. In the meantime, you are either making no effort to understand my model and sylas's simulation of that model, or you are simply incapable of understanding it.

In either case, you are having zero success in actually constructing a criticism of either my model or sylas's simulation of it. I don't expect that situation ever to change.

Faid

March 29th 2011, 01:43 PM

ericmurphy

March 29th 2011, 02:10 PM

I just wonder what sense it makes, in the context of this discussion, to talk about "two groups...which did interbreed."

What is the distinction between A and B if both are interbreeding with each other? How are they separate groups? Are they "separate groups which are the same group"?

In my description of my model, I very specifically state that the initial condition is one, freely-interbreeding group. In sylas's simulation of my model, there is no practical distinction between A and B until the two populations are separated and prevented from interbreeding.

sylas

March 29th 2011, 02:15 PM

None of these is true, Magellan. Sylas's simulation, which is based on my model, has one group at the beginning: X. Just because, for the sake of programming sanity, it's not labeled that in the logic of his program doesn't change anything. You can run sylas's simulation with a single group for as many generations as you want, before you separate it into two groups.

There's a sensible reason why Eric and I gave different answers. To get the graph I gave previously, I took the simulation output, and plotted it in Excel. However, the way the simulation is written, data is given only for the whole population if no isolation has been imposed. To generate my graph, I had to make a little addition of my own to the code, and it isn't in the code I put up for everyone to use.

Hence Eric is quite correct about the simulation as given. The graph I got and displayed in the thread was from a slightly different program with one additional line of code.

In the code which has been made available, as soon as you specify groups, the groups don't interbreed. You can't get output for groups unless the groups are isolated.

The way it works in the code is this. All individuals are kept in one big array, called "PopArray".

If nP is the population size, then the individuals are kept as PopArray[0] up to PopArray[nP-1]

A group within P is defined by giving a number of individuals in the first group A. Call this nA. (Hence the number in group B is nB=nP-nA). Group A is then individuals PopArray[0] to PopArray[nA-1], and group B is individuals PopArray[nA] to PopArray[nP-1]

However, as soon as you give this number to the program, it immediately imposes geographical isolation. So you can't actually get the program to output group information for groups that interbreed.

I added a line of code to allow interbreeding between groups as long as the number of generations was less than 1000. This meant I could get output for my graph, in which I could display information about the groups before the isolation was imposed.

The next release will give all kinds of options for letting you get the output you want or try simple changes to the options. In particular, I will be considering allowing groups to change size, or have only partial mixing. There's going to be a lot more available to experiment with eventually, I hope.

Cheers -- sylas

ericmurphy

March 29th 2011, 02:29 PM

What's troubling about Magellan's questions about whether there are one, two, or possibly three populations initially is that I specified the initial conditions weeks ago, and those conditions have never changed. We have always started with a single, freely-interbreeding population. There has never been any question about that. It has always and ever been the case that it is only subsequently that that ancestral population is separated into two populations which do not interbreed.

It's difficult to imagine why Magellan would be feigning confusion on this point. He cannot possibly really be confused on this point.

magellan004

March 29th 2011, 03:42 PM

And by the way, Magellan: in sylas's model, fertility is always 100% or zero, as you measure it. A couple either produces offspring or it doesn't. Using the default values, genetic differences of less than 61 always produce offspring; differences greater than 60 never produce offspring. The result is this graph:

http://www.planet-deepblu.com/~eric/graphic_links/FirstNonInterfertileLine.png

So—even if it were true that an individuals' fertility could only be 100% or zero, we still get speciation.

Two comments on your graph.
1. The right vertical axis (% Interfertility ) makes no sense.
2. Your conclusion that there is a relationship between your graph , a variable fertility rates and Speciation doesn't seem to follow.

Here is some dummy data.
Let's assume that 60 differences = Able to interbreed
61 Differences = Unable to interbreed.

Population size = 11
Individual 1 has 58 differences
Ind 2 = 58 diff
Ind 3 = 59 diff
Ind 4 = 59 diff
Ind 5 = 59 diff
Ind 6 = 60 diff
Ind 7 = 60 diff
Ind 8 = 60 diff
Ind 9 = 61 diff
Ind 10 = 61 diff
Ind 11 = 62 diff

Can you plot that data onto your graph - in particular using the right hand axis
'Interfertility %' and bottom axis 'No of Dofferences '?

Thanks

Magellan

ericmurphy

March 29th 2011, 04:20 PM

Two comments on your graph.
1. The right vertical axis (% Interfertility ) makes no sense.
Of course it makes sense. It relates interfertility to number of differences. Above a certain number of differences, indicated by the blue line (the one with the red circle around its tip), interfertility drops from 100% to zero.

This is like the sixth time I've explained this to you.

2. Your conclusion that there is a relationship between your graph , a variable fertility rates and Speciation doesn't seem to follow.

That's because this graph does not indicate variable fertility rates. It has two rates—100% and zero—with no intermediate rates at all.

And before you say, "yes it does show variable interfertility rates—look at the green curve!"—I will point out once again that the green curve has nothing to do with interfertility. It simply shows the distribution of numbers of differences members of one population have wrt members of the other population. The left-hand scale, "number of individuals," applies to the green curve. Not the right-hand scale. The right-hand scale applies to the blue interfertility curve.

Here is some dummy data.
Let's assume that 60 differences = Able to interbreed
61 Differences = Unable to interbreed.

Population size = 11
Individual 1 has 58 differences
Ind 2 = 58 diff
Ind 3 = 59 diff
Ind 4 = 59 diff
Ind 5 = 59 diff
Ind 6 = 60 diff
Ind 7 = 60 diff
Ind 8 = 60 diff
Ind 9 = 61 diff
Ind 10 = 61 diff
Ind 11 = 62 diff

Can you plot that data onto your graph - in particular using the right hand axis
'Interfertility %' and bottom axis 'No of Dofferences '?

