New Out-Of-Africa Theory Unveiled

Everyone outside of Africa — Asians, Europeans, Native Americans, Southeast Asians, Australian Aborigines, etc. — came from the same small band of humans that left the mother continent some 80,000 years ago by way of Ethiopia, according to a new theory unveiled Monday by geneticists and DNA detectives.

"No, we haven't found the bones of the original Eve," said DNA tracker Stephen Oppenheimer of Oxford University in a press teleconference.

Instead, researchers have followed the trail of mitochondrial DNA, which we inherit unchanged from our mothers, and backtracked down the branching tree of the human family throughout the world.

If the mitochondrial DNA story is correct, then we all descend from a woman who lived in Africa 150,000 years ago, said geneticist Martin Richards of Huddersfield University in England, who also took part in the briefing.

Oppenheimer and Huddersfield will appear in "The Real Eve," a Discovery Channel documentary premiering on April 21.

What's more, all non-Africans come from a small group of people who ventured out of Africa some 80,000 years ago, perhaps because of climate changes along the Red Sea shore that made life there too difficult, he said.(maybe it dried up during the Ice Age, huh?)

Genetic evidence of that small band can be found today in India, said Oppenheimer. "In India, all of the early lines that gave rise to Asians and Europeans are found in great profusion and great antiquity," he said.

For years anthropologists have debated whether humans left Africa by a northern route — via the present-day Suez Canal region — or by a southern route, via a short-lived isthmus connecting Ethiopia to Yemen at the southern end of the Red Sea. Some researchers have even suggested that Europeans descend from the people of the northern exodus and the rest of non-Africans from the people of the southern exodus.

"The fact that we look different is because we live in different environments," said Oppenheimer. "(But) we are really, truly the same under the skin."

The single exodus theory also meshes well with other genetic and archeological discoveries. Last year, researchers working on the Human Genome Project reported that the pool of human genetic material is startlingly small, implying we are a young species and come from a very small group of Africans.

However, not everyone is convinced of the single group theory, said paleontologist Tim White of the University of California at Berkeley. "My sense in it is that we're not close to the bottom line yet," he told Discovery News.

Genetics has yielded some new data to the mix, he said, but the smoke hasn't yet cleared enough to see the details of exactly when and where modern humans came out of Africa.

The Japan Times
January 29, 2001
By MAGGIE FOX

African Eve or multiregional origins? Maybe both

WASHINGTON (Reuters) The out-of-Africa theory is not dead, anthropologists and other experts say this week, despite two recent studies that challenge the idea we are all descended from a single African "Eve."

U.S. and Australian researchers published two reports that used physical and genetic evidence to suggest there may have been mixing of pre-humans with modern species.

They said they had proved wrong the mainstream out-of-Africa theory that the ancestors of all living humans emerged from Africa some 50,000 years ago and either killed off or out-competed all other humanlike creatures who settled across much of the world.

One study used genetic evidence that suggested "Mungo Man," an Australian skeleton dated to between 40,000 and 60,000 years ago, is genetically unrelated to Africans. The researchers, Gregory Adcock of Australian National University and colleagues, said their finding showed the first modern humans evolved in Australia, not Africa.

Another, published in Friday's issue of the journal Science, analyzed physical features of early human skulls to suggest there must have been interbreeding among the migrating Africans and resident Neanderthals and even Homo erectus species of prehumans.

"There never was a marauding band of Africans," University of Michigan anthropologist Milford Wolpoff, who led the second study, said in a telephone interview.

"It certainly means that the "Eve" theory, the replacement theory, seems to be wrong."

The Australian team and Wolpoff and colleagues belong to the "multiregionalist" school of human evolution. They believe humans evolved around the world at roughly the same time, and that they probably mixed with earlier species such as Neanderthals and Homo erectus.

The out-of-Africa school says that all earlier humans died out and were replaced by a small group from Africa who quickly conquered the world.

Some experts say the two theories are not incompatible, although they predict a fight over the latest studies.

"There might be a lot of finger-pointing and name calling and debate that is more heat than light," says Peter Underhill of Stanford University, who has published genetic studies that date our common ancestors to an African man who lived 59,000 years ago and an African woman who lived 143,000 years ago.

"But I don't think it torpedoes the recent out-of-Africa scenario at all. I don't think these two papers are going to turn the world of human evolution on its head."

It does not matter whether early humans mixed or evolved into "modern" forms in more than one place, Underhill says. The out-of-Africa theory holds only that one lineage finally held sway, either through luck, better genes, or a combination of the two.

We are all descended from that lineage, he says. "Everyone on Earth today is very closely related," he says.

"It might suggest that there was some hybridization with moderns and possibly other modern lineages that existed 60,000 years ago that are now extinct, or it is possible there was some kind of hybridization with some sort of archaic human that lived in the past," Underhill adds.

