[Taxacom] biased gene conversion
jgrehan at sciencebuff.org
Fri Feb 13 20:06:38 CST 2009
From: taxacom-bounces at mailman.nhm.ku.edu [mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Kenneth Kinman
Sent: Wednesday, February 11, 2009 3:36 PM
To: taxacom at mailman.nhm.ku.edu
Subject: [Taxacom] biased gene conversion
I find it a little hard to swallow that "many of the genetic changes
> leading to human-specific characters may be the result of the fixation of
> harmful mutations,"
Hard to swallow does not mean that it is not true. The part I don't understand is why many of the genetic changes have to represent harmful mutations.
> and that this contrasts with "the traditional Darwinistic view that they
> are the result of natural selection in favour of adaptive mutations."
It would seem to in that biased gene conversion would allow the spread of a mutant without requiring differential reproductive success.
> Although biased gene conversion could accelerate some evolutionary change
> (pushing more grist through the mill), natural selection (the mill itself)
> is still going to eventually act on that change.
Only if there is a change in fitness.
> Framing this as an either/or question just seems too simplistic.
I would agree in the sense that both processes may be involved in a co-evolutionary interaction (suggested by Gabriel Dover years ago).
> Natural selection keeps on "selecting" no matter how the genetic variation
> arises or what environmental changes occur. Frankly, I don't think Darwin
> would have any problem with biased gene conversion.
Dover wrote a whole book of imaginary correspondence between himself and Darwin on that very subject.
> However, I think he might take issue with the premature speculation on what
> biased gene conversion might be correlated with (such as homeothermy).
> And there are obviously forces which counteract biased gene conversion (and
> I believe that I read that many primate genomes have actually become less
> GC-rich compared to some other mammal groups).
No doubt, but until the process is explored rather than dismissed it will remain mysterious.
Taxacom Mailing List
Taxacom at mailman.nhm.ku.edu
The entire Taxacom Archive back to 1992 can be searched with either of these methods:
Or use a Google search specified as: site:mailman.nhm.ku.edu/pipermail/taxacom your search terms here
More information about the Taxacom