Thanks

No need. Sylas has already done this graph:

https://lh4.googleusercontent.com/_WtnYwFZtgHI/TZBSB0F0sUI/AAAAAAAAJ74/GDGuG115G_U/s640/Fertility.jpg

Using your own starting conditions, you'll get what is plotted on my graph: differences greater than 60 result in interfertility suddenly dropping from 100% to zero. Sylas's green trace is not the perfect vertical line my blue trace is, because my trace is based on idealized data, whereas his is the result of actual random mutations to his virtual organisms, which adds noise to the curve.

You still seem obsessed with the idea that speciation cannot happen if individual interfertility can only be total or zero. I have demonstrated time and again this is simply not true. Sylas's entire simulation, which assumes that individual interfertility can only be total or zero, still results in speciation, no matter what numbers you use for the allowable number of differences that still allow interfertility.

My graph does not have any particular number of differences on it, just greater or lesser differences depending on where on the X axis you look. As has been pointed out to you over and over again, my model is a very general model of speciation which does not depend on specific quantitative measures. But the validity of the model is demonstrated by the fact that whatever numbers you do use, for fertility limits, population sizes, number of mutations per generation, etc., you get the same results: shortly after reproductive isolation, you end up with two species which cannot interbreed.

If you want representative numbers for this, read post 1399 (http://www.theologyweb.com/campus/showthread.php?144614-Evolution-of-The-Beetles&p=3200384#post3200384). In the simulation run I provided the data for, within 3,000 generations from the initial reproductive isolation, interfertility between populations (measured as the proportion of mates in one population which can produce viable offspring with any member of the other population) drops from 64% to zero, and stays there for the next 97,000 generations.

magellan004

March 29th 2011, 05:15 PM

Of course it makes sense. It relates interfertility to number of differences. Above a certain number of differences, indicated by the blue line (the one with the red circle around its tip), interfertility drops from 100% to zero.

This is like the sixth time I've explained this to you.

That's because this graph does not indicate variable fertility rates. It has two rates—100% and zero—with no intermediate rates at all.

And before you say, "yes it does show variable interfertility rates—look at the green curve!"—I will point out once again that the green curve has nothing to do with interfertility. It simply shows the distribution of numbers of differences members of one population have wrt members of the other population. The left-hand scale, "number of individuals," applies to the green curve. Not the right-hand scale. The right-hand scale applies to the blue interfertility curve.

No need. Sylas has already done this graph:

https://lh4.googleusercontent.com/_WtnYwFZtgHI/TZBSB0F0sUI/AAAAAAAAJ74/GDGuG115G_U/s640/Fertility.jpg

Using your own starting conditions, you'll get what is plotted on my graph: differences greater than 60 result in interfertility suddenly dropping from 100% to zero. Sylas's green trace is not the perfect vertical line my blue trace is, because my trace is based on idealized data, whereas his is the result of actual random mutations to his virtual organisms, which adds noise to the curve.

You still seem obsessed with the idea that speciation cannot happen if individual interfertility can only be total or zero. I have demonstrated time and again this is simply not true. Sylas's entire simulation, which assumes that individual interfertility can only be total or zero, still results in speciation, no matter what numbers you use for the allowable number of differences that still allow interfertility.

My graph does not have any particular number of differences on it, just greater or lesser differences depending on where on the X axis you look. As has been pointed out to you over and over again, my model is a very general model of speciation which does not depend on specific quantitative measures. But the validity of the model is demonstrated by the fact that whatever numbers you do use, for fertility limits, population sizes, number of mutations per generation, etc., you get the same results: shortly after reproductive isolation, you end up with two species which cannot interbreed.

If you want representative numbers for this, read post 1399 (http://www.theologyweb.com/campus/showthread.php?144614-Evolution-of-The-Beetles&p=3200384#post3200384). In the simulation run I provided the data for, within 3,000 generations from the initial reproductive isolation, interfertility between populations (measured as the proportion of mates in one population which can produce viable offspring with any member of the other population) drops from 64% to zero, and stays there for the next 97,000 generations.

Here- I've fixed up your graph.

Magellan

Faid

March 29th 2011, 05:29 PM

Here Mags, I fixed your graph.

ericmurphy

March 29th 2011, 05:31 PM

Here is some dummy data.
Let's assume that 60 differences = Able to interbreed
61 Differences = Unable to interbreed.

Population size = 11
Individual 1 has 58 differences
Ind 2 = 58 diff
Ind 3 = 59 diff
Ind 4 = 59 diff
Ind 5 = 59 diff
Ind 6 = 60 diff
Ind 7 = 60 diff
Ind 8 = 60 diff
Ind 9 = 61 diff
Ind 10 = 61 diff
Ind 11 = 62 diff

Can you plot that data onto your graph - in particular using the right hand axis
'Interfertility %' and bottom axis 'No of Dofferences '?

Actually, taking this portion at face value, here's your graph of interfertility vs. number of differences. I would have thought you'd be able to derive it yourself, but apparently not:

http://www.planet-deepblu.com/~eric/graphic_links/60%20differences.png

I don't know where you think the individuals should go. The graph, as you've requested it, has interfertility plotted against number of differences. Where would individuals go on such a graph?

ericmurphy

March 29th 2011, 05:32 PM

Here- I've fixed up your graph.

Magellan

It doesn't look "fixed" to me. It looks like you took my graph and did a crude re-drawing of it.

