From: Glenn Morton (glenn.morton@btinternet.com)
Date: Thu Jan 02 2003 - 15:51:59 EST
I have been reading a bunch of anthro books over the holidays and ran across
a couple of very interesting facts which have an impact on whether or not
mitochondrial Eve can tell us anything about human ancestry. For those who
might not know, mitochondrial Eve (mtDNA Eve) is the lady who was lucky
enough to have left her mitochondrial DNA in all modern humans. She is
believed to have lived between 100 and 200 kyr ago. Her mitochodria in all
of us has been taken as proof that there was no interbreeding between the
peoples who came out of Africa aproximately 150,000 years ago and the
previous old world populations, i.e., Neanderthals and H. erectus. This out
of Africa view holds that there was a total replacement of the ancient
hominids by the moderns.
Many Christians have attached themselves to this theory, claiming that Eve
is equal to Biblical Eve. While there are lots of reasons this can't be the
case, the thrust of this note is that the logic these conclusions is
falsified by observational evidence.
We will start with chimpanzees. Chimpanzee females, when they become
sexually mature have a high chance of leaving the home group. Pusey writes:
"During my study, one female from the Kasekela and one from the Kahama
community reached adolescence. Each, after mating within the natal
community, visited the other community while sexually receptive. While both
were fearful of and reluctant to mate with some of the males in their own
community, they eagerly approached and mated with males from the new
community, and these males also appeared to find them more attractive than
their own females. While the Kahama female eventually joined the Kasekela
community permanently, the Kasekela female returned, pregnant, after six
months. Since then, almost all females have made similar visits to other
communities during adolescence, and over half of them have left their home
community permanently. Over the same period many new females have joined
the community and settled thee at adolescence; others have visited for
various periods, often in the face of considerable aggression from resident
females. At Mahale, Tai and Kibale an even higher proportion of females
(about 90 percent or more) have emigrated permanently during adolescence."
Anne E. Pusey, ìOf Genes and Apes: Chimpanzee Social Organization and
Reproduction,î in Frans B. M. de Waal, editor, Tree of Origin: What Primate
Behavior Can Tell Us About Human Social Evolution, Cambridge, MA: Harvard
University Press, 2001), p. 20
This behavior is called patrilocal because the men stay put and the women
migrate. What is the effect of this pattern of behavior over time? In
chimpanzees we find:
ìSome individuals at Gombe shared mitochondrial genes with individuals
several hundred kilometers awayóevidence for extensive successful migration
by females in the recent past.î Anne E. Pusey, ìOf Genes and Apes:
Chimpanzee Social Organization and Reproduction,î in Frans B. M. de Waal,
editor, Tree of Origin: What Primate Behavior Can Tell Us About Human Social
Evolution, Cambridge, MA: Harvard University Press, 2001), p. 22
In other words, this type of behavior has the effect of spreading the female
mitochondrial all over the place. And eventually, as with humans, one female
chimp will be the progenitor of all chimp mitochondria although chimps have
about 8 times the diversity of mtDNA as humans. Unlike humans, chimps can't
cross major rivers. (see William C. McGrew, ìThe Nature of Culture:
Prospects and Pitfalls of Cultural Primatology,î in Frans B. M. de Waal,
editor, Tree of Origin: What Primate Behavior Can Tell Us About Human Social
Evolution, Cambridge, MA: Harvard University Press, 2001), p. 248)
Now when we turn to mankind we find that ancient hunter-gatherers were
patrilocal also. Luis Arsuaga notes:
ìWhat is more, the majority of hunter-gatherer groups on record were or are
patrilocal, meaning that sons stay in their birth groups while daughters
leave theirs. Based on this evidence, many researchers believe it more
likely that prehistoric hominids were also patrilocal, although Hawkes and
her colleagues disagree.î Juan Luis Arsuaga, The Neanderthalís Necklace,
transl. By Andy Klatt, (New York: Four Walls Eight Windows, 2002), p. 164
The effect of this is that if Human/Neanderthal interbreeding took place,
and Neanderthals were few in number, that human females could have spread
their mtDNA and eventually replaced the Neanderthal mtDNA. And if this
happened, then the Neanderthal's whose mtDNA has been tested and found to be
different from ours may have a different explaination. The three Neanderthal
mtDNA's come from the Feldhofer Neanderthal(~40,000 years old), Mezmaiskaya
(>45,000 years old) and Vindija (G3 level 42,400 years old). Note that the
ages of all these Neanderthals, whose different mtDNA is taken as proof that
there was no interbreeding between them and the moderns, are from a time
period BEFORE modern humans even are believed to have entered Europe. Thus
the fact that their mtDNA was different is only due to the fact that they
were an isolated community prior to the anatomically modern human invasion.
Their early dates preclude them from providing any information concerning
any possible interbreeding.
As I have posted earlier on this list, there is ample evidence for this
crossbreeding and the evidence used against it is totally and logically
irrelevant to that question.
References
L. V. Golovanova, et al, "Mezmaiskaya Cave: A Neanderthal Occupation in the
Northern Caucasus," Current Anthropology, 40(1999):1:77-86,
glenn
see http://www.glenn.morton.btinternet.co.uk/dmd.htm
for lots of creation/evolution information
anthropology/geology/paleontology/theology\
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