In article <Pine.A32.3.91.960914002448.84578B-100000 at ux7.cso.uiuc.edu>,
biraju patel <b-patel4 at students.uiuc.edu> wrote:
>>1% of the population and approx 30% heterozygously. So since, most
>likely, it hasn't been long enough for that specific human population to
>"adapt" to HIV, why is the mutation or "HIV resistant" allele common in
>that population?
Since the general function of CCR5 (not 4, right?) is poorly understood,
and since collateral functions and side-effects of these receptors are
even more poorly understood, it seems to me that speculating on
evolutionary reasons for the mutation is at best premature. Assuming that
HIV has anything to do with it is even more premature. A simpler
explanation (which is, of course, completely unsupported by any evidence)
would be that the parasite(s) that the CCR5 system is most aimed at is
less abundant in the environment in which some populations developed, and
in the absence of this pressure null mutations are tolerated better.
Ian
--
Ian York (iayork at panix.com) <http://www.panix.com/~iayork/>
"-but as he was a York, I am rather inclined to suppose him a
very respectable Man." -Jane Austen, The History of England
