Received: by alpheratz.cpm.aca.mmu.ac.uk id BAA25874 (8.6.9/5.3[ref pg@gmsl.co.uk] for cpm.aca.mmu.ac.uk from fmb-majordomo@mmu.ac.uk); Fri, 8 Mar 2002 01:37:43 GMT Subject: Fwd: Study suggests love conquered all Date: Thu, 7 Mar 2002 20:32:24 -0500 x-sender: wsmith1@camail.harvard.edu x-mailer: Claris Emailer 2.0v3, Claritas Est Veritas From: "Wade T.Smith" <wade_smith@harvard.edu> To: "Memetics Discussion List" <memetics@mmu.ac.uk>, "SKEPTIC-L" <skeptic@listproc.hcf.jhu.edu> Content-Type: text/plain; charset="iso-8859-1" Content-transfer-encoding: quoted-printable Message-Id: <20020308013222.3EB671FD4D@camail.harvard.edu> Sender: fmb-majordomo@mmu.ac.uk Precedence: bulk Reply-To: memetics@mmu.ac.uk
Study suggests love conquered all
Early man's evolution a process of mingling, not conquest, researcher
says
Robert Lee Hotz, Los Angeles Times
Thursday, March 7, 2002
©2002 San Francisco Chronicle
URL:
http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2002/03/07/MN227595.DTL
Spreading out of Africa like starlings, early humans conquered the world
by embracing the strangers they encountered around the globe, not by
forcing them into extinction, as many researchers believed, according to
a new analysis of human genetic history.
In the textbook view, the founding fathers of modern humanity emerged
suddenly from Africa about 100,000 years ago and swept into oblivion all
other prehuman species -- Neanderthals, for example -- that they
encountered.
A new and elaborate computer genealogy of 11 inherited traits compiled by
Alan Templeton at Washington University in St. Louis presents a very
different slant on the origins of diversity.
Templeton's work, published today in the journal Nature, suggests that
"interbreeding, not replacement," was the rule for successive waves of
primitive humans migrating out of Africa. By mingling, these ancestral
human groups "strengthened the genetic ties between human populations
throughout the world," said Templeton, who studies the history and
geography of genes.
In his view, the ancient world was a vast melting pot in which tribes of
human ancestors scattered, rejoined and scattered again. As they did so,
they gradually intermingled inherited traits across thousands of
generations to mix the palette of modern humanity.
Templeton's work is the latest riposte in a 20-year-long debate in which
anthropologists, archaeologists, molecular biologists and population
geneticists have battled over human origins with rounds of research
papers scattered like hand grenades.
For all their differences, both camps agree that the earliest ancestors
of humankind evolved in Africa about 2 million years ago, before
beginning waves of migration into Europe and Asia.
Where the scientists part company is in deciding how those ancestral
groups gave rise to anatomically modern people -- with their small
pointed jaws, smooth foreheads, high rounded skulls and advanced mental
abilities.
Frustrated by the ambiguous fossil record, researchers have turned to the
genes that code for growth and development to flesh out this missing
chapter of human evolutionary history.
To reach his conclusions, Templeton combined published data on 11 parts
of the human genome. He analyzed mitochondrial DNA -- genetic material
that each person inherits directly from his or her mother -- as well as
data from genes carried on the Y chromosome, which is inherited only from
fathers. He also looked at genes on other chromosomes that can be
inherited from either parent.
His computer analysis detected considerable gene mixing and evidence of
two separate waves of migration out of Africa into Asia and Europe -- the
first between 420,000 and 840,000 years ago and a more recent one between
80,000 and 150,000 years ago.
Other researchers agree that there was generous mixing of valuable
genetic traits. But they disagree about when it might have happened.
"If those ancestral populations were all in different valleys in Africa,
you would see the same thing," said Henry Harpending, a University of
Utah anthropologist. "This may have been gene flow between ancestral
populations in Kenya, Uganda and Tanzania."
Templeton made a "valiant effort," but his study "all seems too iffy to
me, " Harpending said. "Going from his findings to this sweeping picture
of human evolution is a jump I can't see."
But University of Michigan paleoanthropologist Milford Wolpoff said he
felt vindicated by Templeton's work. Wolpoff has long championed the idea
that modern humans evolved more or less simultaneously around the globe
by sharing their best characteristics.
Templeton's analysis "shows that human evolution is about traits and not
about kinds of people," Wolpoff said. "Lots of things separate human
populations, but more things unite them."
©2002 San Francisco Chronicle Page A - 2
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