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Last edited by Zymologist; 06-15-2018, 09:05 AM.Geislerminian Antinomian Kenotic Charispneumaticostal Gender Mutualist-Egalitarian.
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Originally posted by NorrinRadd View PostI'm politely asking questions with NO agenda • Edited by a Moderator •
I'm always still in trouble again
"You're by far the worst poster on TWeb" and "TWeb's biggest liar" --starlight (the guy who says Stalin was a right-winger)
"Overall I would rate the withdrawal from Afghanistan as by far the best thing Biden's done" --Starlight
"Of course, human life begins at fertilization that’s not the argument." --Tassman
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Originally posted by NorrinRadd View PostI'm politely asking questions with NO agenda • Edited by a Moderator •
For example: If you make an assertion concerning dinosaur DNA found simply provide a scientific reference concerning this.Last edited by shunyadragon; 06-16-2018, 06:16 AM.Glendower: I can call spirits from the vasty deep.
Hotspur: Why, so can I, or so can any man;
But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:
go with the flow the river knows . . .
Frank
I do not know, therefore everything is in pencil.
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Originally posted by rogue06 View PostNo DNA found. If someone is claiming otherwise they are deliberately misrepresenting things. At that point you should ask why do they find it necessary to rely on falsehoods to support their claim.
First, I should note that Mary Schweitzer[1], the paleontologist at North Carolina State University who first discovered so-called "soft tissue," inside the femur of a T rex, did at one time say that they did find DNA on the fossil, BUT she was very careful to not say it was dinosaur DNA ("Whoever it belongs to is a mystery"). It is likely extraneous DNA derived from bacteria or even humans from handling the sample. It is incredibly easy to contaminate a sample even under the best of conditions[2] and considering that they were not originally thinking about looking for DNA they weren't taking precautions.
Second, what often gets glossed over is that these soft tissies aren't exactly soft. They had to soak the material in an acidic solution over a period of several days in order to get it even slightly pliable.
Third, it looks like Schweitzer and her colleagues have discovered a mechanism that may account for how the "soft tissue" was preserved for so long a period of time back in 2013.
The entire paper is available at the link above.
The take-away here is that iron nanoparticles associated with dinosaur blood vessels were identified (the researchers think that they originated from the blood and muscle cells during decay) and moreover were able to identify iron-facilitated reactions that contribute to preservation. IOW, iron may indeed play an important role in preserving ancient tissues within dinosaur fossils before it can decay.
As Schweitzer explained:
Iron is necessary for survival, but it's also highly reactive and destructive in living tissues, which is why our bodies have proteins that transport iron molecules to where they are needed but protect us from unwanted reactions at the same time. When we die, that protective mechanism breaks down and the iron is turned loose on our tissues -- and that destructive process can act in much the same way formaldehyde does to preserve the tissues and proteins.
Because both birds and crocodiles -- the closest living relatives of the dinosaurs -- have large, nucleated red blood cells with more hemoglobin per cell than mammals, meaning that it is highly likely that dinosaur's red blood cells also contained much more hemoglobin, which would therefore act to amplify its preserving effect on tissue.
Also, if the hemoglobin were contained in a bone in an arid sandy environment (as indicated by the type of sandstone it was encased in), keeping it dry and insulated from microbes, preservation becomes even more likely.
Moreover, proposing a naturally occurring mechanism for the stabilization of soft tissues may very well have important connotations outside of paleontology. As researchers at the Lawrence Berkeley National Laboratory in California have pointed out
"If iron-mediated reactions are part of a continuum from those that facilitate life processes (e.g. cellular respiration, oxygen transport) to fully mineralized, it may be possible to propose a molecular pathway for reactions causing diseases in humans, and once such a pathway is identified, it may be possible to propose ways to interrupt this process."
Finally, a couple years after this (2015) another possible way that it could have been preserved for such a long time was proposed
I guess the point of all this is that scientists are constantly finding things that they didn't expect to find, but any scientist worth his salt is going to investigate it rather than throw everything they do know and retreat into some cave. The fossils were found embedded in sediments that have been repeatedly dated through several different means to the Mesozoic so it was reasonable to continue with that as a starting point rather than allowing wild speculations to take hold. Searching for a mechanism to explain preservation of these materials over much longer than expected period of time was the logical thing to do and appears to have been successful.
1. In an interview of Schweitzer, who is an evangelical who describes herself as "a complete and total Christian," stated that she has begun to take it personally when evolution deniers misrepresent her work saying that, “They twist your words and they manipulate your data.” She would reiterate this roughly eight years later during an interview for BioLogos (a Christian advocacy group established by Francis Collins)
One thing that does bother me, though, is that young earth creationists take my research and use it for their own message, and I think they are misleading people about it. Pastors and evangelists, who are in a position of leadership, are doubly responsible for checking facts and getting things right, but they have misquoted me and misrepresented the data. They’re looking at this research in terms of a false dichotomy [science versus faith] and that doesn’t do anybody any favors
2. A couple years ago I read Phillip Manning's Grave Secrets of Dinosaurs: Soft Tissues and Hard Science which is largely about fossilized dinosaur mummies, especially "Dakota" an Edmontosaurus, which had a good bit of skin and muscle fossilize and which Manning helped to excavate. Manning mentions several times how easy it is to contaminate fossils with modern DNA even through things like the plaster that is used to wrap the rocks the fossils are found in for transportation.