In terms of content, there's no difference. In terms of aesthetics…

ETA: I sort of got the impression that Magellan's objection to my diagram was mainly that it didn't have enough numbers on it. But his "fix" to my diagram doesn't have any numbers on it that aren't on my graph, so I'm at a loss as to why he thinks he "fixed" anything.

magellan004

March 29th 2011, 07:36 PM

It doesn't look "fixed" to me. It looks like you took my graph and did a crude re-drawing of it.

In terms of content, there's no difference. In terms of aesthetics…

ETA: I sort of got the impression that Magellan's objection to my diagram was mainly that it didn't have enough numbers on it. But his "fix" to my diagram doesn't have any numbers on it that aren't on my graph, so I'm at a loss as to why he thinks he "fixed" anything.

Your new, revised graph (which was provided free of charge) has 1. A legend, 2. A continuous function for interfertility (yours cut out at an arbitrary 'no of distances' and 3. There is no area under the bell curve (because that area seemed to represent nothing)

A roughly drawn diagram that conveys meaning is surely better than a flashy diagram that causes confusion.

Magellan

ericmurphy

March 29th 2011, 07:48 PM

Your new, revised graph (which was provided free of charge) has 1. A legend,
My chart already has a legend:

http://www.planet-deepblu.com/~eric/graphic_links/FirstNonInterfertile.png

All you did was duplicate the axis labels. And you're charging for your "improved" chart exactly what it is worth.

2. A continuous function for interfertility (yours cut out at an arbitrary 'no of distances'

Hey, you're the one who's been insisting on interfertility always being only 100% or zero, and your function for interfertility is no less arbitrary than mine is. In fact, it's identical to mine.

and 3. There is no area under the bell curve (because that area seemed to represent nothing)

It represents exactly the same thing in your chart as mine: the number of individuals with a particular number of differences. Removing the shading under your curve doesn't remove the area under it.

Your chart is in all respects (other than competence of execution) identical to mine.

A roughly drawn diagram that conveys meaning is surely better than a flashy diagram that causes confusion.

There is no "meaning" in your diagram that isn't also in mine. I'm left with the distinct impression that you have no greater of an understanding of your own chart than you do of mine

ericmurphy

March 29th 2011, 09:26 PM

Magellan doesn't like it when I use mysterious, esoteric terms like "fertility," or "population," or "fixation." He complains that my illustrations don't have enough words and/or numbers on them. He doesn't like my color choices.

But can he frame a coherent criticism of my model?

Not so much.

magellan004

March 30th 2011, 01:22 AM

ericmurphy

March 30th 2011, 01:31 AM

'Confusing' is not a far step away from incorrect.

When it's "confusing" to you it sure is.

So far you've been less than effective at finding anything "incorrect" about anything I've said, Magellan. And you still haven't explained how it is that I could predict so many aspects of sylas's simulation before he even wrote it. How is it, for example, that the curve generated here:

https://lh4.googleusercontent.com/_WtnYwFZtgHI/TZBSB0F0sUI/AAAAAAAAJ74/GDGuG115G_U/s640/Fertility.jpg

Looks so much like the curve I drew here:

http://www.planet-deepblu.com/~eric/graphic_links/SpeciesCurve.png

Coincidence?

ETA: Have you even managed to run sylas's simulation yet? Do you have any comments on how closely its output matches the predictions my model makes?

sylas

March 30th 2011, 01:32 AM

'Confusing' is not a far step away from incorrect.

Not here it isn't. That approximation doesn't work when there's only one person who is confused.

In this thread, the problem is not that everyone except you is incorrect. It is that either you are a poor student, or we don't have any good teachers in the discussion. The truth is a bit of both, and I really don't care all that much how people want to allocate blame. You can guess what I think; but it really doesn't matter.

I'll keep explaining as best I can, as long as I think there may be some point to it.

Cheers -- sylas

magellan004

March 30th 2011, 02:54 AM

Not here it isn't. That approximation doesn't work when there's only one person who is confused.

In this thread, the problem is not that everyone except you is incorrect. It is that either you are a poor student, or we don't have any good teachers in the discussion. The truth is a bit of both, and I really don't care all that much how people want to allocate blame. You can guess what I think; but it really doesn't matter.

I'll keep explaining as best I can, as long as I think there may be some point to it.

Cheers -- sylas

Good. The insult and put-downs are not very interesting except for a short energy burst. When I get insults thrown at me I feel the urge to swat away - much like you , I'm sure.

You are at your best when you are explaining stuff. That I like.

I had this thought while driving home this afternoon -

As I understand it -
One of the things your simulation does is it recycles children's differences so that a child's particular difference ends up in the general 'difference pool ' of the group. In fact there are no identifiable differences (such a a trait).

So for example if a child mutated 'wings' (don't freak out, it's only an example) then that child would not have a traceable family line.

You model is based on the premise that the gain of an ability or feature, or the loss of an ability (such as ability to interbreed with X' is purely a reflection of genetic distance.

Another hypothetical example - evolutionists may say that a bird and a kangaroo are equidistant from a snail, but only one of them can fly.

I have been wondering whether it would be possible or too big a task to be able to step through your model to follow a family line from any first child. I know this was talked about early on.

But I think it might make the programming too complicated.

I'm away for a few days - see you all soon.

Magellan

Faid

March 30th 2011, 04:19 AM

'Confusing' is not a far step away from incorrect.

Magellan
Only to the terminally confused.

phaedrus

April 1st 2011, 07:42 PM

Blissfully serene in here, isn't it. Anyone for a glass of wine?

rogue06

April 1st 2011, 08:20 PM

I think today is a religious holiday for m004.

magellan004

April 2nd 2011, 12:03 AM

Anyone for a friendly discussion about science?

