New Information?

[wattsr1]

Hi All,


In a recent piece of research (1), scientists were able to demonstrate that ordinary baker’s yeast Saccharomyces cerevisiae, arose via a whole genome duplication from an ancestor somewhat like Kluyveromyces waltii. They saw interleaved clusters of genes forming a 2:1 ratio. They could find direct comparisons between genes of the two species. Gene order between the two species was maintained. Thus the authors of the article wrote:-

The clearest way to prove the existence of an ancient WGD would be to find a yeast species, denoted as Y, that descends directly from a common ancestor along a lineage that diverged before the duplication. In principle, species Y and S. cerevisiae would be related by a 1:2 mapping satisfying several properties:-

(1) Nearly every region in species Y would correspond to two sister regions in S. cerevisiae;

(2) The two sister regions in S. cerevisiae would each contain an ordered subsequence of the genes in the corresponding region of species Y, with each containing roughly half of the genes and the two subsequences interleaving to account for nearly all of the genes; and

(3) Nearly every region of S. cerevisiae would correspond to one region in species Y, and thus be paired to a sister region in S. cerevisiae.

And this is what they saw when they compared S. cerevisiae with Kluyveromyces waltii, the latter being species Y in the above quote.

Following the WGD, the evidence is that most genes were simply and quickly removed from the genome of S. cerevisiae as it tried to stabilize. Roughly 10% of the duplicated genes did survive however and of these, some of either pair did so by taking on new functions that did not exist in the ancestral species. Many others of either pair did so by evolving new functions from ancestral but differing functions.

My question is:-

Leaving aside the tricky question of a definition of information, how can anyone argue that this is not a gain? A species now exists that did not exist before and it has somewhat more DNA than the critter it came from, with that DNA coding for functions that did not exist in the ancestor.


Comments anyone?



Regards, Roland


Reference:

(1) Manolis Kellis, Bruce W. Birren & Eric S. Lander, “Proof and evolutionary analysis of ancient genome duplication in the yeast Saccharomyces cerevisiae”, Nature 428 8-April-2004, pages 617-624.

[FreezBee]

And this is what they saw when they compared S. cerevisiae with Kluyveromyces waltii, the latter being species Y in the above quote.

Following the WGD, the evidence is that most genes were simply and quickly removed from the genome of S. cerevisiae as it tried to stabilize. Roughly 10% of the duplicated genes did survive however and of these, some of either pair did so by taking on new functions that did not exist in the ancestral species. Many others of either pair did so by evolving new functions from ancestral but differing functions.

My question is:-

Leaving aside the tricky question of a definition of information, how can anyone argue that this is not a gain? A species now exists that did not exist before and it has somewhat more DNA than the critter it came from, with that DNA coding for functions that did not exist in the ancestor.

Really good, Roland

Let's see how good ol' Jorge will counter this one.


- FreezBee

[wattsr1]

Really good, Roland

Let's see how good ol' Jorge will counter this one.


- FreezBee

Thanks FB.

Well even though Jorge has been quite active, he has ignored it so far. That is one method of Jorge for "countering" things.

Now that this little dig is posted he will probably chip in with an insult.

Beyond these, he will do nothing. Frankly I doubt if he understands what is being argued and why.


Regards, Roland