Prior to this I remember their was a great deal of interest in the discovery of some human DNA in some dried out wolf dung in a cave in the American Northwest that significantly pre-dated the Clovis culture. One of the concerns raised was whether the lab had adequately cleaned their testing equipment which could have contaminated the sample with modern human DNA.Last edited by rogue06; 06-26-2018, 03:45 PM.
I'm always still in trouble again
"You're by far the worst poster on TWeb" and "TWeb's biggest liar" --starlight (the guy who says Stalin was a right-winger)
"Overall I would rate the withdrawal from Afghanistan as by far the best thing Biden's done" --Starlight
"Of course, human life begins at fertilization that’s not the argument." --Tassman
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Originally posted by rogue06 View PostElaborating a bit about "soft tissues"
First, I should note that Mary Schweitzer[1], the paleontologist at North Carolina State University who first discovered so-called "soft tissue," inside the femur of a T rex, did at one time say that they did find DNA on the fossil, BUT she was very careful to not say it was dinosaur DNA ("Whoever it belongs to is a mystery"). It is likely extraneous DNA derived from bacteria or even humans from handling the sample. It is incredibly easy to contaminate a sample even under the best of conditions[2] and considering that they were not originally thinking about looking for DNA they weren't taking precautions.
Second, what often gets glossed over is that these soft tissies aren't exactly soft. They had to soak the material in an acidic solution over a period of several days in order to get it even slightly pliable.
Third, it looks like Schweitzer and her colleagues have discovered a mechanism that may account for how the "soft tissue" was preserved for so long a period of time back in 2013.
The entire paper is available at the link above.
The take-away here is that iron nanoparticles associated with dinosaur blood vessels were identified (the researchers think that they originated from the blood and muscle cells during decay) and moreover were able to identify iron-facilitated reactions that contribute to preservation. IOW, iron may indeed play an important role in preserving ancient tissues within dinosaur fossils before it can decay.
As Schweitzer explained:
Iron is necessary for survival, but it's also highly reactive and destructive in living tissues, which is why our bodies have proteins that transport iron molecules to where they are needed but protect us from unwanted reactions at the same time. When we die, that protective mechanism breaks down and the iron is turned loose on our tissues -- and that destructive process can act in much the same way formaldehyde does to preserve the tissues and proteins.
Because both birds and crocodiles -- the closest living relatives of the dinosaurs -- have large, nucleated red blood cells with more hemoglobin per cell than mammals, meaning that it is highly likely that dinosaur's red blood cells also contained much more hemoglobin, which would therefore act to amplify its preserving effect on tissue.
Also, if the hemoglobin were contained in a bone in an arid sandy environment (as indicated by the type of sandstone it was encased in), keeping it dry and insulated from microbes, preservation becomes even more likely.
Moreover, proposing a naturally occurring mechanism for the stabilization of soft tissues may very well have important connotations outside of paleontology. As researchers at the Lawrence Berkeley National Laboratory in California have pointed out
"If iron-mediated reactions are part of a continuum from those that facilitate life processes (e.g. cellular respiration, oxygen transport) to fully mineralized, it may be possible to propose a molecular pathway for reactions causing diseases in humans, and once such a pathway is identified, it may be possible to propose ways to interrupt this process."
Finally, a couple years after this (2015) another possible way that it could have been preserved for such a long time was proposed
I guess the point of all this is that scientists are constantly finding things that they didn't expect to find, but any scientist worth his salt is going to investigate it rather than throw everything they do know and retreat into some cave. The fossils were found embedded in sediments that have been repeatedly dated through several different means to the Mesozoic so it was reasonable to continue with that as a starting point rather than allowing wild speculations to take hold. Searching for a mechanism to explain preservation of these materials over much longer than expected period of time was the logical thing to do and appears to have been successful.
1. In an interview of Schweitzer, who is an evangelical who describes herself as "a complete and total Christian," stated that she has begun to take it personally when evolution deniers misrepresent her work saying that, “They twist your words and they manipulate your data.” She would reiterate this roughly eight years later during an interview for BioLogos (a Christian advocacy group established by Francis Collins)
One thing that does bother me, though, is that young earth creationists take my research and use it for their own message, and I think they are misleading people about it. Pastors and evangelists, who are in a position of leadership, are doubly responsible for checking facts and getting things right, but they have misquoted me and misrepresented the data. They’re looking at this research in terms of a false dichotomy [science versus faith] and that doesn’t do anybody any favors
2. A couple years ago I read Phillip Manning's Grave Secrets of Dinosaurs: Soft Tissues and Hard Science which is largely about fossilized dinosaur mummies, especially "Dakota" an Edmontosaurus, which had a good bit of skin and muscle fossilize and which Manning helped to excavate. Manning mentions several times how easy it is to contaminate fossils with modern DNA even through things like the plaster that is used to wrap the rocks the fossils are found in for transportation.
Prior to this I remember their was a great deal of interest in the discovery of some human DNA in some dried out wolf dung in a cave in the American Northwest that significantly pre-dated the Clovis culture. One of the concerns raised was whether the lab had adequately cleaned their testing equipment which could have contaminated the sample with modern human DNA.Glendower: I can call spirits from the vasty deep.
Hotspur: Why, so can I, or so can any man;
But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:
go with the flow the river knows . . .
Frank
I do not know, therefore everything is in pencil.
Comment
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