Magellan

Tiggy

April 2nd 2011, 07:39 AM

Anyone for a friendly discussion about science?

Magellan

Sure thing Clownshoes. Do you know someone who can discuss it intelligently?

- T

Astra49

April 3rd 2011, 01:52 AM

Blissfully serene in here, isn't it. Anyone for a glass of wine?

Martini please, and hold the ice !!!!
Feels icy cold here!

And here I was really enjoying the sabre rattling from one and all and learning much about specation, fertility, populations and genetic distances etc. It has been very interesting.

ericmurphy

April 4th 2011, 10:30 AM

Looks like Magellan has given up trying to teach us all about evolution. And how it doesn't work.

magellan004

April 6th 2011, 01:10 AM

Here is my computer simulation of Speciation.
It is written in Microsoft Small Basic and to execute it you will have to download the Microsoft program - Microsoft Small Basic download -
http://www.microsoft.com/downloads/en/details.aspx?FamilyID=b006d58d-c2c7-44ad-936b-e7e2d7de793e
With large numbers for generations and populations it executes slowly so be patient. Try small numbers first to satisfy yourself it works. It may have bugs. I have done quite a few tests and the code is full of my commented out diagnostic messages.

Small Basic is fairly easy to come to grips with. If you are not sure about anything I will hopefully be able to answer. Unfortunately the output appears in a console screen and I
don't know how to save that form of output so I can't give screen shots of the tests and results.

The idea of my simulation is simple -
1. There is an initial population.
2. The population splits and
3. In Group B the first generation includes an individual who cannot breed with Group A. This individual is a "Type X individual'. The parents were Type N.
4. Any 'Type N' individuals can breed with Group A.
5. All parent pairs have 2 children.
6. If a parent pair includes a Type X individual then a child has a 50/50 chance of being a Type X individual.
7. Parents breed once then the program starts again and those former children become the parent generation.

That means that the first Type X individual has to be the ancestor of any subsequent Type X individuals.

At the end of the simulation if any Type N's still exist then Speciation has not occurred.

In the tests I have run, no matter the size of the population or the number of generations, Speciation does not occur.

Give it a whirl!

Magellan

ericmurphy

April 6th 2011, 01:36 AM

Guess what, Magellan?

It doesn't matter whether or not speciation occurs in your "model."

It does occur in my model, and in sylas's computer simulation of my model.

How many times am I going to have to say it? It doesn't matter how many bad, wrong, broken "models" you come up with in which speciation doesn't happen. Where, for your example, do you even test whether the two populations can interbreed? Whether or not any "type Ns" still exist is meaningless. It has nothing to do with anything. Where does mutation occur? What factors result in interfertility or its lack? Those are all features of realistic models of speciation, and they seem to be totally lacking in your "model."

No surprise that speciation won't happen. A program that generates the value of pi to two thousand decimal places won't result in speciation, either.

And by the way: you already know I'm running OS X. Why would you even waste your time posting a non-cross-platform if you were honestly interested in my evaluation of it?

And in the meantime, you're still stuck. Until you can explain why my model, and sylas's simulation based on that model, which does result in speciation, is somehow "wrong," you're not going to get anywhere.

Whether or not your "model" results in speciation is utterly irrelevant.

sylas

April 6th 2011, 04:52 AM

Here is my computer simulation of Speciation.

Irrelevant. You wanted to know about evolution. If you want to understand evolutionary theory and evolution models, you need to look at the models used by scientists. Not invent something for yourself.

To the extent that you think this has anything whatever do to with evolution, you continue to show, as you have done throughout the thread, that you don't even understand what you purport to criticize.

Understand. THEN criticize.

(I think you have been given this advice before.)

Cheers -- sylas

(PS. I am still going on EvoSim v2. Got side tracked a bit, but I back on it again now.)

magellan004

April 6th 2011, 07:51 AM

Irrelevant. You wanted to know about evolution. If you want to understand evolutionary theory and evolution models, you need to look at the models used by scientists. Not invent something for yourself.

To the extent that you think this has anything whatever do to with evolution, you continue to show, as you have done throughout the thread, that you don't even understand what you purport to criticize.

Understand. THEN criticize.

(I think you have been given this advice before.)

Cheers -- sylas

(PS. I am still going on EvoSim v2. Got side tracked a bit, but I back on it again now.)

I do understand that you say that something which shows how evolution cannot work is irrelevant to you. You need to 'make noises'. Of course you do.
I also understand how relevant it is to you.

The situation is no different to me giving bitter medicine to a sick child.

You will be better off if you come to terms with it.

Magellan

sylas

April 6th 2011, 09:25 AM

I do understand that you say that something which shows how evolution cannot work is irrelevant to you.

That is another example of you being deliberately dense, and deliberately dishonest. You are merely playing with words and distorting the discussion with stuff you know is inaccurate. It's contemptible.

I did NOT say that "something which shows how evolution cannot work is irrelevant". I said nothing at all about "working" or "not working". What I said is that your model is irrelevant to a discussion of evolution because whether it works or not, it simply isn't using the models of evolution, but something else.

All you are showing above is a lack of respect for me, and for the discussion.

When you stop playing silly games, and get back to an honest attempt at looking the answers to serious questions about evolutionary models, then I'll be happy to take it up again. I do this with no requirement that you actually believe evolutionary models are accurate, and with no requirement that you have to believe that species evolve and speciate and diverge in nature. Disagreement is fine. Twisting the other person's words is NOT. So stop it.

A point about simulations. My simulation, and your simulation, are both equally unable to stand as "proof" or "disproof" of evolution. They are far too simple.

