From: Mark Walker (mark@permanentend.org)
Date: Sun Mar 16 2003 - 08:56:57 MST
Robert wrote:
> It is probably doubtful that evolution split the genomic differences
evenly
> between us and the chimpanzees. It could easily be 4%/1% or 1%/4%
depending
> on the selection pressures. I'd lean more in the direction that humans
ended
> up with more of the differences since it would seem that chimps are fairly
> well adapted to environments that existed 5 million years ago while humans
> have clearly gone through one or more population bottlenecks where we had
> to overcome some significant difficulties.
>
> > Is there solid evidence to suggest that our genome differs more from
> > our most recent common ancestor than chimps?
>
> No evidence that I'm aware of other than that I cite above. We may know
> a bit more once the chimp genome is done (we can see if there is perhaps
> less genome rearrangement). I believe that a collection of Asian
countries
> have started sequencing the chimp genome so we may know in a few years.
>
> Its going to be tricky however without the genome of one of those
ancestors.
> It might take doing a few other closely related primates to see if we can
> get back to the prototype primate genome and see if we have diverged more
> than some of the other primates.
>
Thanks. I agree that it seems likely that humans have gone through more
evolutionary bottlenecks, although there is still the question of how
pressures on phenotype relate to genome evolution--I'm thinking that to some
extent this will depend on whether Kimura's neutral theory of molecular
evolution is true, and to what extent. In general, though, I think people
tend to forget that whatever the percentage difference between us and chimps
is, it will probably be less than the difference between us and our most
recent common ape-like ancestors. (We can probably accept as unlikely
significant convergent evolution or horizontal transfer of genes). The
transhumanist cash-value of this question, in my mind, is that the smaller
the percentage difference between us and our most recent ape-like ancestor,
the more we can hope that relatively few genetic modifications may yield
quite big dividends.
Cheers,
Mark
Mark Walker, PhD
Research Associate, Philosophy, Trinity College
University of Toronto
Room 214 Gerald Larkin Building
15 Devonshire Place
Toronto
M5S 1H8
www.permanentend.org
This archive was generated by hypermail 2.1.5 : Sun Mar 16 2003 - 09:04:02 MST