"But no one is walking around so far in Europe with Neanderthal genes."(I believe this is false)

So if both theories can coexist, why argue?

"Egos, egos egos," Underhill says. "Scientists are human."

Clark Howell, a professor emeritus of human evolution at the University of California Berkeley, agrees.

"There is a tendency in some instances for some people at some times to jump to very wide, sweeping conclusions," he says. "In my view these two studies don't upset any applecarts."

In other words, modern humans may have indeed evolved in places other than Africa. They may even have mated occasionally with Neanderthals, who did live at the same time and in the same places. But genetically, they have since died out.

"If we are looking for the ancestry of modern people, where people alive today came from, where their genes came from — if there was such hybridization it is negligible. It is impossible to find today," says Chris Stringer, head of human origins at London's Natural History Museum and an architect of the out-of-Africa theory.

Body links Neanderthal to modern man

Written by Janel Bladow.

NEW YORK, April 19 (UPI) - The centuries-old body of a 4-year old child found buried in central Portugal is creating a sensation in scientific circles as it links the Neanderthal to modern man. The child's remains show characteristics of both, which until now, many thought did not interbreed. "This find tells us about what it means to be human," Erik Trinkaus, professor of anthropology, arts and sciences at Washington University in St. Louis, told UPI in an interview today. Trinkaus is working directly with Joao Zilhao, Portugal's director of antiquities who is overseeing the excavation team.

"This skeleton, which has some characteristics of Neanderthals and others of early modern humans, demonstrates that early modern humans and Neanderthals are not all that different. They intermixed, interbred and produced offspring," he said. "Many people like to distance themselves from Neanderthals," said Trinkaus. "The significance of this discovery is that many believe when modern men spread across Europe, they displaced those who were already there. They believe the Neanderthal died out without issue. This refutes that argument."

The child is believed to be a 4-year-old boy who lived 24,500 years ago. He has a chin, a clear characteristic of early modern humans; Neanderthals did not have chins. But he also has a stocky body and short limbs, the body proportions of Neanderthals. Modern men had liner bodies and long limbs. The skeleton was found in the Lapedo Valley north of Lisbon in Portugal, buried on a hillside with a pierced shell and red ochre, which indicates a ritual burial. Radio-carbon dating confirms that the skeleton is 24,500 years old, 4,000 years after the time that Neanderthals and early modern humans co-existed on the Iberian Peninsula.

"This is pretty exciting," said Trinkaus. "It is the first paleontologic burial discovered in Iberia. It is a ritual burial. We can tell that because the body was covered with red earth, called red ochre. And it was buried with a pierced shell by its neck. This places its time period around 20,000-30,000 range. "In ritual burials at that time, bodies were covered with varying amounts of ochre on them, an obvious analogy to blood. Almost all of these burial included a pierced shell or animal teeth, that of a fox or bear. Beyond this we don't know the significance of the ochre or the shell or teeth. "What is clear though, is that this is the burial of a 4-year-old child and that either everyone had these types of burials or this individual had some status from its parents."

Since the Nov. 28 discovery of the burial site and Dec. 5 when scientists stumbled on the child's body - a Portuguese biologist reached into a rabbit hole and pulled out a limb - only a small portion of the skeleton has been pieced together. Another significant aspect of the discovery is that the child lived about 4,000 years after early modern humans moved into the Iberian Peninsula. This means that the two populations lived there together for a few thousand years. "This was not a chance mating, this is a case of population intermixing," said Trinkaus. "The other thing this says is that whatever these people look like to us, back then, they were all were just humans. Hunters and gathers all living on land and meeting up to become one population which then evolved and became various groups.

"The broader issue here is that some people want to make the Neanderthal different from us. They want modern humans to be special. But the modern man isn't all that special in the greater scheme of things," says Trinkaus. Also significant in the discovery is that the child was found on the Iberian Peninsula only 24,500 years ago, said Fred Smith, professor of anthropology at Northern Illinois University in DeKalb. "This shows the exchange between Neanderthal and modern man to be more recent in time." He told UPI. "I thought it would be 30,000 years ago. The big debate has been if the Neanderthal contributed to gene pool in Europe. This suggests that there was some assimilation of the Neanderthal into the early modern gene pool."

The skeleton is being pieced together at the National Archeology Museum in Lisbon by an international team. They will be studying the health of the child, called Lagar Velho 1 (old wine press after the name of site), aspects of its growth, and other genetic information. Scientists plan to return to the site in July. The area was first bulldozed by builders six years ago and the child's grave was missed by 2 inches. At Christmas some 2,000 people came to see where the child was found. Older village women admonished the scientists to "take good care of our boy," says Trinkaus.

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