What a simulation can do, however, is help explain a model. My simulation is helping to explain the model that Eric has presented. Your simulation is helping to explain something different, something of your own invention.

If you were serious, I would be willing to go through your program and pull out more precisely where it differs from the models used in evolution. But that would presume you were actually genuine in asking about what the evolutionary model actually involves. Posts like the above show you are not.

For what it is worth, the version 2 of EvoSim that I am working on, and have nearly finished, has an added capacity to trace ancestry, which you had earlier asked about. This doesn't modify the simulation of mating and fertility used; but simply adds a capacity to keep track of the parents of each individual, and also of ancestry from some group in the past.

A serious criticism of my model would need to show where the model actually fails to represent evolutionary ideas correctly, and where it fails to capture aspects of living things in nature. I have already listed many aspects of natural biology which it fails to capture; and hence it cannot be used to "predict" anything in nature. It's not biology; it is only a distillation into code of the basic features of biology which are invoked to explain allopatric speciation, in the model Eric has set out in more general terms.

Sylas -- disgusted.

sylas

April 6th 2011, 10:00 AM

1. There is an initial population.
2. The population splits and
3. In Group B the first generation includes an individual who cannot breed with Group A. This individual is a "Type X individual'. The parents were Type N.
4. Any 'Type N' individuals can breed with Group A.
5. All parent pairs have 2 children.
6. If a parent pair includes a Type X individual then a child has a 50/50 chance of being a Type X individual.
7. Parents breed once then the program starts again and those former children become the parent generation.

Here is a serious comment on the above algorithm.

Suppose that instead of starting with one "X" individual, you start with ALL individuals being "X". That is, you start from a generation where you already have "speciation" in the sense of no "N" individuals.

When you run the algorithm, it will in a single generation give you half the individuals being type "X" and half being type "N". In other words, if you start this algorithm with a generation that is speciated, then the next step will ensure it is not speciated anymore. That is precisely what happens with your code.

There's another problem also. The program proposes that the initial group B and group A were geographically split. In that case, the two populations for group A and group B should be, initially, the same. That is, if the new X can't mate with group A, then it won't mate with group B either -- and will die out at once.

In the tests I have run, no matter the size of the population or the number of generations, Speciation does not occur.

Yes; and as I have shown, even if "speciation" DOES occur in some generation in your simulation, then the chance of the next generation being STILL speciated will be 0.5^popsize. So what you are calling "speciation" has this crucial difference with biology. In biology, group B is a different species to group A, then the next generation of group B will still be a different species. In your model, a group B which you call "speciated" has only about a 1 in a million chance of still being speciated in the next generation (assuming a population size of 20).

Sylas

PS. The code is also uses a deterministic algorithm for mating. Each individual has a number from 1 to P. They are mated, so that i+j = P+1. That is, 1 mates with P, 2 mates with P-1, 3 mates with P-2, etc. The children of (i,j) are located at 2i and 2i-1. A random mating scheme is better in models like this, to avoid having unintended consequences of a deterministic scheme feeding into results. However, the main problem is the one listed above.

ericmurphy

April 6th 2011, 10:38 AM

I do understand that you say that something which shows how evolution cannot work is irrelevant to you.
Your "simulation" doesn't show evolution cannot work, Magellan. It shows that your bad, wrong, broken, poorly-conceived strawman version of evolution cannot work.

That's not the same thing.

Your "simulation," if it "simulates" anything at all, simulates the fixation of a single mutation throughout a population. Population genetics tells us that the probability of a particular mutation going to fixation is roughly the same as its proportion in that population. Not having run your "simulation" (I can't be bothered tracking down a BASIC interpreter for OS X to run a single program that doesn't do what its programmer says it does anyway), it looks like you've got a single mutation initially present in one percent of a population, which means it has roughly a 1% chance of going to fixation. But it looks like your "simulation" runs through a few hundred generations at most. The chances of any mutation going to fixation in a few hundred generations is effectively zero unless it's already present in a majority of a population.

And, of course, there are no other mutations, occurring, the mutation only occurs in a single population, and therefore we're expected to believe that a single mutation, and only a single mutation, can ever be the cause of speciation. Small wonder Magellan doesn't observe speciation in a "simulation" that is guaranteed not to result in speciation.

sylas

April 6th 2011, 10:51 AM

Your "simulation," if it "simulates" anything at all, simulates the fixation of a single mutation throughout a population. ...

At first glance, I thought that might be a possibility. But it isn't. In Magellan's model, a population that is pure "X" will be about half "X" and half "N" in the next generation. It is impossible even to represent fixation, in his model.

To model fixation, you would need to have parents that are both X to have only X descendants.

One way to improve Magellan's model would be as follows.

The children of parents will be a copy of either one parent, or the other, chosen at random.

In this case, "X" and "N" are now on an equivalent footing. Two X parents can only have X children. Two N parents can only have N children. Mixed parents will have their children as either X or N, each child chosen at random. This is close to what happens in biology, if we identify individuals with the haploid gametes rather than with the diploid adults. Managing diploidy explicitly is left as an exercise for the reader... and it is also something that may show up in version 3 of my own simulation.

To get a representation of Dobzhansky-Muller reproductive isolation, which I described in an earlier post, you would need each individual to be represented as two sequences of letters (a sequence being like a chomosome) and then have children formed by taking a letter at each point at random from one parent or the other. Infertility occurs when the number of places at which there are different letters being above a certain bound. Mutation would be random introduction of new letters from time to time -- but only very rarely! In this model a mutation is always deleterious.

Something more to consider for EvoSim version 3.

