I thought this was generally accepted.
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Skulls confirm we're all out of Africa
By Ben HirschlerWed Jul 18, 1:21 PM ET
An analysis of thousands of skulls shows modern humans originated from a
single point in Africa and finally lays to rest the idea of multiple
origins, British scientists said on Wednesday.
Most researchers agree that mankind spread out of Africa starting about
50,000 years ago, quickly establishing Stone Age cultures throughout
Europe, Asia and Australia.
But a minority have argued, using skull data, that divergent populations
evolved independently in different areas.
The genetic evidence has always strongly supported the single origin
theory, and now results from a study of more than 6,000 skulls held
around the world in academic collections supports this case.
"We have combined our genetic data with new measurements of a large
sample of skulls to show definitively that modern humans originated from
a single area in Sub-Saharan Africa," said Andrea Manica of the
University of Cambridge's Department of Zoology.
Manica and colleagues wrote in the journal Nature that variations in
skull size and shape decreased the further a skull was away from Africa,
just like variations in DNA.
The decrease reflects the fact that, while the original African
population was stable and varied, only a small number of people embarked
on each stage of the multi-step migration out of Africa. This
effectively created a series of "bottlenecks," which reduced diversity.
The highest level of variation in skull types was seen in southeastern
Africa, the generally accepted cradle of mankind.
The Cambridge work also suggests in-breeding with other early humans,
such as Neanderthals, either did not happen or was insignificant. That
is in contrast to recent suggestions that such hybrids may have been
fairly common.
"We're not saying there was never a single mating between a homo sapiens
and a Neanderthal. But I can say, very confidently, that whatever the
product of that mating was, it didn't breed back into the population,"
Manica told Reuters.
Chris Stringer, a palaeoanthropologist at the Natural History Museum in
London, said the new research was important for indicating that modern
human diversity was derived entirely from Africa rather than coming from
inter-mixing elsewhere.
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http://tinyurl.com/29y9lg
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John #1782
"We should always be disposed to believe that which appears to us to be
white is really black, if the hierarchy of the church so decides."
- Saint Ignatius Loyola (1491-1556) Founder of the Jesuit Order.
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