Re: local evolutions
Yousuf Khan (ykhan@achilles.net)
Sat, 24 Aug 1996 14:29:56 GMT
On Thu, 22 Aug 1996 09:35:48 -0500, "C. Marc Wagner @ UCS"
<mwagner@indiana.edu> wrote:
>Yousuf Khan wrote:
>>
>> Hello, I'm an interested amateur. I am interested in a theory
>> espoused by some anthropologists whose names eludes me right now.
>> They are the ones who believe that homo sapiens evolved out of
>> all of the regionalized pockets of homo erectuses already in
>> existence throughout the world at that time.
>I think that this theory has begun to fall out of favor in recent years
>as genetic evidence has come down on the side of the "Out of Africa"
>theory that several times in the past Hominids have migrated out of
>Africa. If I understand it correctly, the genetic evidence suggests
>that all living Homo sapiens sapiens are descended from a single female
>who lived around 800KYA. Much later than Homo erectus left Africa.
However, what evidence is there that it did originate in Africa?
All we can guess at is how long ago it happened, but that doesn't
tell us where it happened: it could've happened in Africa, but
not necessarily so.
Anyways, I believe that erectuses were just a different breed of
sapiens, and perhaps with the flow of genetic material, gradually
over time, the one genes that gave us our larger brains became
the fashionable trend among humans (much like blonde hair seems
to be desired by many now), and the gene got passed back and
forth over the human populations until our brains were much
bigger. And it still doesn't preclude an origin of that
particular gene about 800KY ago (as you said), it just
establishes a timeline for when it began to happen.
>Other studies suggest that genetic diversity among Africans is much
>greater than among non-Africans, also supporting a "recent" migration
>"Out of Africa."
What exactly do you mean? How do you measure genetic diversity?
>Personally, I doubt that a "parallel evolution" of Homo erectus,
>happening simultaneously all over the World could have resulted in a
>single species rather then a number of variant species incapable of
>interbreeding. There just doesn't seen to be enough opportunity for
>mixing of stock to avoid divergent evolution of such groups.
You're taking it much too literally. We have regionalized pockets
of human breeds all over the world: negros, orientals,
caucasians, polynesians, etc. They all share certain similarities
in appearance. Where you get cross-overs of territory, you also
get cross-overs of racial features; and with today's modern
world, the cross-over territories are even larger. Now if all of
the pools of peoples throughout the world were linked by these
cross-over territories, new features would be naturally flowing
back and forth between all of the people, yet certain
regionalized features would continue to be favoured.
>> Also, would like some sites devoted to the aquatic ape theory,
>> both pro and con (if possible). Sounds fascinating.
>The AAT (Aquatic Ape Theory) has been FLAMED a great deal in this
>newsgroup over the last few months. I get the sense that few in the
>field put much credence in it. I am sorry that I cannot direct you to
>more information.
Quite, but I'm of the opinion that even if their conclusions
about a great migration towards the sea is not true, they may
have still stumbled upon some evidence that increased our
versatility as hunters. These features may not have led us to the
sea, but they may have let us go fishing, for example. :-)
Yousuf Khan
--
Yousuf J. Khan
ykhan@achilles.net
Ottawa, Ont, Canada
Nation's capital
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