Cheers -- sylas

ericmurphy

April 6th 2011, 10:58 AM

Criticisms of Magellan's "simulation" by others:

Does not allow for more than one mutation, ever
Does not simulate genetic drift, a critical element in any model of speciation
The one allowed mutation should prevent interfertility with either population, not just one population
Since that mutation only has a 50% chance of being inherited, even if it is present in both parents, it cannot go to fixation
The mating method is deterministic
Runs too slowly to complete a realistic number of generations (tens of thousands to millions)
Does not resemble any actual model of speciation used in evolutionary theory

Criticism of sylas's simulation by Magellan:

…

magellan004

April 7th 2011, 06:54 AM

That is another example of you being deliberately dense, and deliberately dishonest. You are merely playing with words and distorting the discussion with stuff you know is inaccurate. It's contemptible.

I did NOT say that "something which shows how evolution cannot work is irrelevant". I said nothing at all about "working" or "not working". What I said is that your model is irrelevant to a discussion of evolution because whether it works or not, it simply isn't using the models of evolution, but something else.

All you are showing above is a lack of respect for me, and for the discussion.

When you stop playing silly games, and get back to an honest attempt at looking the answers to serious questions about evolutionary models, then I'll be happy to take it up again. I do this with no requirement that you actually believe evolutionary models are accurate, and with no requirement that you have to believe that species evolve and speciate and diverge in nature. Disagreement is fine. Twisting the other person's words is NOT. So stop it.

A point about simulations. My simulation, and your simulation, are both equally unable to stand as "proof" or "disproof" of evolution. They are far too simple.

What a simulation can do, however, is help explain a model. My simulation is helping to explain the model that Eric has presented. Your simulation is helping to explain something different, something of your own invention.

If you were serious, I would be willing to go through your program and pull out more precisely where it differs from the models used in evolution. But that would presume you were actually genuine in asking about what the evolutionary model actually involves. Posts like the above show you are not.

For what it is worth, the version 2 of EvoSim that I am working on, and have nearly finished, has an added capacity to trace ancestry, which you had earlier asked about. This doesn't modify the simulation of mating and fertility used; but simply adds a capacity to keep track of the parents of each individual, and also of ancestry from some group in the past.

A serious criticism of my model would need to show where the model actually fails to represent evolutionary ideas correctly, and where it fails to capture aspects of living things in nature. I have already listed many aspects of natural biology which it fails to capture; and hence it cannot be used to "predict" anything in nature. It's not biology; it is only a distillation into code of the basic features of biology which are invoked to explain allopatric speciation, in the model Eric has set out in more general terms.

Sylas -- disgusted.

I am trying a new format of reply using numbered paragraphs and replying without breaking up the questions. This is in a desperate attempt to circumvent Eric’s penchant for replying to each sentence without reading the rest of my post.

1. I am aware that my model of evolution is not a rehash of flawed models that already exist. I have no ambitions to mimicry.

2. I have respect for you. I need to constantly remind you that your editorials do not become you. I am sure that both of us advise each other in good faith.

3. You dismissed my model as irrelevant and continue to discuss it. Let me be the judge of what is relevant in this thread. Things will be irrelevant to you the day you stop contributing to this thread. Irrelevance is such a personal thing.

4. No. A model can show that the general principle is sound or flawed.

5. I am not sure what the difference is between a simulation and a model. A simulation is a model. Both/either/each is attempting to do one thing – Show the principles at work.

6. I am not interested in you comparing my model with flawed models. My model deals with the consequences of evolution. An example might help –

Let’s say that some physicists have been using a round bucket and a stirring stick to model ocean waves. Along comes Magellan with a wave tank. Sylas says – ‘Your wave tank does not represent the bucket model so well used and loved by previous experts.’

7. The ability to track ancestry might be useful.

8. One problem I see is that in your model there are no traits/characters.
Another problem is that in nature organisms do not evolve into different types of animals. A horse will always be a horse. A horse always was a horse. An Orca is just an Orca.

9. Try to remain in control or your emotions. After all, it’s just science.

Magellan

phaedrus

April 7th 2011, 07:40 AM

http://i775.photobucket.com/albums/yy32/Sonicbowling/TROLL.jpg

ericmurphy

April 7th 2011, 10:31 AM

I am trying a new format of reply using numbered paragraphs and replying without breaking up the questions. This is in a desperate attempt to circumvent Eric’s penchant for replying to each sentence without reading the rest of my post.

1. I am aware that my model of evolution is not a rehash of flawed models that already exist. I have no ambitions to mimicry.

Wow.

First, you haven't identified any "flaws" in the already-existing models. You haven't even tried to identify any "flaws." It's pretty clear you don't even understand the model under discussion here to identify any "flaws" in it.

Second, it still makes no sense that you would even try to model a process you claim doesn't exist in the first place. That's like me making a model of how the earth could be flat.

2. I have respect for you. I need to constantly remind you that your editorials do not become you. I am sure that both of us advise each other in good faith.

I have extreme doubts about any "good faith" on your part, Magellan. You are without question one of the least intellectually honest creationists I've ever dealt with. That's not an insult; it's a simple observation.

3. You dismissed my model as irrelevant and continue to discuss it. Let me be the judge of what is relevant in this thread. Things will be irrelevant to you the day you stop contributing to this thread. Irrelevance is such a personal thing.

Your model is irrelevant to evolutionary theory. It bears no resemblance to evolutionary theory, and hence any flaws in your model (and they are legion) do not impinge on the accuracy of evolutionary theory in the slightest.

4. No. A model can show that the general principle is sound or flawed.

Your model is flawed. Deeply flawed. Whatever "principle" you think it illustrates is therefore also flawed. Unfortunately for you, since it bears no resemblance to evolutionary theory, it does not, and cannot, illustrate any flaws in evolutionary theory.

