Re: The History and Geography of Human Genes (Was: "Mainstream

Fury (fury@dartmouth.edu)
19 Jan 1995 04:49:20 GMT

In article <tlathropD2MqBn.2qn@netcom.com>
tlathrop@netcom.com (Tom Lathrop) writes:

> So how long would it take for a relatively minor difference such as
> this to arise between two populations? I don't know for sure, but it
> seems to me that any period of time measured in tens of thousands of
> years would be plenty. If you disagree, then you need to give me some
> estimate of how long *you* think it would take, and support it.
> Otherwise you are simply not justified in claiming that the new genetic
> studies show that there hasn't been enough time for such a difference
> to arise.

When I saw the list of crossposted groups on this one, I was frankly
amazed! (I've cut this down to sci.anthropology, since that's where I
found it.) Is this a blatant troll or a serious discussion (I've just
come in on this one... I haven't kept up with news in years.)? And
does the above quoted poster read sci.anthropology?

Assuming this is actually something other than a blatant troll: I am
kind of sleepy with the flu but reading this paragraph my basic
biological anthropology class comes flooding back to me: why would a
trait like intelligence be adaptive for only small portions of the
population? I can understand why an trait such as skin color or height
or presence of the sickle cell allele would change relatively quickly
and stay different in a small population if it were only adaptive for
certain environments, but presumably higher intelligence is adaptive
for everyone. Since it has been established (see epicanthic fold
discussion) that there is a continuum of intermarriage around the world
and yet some traits remain localized because they are only locally
useful, why would increased intelligence not spread rampantly?

I'm still hoping this is really a troll, but it's late and I have the
flu so...

Jane
fury@dartmouth.edu