5. I am not sure what the difference is between a simulation and a model. A simulation is a model. Both/either/each is attempting to do one thing – Show the principles at work.

A simulation is a concrete implementation of a model.

6. I am not interested in you comparing my model with flawed models. My model deals with the consequences of evolution. An example might help –

Your model has nothing to do with evolution. Evolution doesn't even occur under your model.

Let’s say that some physicists have been using a round bucket and a stirring stick to model ocean waves. Along comes Magellan with a wave tank. Sylas says – ‘Your wave tank does not represent the bucket model so well used and loved by previous experts.’

7. The ability to track ancestry might be useful.

Fortunately, we already have methods to track ancestry. Such as cladistic analysis.

8. One problem I see is that in your model there are no traits/characters.
What do you suppose the genomes of these virtual organisms are? And where are the traits/characters in your model? Your organisms do not even seem to have genomes.

Another problem is that in nature organisms do not evolve into different types of animals. A horse will always be a horse. A horse always was a horse. An Orca is just an Orca.

Well, how is that a problem, Magellan? Common descent says exactly that. A primate's descendants will always be primates. A mammal's descendants will always be mammals. A vertebrate's descendants will always be vertebrates. Were you under the impression that evolutionary theory said something different?

9. Try to remain in control or your emotions. After all, it’s just science.

It might be constructive for you to stop trying to guess at the emotions of others.

ericmurphy

April 7th 2011, 10:32 AM

Still no word from Magellan on what these supposed "flaws" are in my model.

rogue06

April 7th 2011, 11:20 AM

I am trying a new format of reply using numbered paragraphs and replying without breaking up the questions. This is in a desperate attempt to circumvent Eric’s penchant for replying to each sentence without reading the rest of my post.
It is what's known as a point-by-point refutation. And don't assume your post wasn't read before being dismantled in such a fashion.

rogue06

April 7th 2011, 11:29 AM

Another problem is that in nature organisms do not evolve into different types of animals. A horse will always be a horse. A horse always was a horse. An Orca is just an Orca.

Well, how is that a problem, Magellan? Common descent says exactly that. A primate's descendants will always be primates. A mammal's descendants will always be mammals. A vertebrate's descendants will always be vertebrates. Were you under the impression that evolutionary theory said something different?
Has it ever occurred to m004 to work the other way? Back to when horses diverged from the archaic ungulates for instance. An ungulate still always gives birth to an ungulate but we can see the various lineages of ungulates split apart in the fossil record.

ericmurphy

April 7th 2011, 11:44 AM

It is what's known as a point-by-point refutation. And don't assume your post wasn't read before being dismantled in such a fashion.

The only parts of Magellan's posts I ever don't reply to are those which a) are irrelevant to the topic being discussed, and/or b) those parts which are self-refuting.

Meanwhile, Magellan leaves entire posts of mine entirely un-responded to. He still hasn't responded to my initial post on his "model." (http://www.theologyweb.com/campus/showthread.php?144614-Evolution-of-The-Beetles&p=3204721#post3204721)

magellan004

April 7th 2011, 05:13 PM

Here is a serious comment on the above algorithm.

1. Suppose that instead of starting with one "X" individual, you start with ALL individuals being "X". That is, you start from a generation where you already have "speciation" in the sense of no "N" individuals.

2. When you run the algorithm, it will in a single generation give you half the individuals being type "X" and half being type "N". In other words, if you start this algorithm with a generation that is speciated, then the next step will ensure it is not speciated anymore. That is precisely what happens with your code.

3. There's another problem also. The program proposes that the initial group B and group A were geographically split. In that case, the two populations for group A and group B should be, initially, the same. That is, if the new X can't mate with group A, then it won't mate with group B either -- and will die out at once.

4. Yes; and as I have shown, even if "speciation" DOES occur in some generation in your simulation, then the chance of the next generation being STILL speciated will be 0.5^popsize. So what you are calling "speciation" has this crucial difference with biology. In biology, group B is a different species to group A, then the next generation of group B will still be a different species. In your model, a group B which you call "speciated" has only about a 1 in a million chance of still being speciated in the next generation (assuming a population size of 20).

Sylas

5. PS. The code is also uses a deterministic algorithm for mating. Each individual has a number from 1 to P. They are mated, so that i+j = P+1. That is, 1 mates with P, 2 mates with P-1, 3 mates with P-2, etc. The children of (i,j) are located at 2i and 2i-1. A random mating scheme is better in models like this, to avoid having unintended consequences of a deterministic scheme feeding into results. However, the main problem is the one listed above.

1. It would be sort of stupid to start showing how speciation occurs by starting with speciation having already occurred.

2. That is a problem for speciation, not my model. There is no point starting with two groups already being speciated. My model shows how (you cannot) get there. The process (presumably) starts with an individual. Giving birth to such an individual (a Type X) has consequences.

3. You have just outlined a major problem with speciation. You can’t just gloss over this initial problem of a ‘mutant’ child being unable to mate with some obscure group when it has to be able to mate with its own group. I spoke to Eric about this ages ago. His response was ‘Why can’t the parent give birth to Type X and Type N children?’

4. This I just reinforcing the problem with evolution. You can’t get to the end because the start of the process is unworkable.

5. In my model the children of each parent pair are allocated to different positions in the array (to the parents) so each generation is reordered as far as X and N go. I doubt that any other ordering would produce a different result and I could change it to some other system if you liked.

Thank you for your feedback.

Magellan

magellan004

April 7th 2011, 05:28 PM

Your "simulation" doesn't show evolution cannot work, Magellan. It shows that your bad, wrong, broken, poorly-conceived strawman version of evolution cannot work.

That's not the same thing.

Your "simulation," if it "simulates" anything at all, simulates the fixation of a single mutation throughout a population. Population genetics tells us that the probability of a particular mutation going to fixation is roughly the same as its proportion in that population. Not having run your "simulation" (I can't be bothered tracking down a BASIC interpreter for OS X to run a single program that doesn't do what its programmer says it does anyway), it looks like you've got a single mutation initially present in one percent of a population, which means it has roughly a 1% chance of going to fixation. But it looks like your "simulation" runs through a few hundred generations at most. The chances of any mutation going to fixation in a few hundred generations is effectively zero unless it's already present in a majority of a population.

And, of course, there are no other mutations, occurring, the mutation only occurs in a single population, and therefore we're expected to believe that a single mutation, and only a single mutation, can ever be the cause of speciation. Small wonder Magellan doesn't observe speciation in a "simulation" that is guaranteed not to result in speciation.

My model doesn’t specifically deal with mutations. It deals with whatever it is that makes one individual different as far as ability to interbreed . It could be a mutation, it could be many mutations. It could be a trait, it could be many traits. Unlike you , I am not using a ‘black-box’ where the magician puts several interbreeding animals into a hat, waves a wand an pulls out speciated populations.

Population genetics is based on evolutionary assumptions - hardly the way to investigate whether evolutionary processes actually work. But it looks like you will never grasp the the idea of begging the question.

In my model the starting point is the first individual that cannot interbreed with Group A – not a percentage of the population. The sad thing for evolution is that my model shows you can’t ever get to a percentage of the population with that feature (inability to interbreed) unless you make assumptions that negate speciation. As long as a TYPE X can have ‘normal’ children, speciation won’t happen. I warned you about this.
In other words, my model shows that ‘fixation’ is a fantasy.

And you will probably reply ‘Fixation does happen because without it you can’t have speciation.’

Magellan

ericmurphy

April 7th 2011, 05:45 PM

My model doesn’t specifically deal with mutations.
It doesn't specifically deal with reality. It certainly does not realistically model any workable process of speciation.

It deals with whatever it is that makes one individual different as far as ability to interbreed . It could be a mutation, it could be many mutations. It could be a trait, it could be many traits. Unlike you , I am not using a ‘black-box’ where the magician puts several interbreeding animals into a hat, waves a wand an pulls out speciated populations.

Unlike me, you are making the absolutely unjustifiable assumption that one single trait is an absolute bar to interbreeding, and any given organism either has that trait or doesn't have it. Worse, your model assumes that the descendants of any organism which has that trait have only a 50% chance of having it themselves. Speciation will never happen under those circumstances.

And as for "magic wands," where's the "magic" in assuming that descendants are not identical to their ancestors, Magellan?

Population genetics is based on evolutionary assumptions
It's based on no such thing. It's based on the empirical observation that differences are inherited. If you don't think differences are inherited, then you have to explain why dogs don't give birth to cats.

- hardly the way to investigate whether evolutionary processes actually work. But it looks like you will never grasp the the idea of begging the question.

Explain where the "evolutionary assumptions" are in my model, Magellan. You're great at making assertions. You're horrible in backing up those assertions.

My model makes two assumptions: 1) that mutations can be inherited, and 2) that mutations accumulate over time. If you think there are other assumptions, point them out with specificity, and/or explain why you think those two assumptions are not justified.

In my model the starting point is the first individual that cannot interbreed with Group A – not a percentage of the population.
There are undoubtedly individuals in my model which cannot interbreed with any member of the other group. In sylas's model there are explicitly members of one population which cannot interbreed with any members of the other group. So if you're trying to distinguish your unworkable model from our working model, you failed.

The sad thing for evolution is that my model shows you can’t ever get to a percentage of the population with that feature (inability to interbreed) unless you make assumptions that negate speciation.

Your "model" does no such thing. Your "model" assumes that any generation is as likely to revert to the genome of a previous generation as it is to become more different from the previous generation, an obvious stupidity given that there are nearly infinite ways for two genomes to be different but only one way for them to be the same.

Your "model" is irrelevant, Magellan. It doesn't matter whether or not speciation can happen under your "model." It clearly does happen under my model, so unless you can find something wrong or inconsistent with my model (something you have utterly failed to do so far), then you have no choice but to accept that my model works.

As long as a TYPE X can have ‘normal’ children, speciation won’t happen. I warned you about this.

Read my previous sentence, Magellan: your "model" is irrelevant, as long as there is some other plausible model under which speciation can and does happen. So stop talking about speciation not happening under your "model." It doesn't matter if it doesn't happen under your model. After all, you designed your model not to work.

In other words, my model shows that ‘fixation’ is a fantasy.

No. It shows that you designed your model so that fixation cannot happen. Your model has a built-in assumption (that even two X-Type parents can still have an N-type child, no matter how many generations ago the last X-type ancestor existed) that guarantees fixation cannot happen. Do you think it's remotely surprising that your bogus "model" prevents fixation?

And you will probably reply ‘Fixation does happen because without it you can’t have speciation.’

No. I'll reply that if your "model" explicitly prevents fixation, then speciation cannot happen, BY DESIGN.

There. I responded, as I typically do, to each and every sentence in your entire post. Meanwhile, you will continue to fail to respond to this post. (http://www.theologyweb.com/campus/showthread.php?144614-Evolution-of-The-Beetles&p=3204721#post3204721)

But if you don't want to respond to that post, Magellan, maybe you can just answer this question:

Why does speciation happen under sylas's simulation of my model?