A Kansas University scientist studied very old bones and found something wrong with the Eve theory.
KU anthropology professor David Frayer was part of a team that analyzed ancient skulls from around the world and found evidence that modern humans did not arise from a single migration from Africa.
Instead, there were small groups that journeyed to every continent, intermingling with archaic humans such as the Neanderthal.
The team's research on human origins was published in today's issue of the journal Science.
Frayer and fellow team members from the universities of Michigan and Utah examined and compared ancient skulls from different periods from central Europe, Australia and Africa.
Their findings contradict the Eve theory, which holds that modern humans evolved in Africa and moved into the rest of the world in a singular movement of perhaps 10,000 people. Once on the other continents, the theory holds, the moderns supplanted the existing more ancient humans, such as the Neanderthal.
But Frayer and his co-authors said that skulls dated 25,000 to 30,000 years from Europe and from Australia share strong characteristics of 40,000 to 200,000-year-old archaic human skulls found in Europe, Indonesia, and Africa.
The more recent skulls from Europe, for instance, showed clear evidence of a Neanderthal influence, along with features of the early modern humans that evolved in Africa. Early modern human skulls from Australia had similarities to the more ancient skulls from Indonesia.
All that suggests modern humans dribbled out of Africa in small numbers and migrated to distant lands where they mingled with a more ancient human type that already lived in those places.
"In other words, we found dual ancestry," Frayer told the Journal-World Thursday during a telephone interview from Italy.
Eventually, the superior genes of modern humans dominated the species through natural selection and the clearly identifiable archaic humans, such as the Neanderthal, disappeared.
"The evidence suggests that there was not a replacement of all human populations. There were contributions from the local groups that had been there for hundreds of thousands of years," Frayer said.
"It's like today. It was a big, breeding world," he said. "Today it happens faster. In the past it took a lot longer to make those connections."
Frayer, a former chairman of the anthropology department, has been with KU for 25 years.
Aside from Frayer, the research team included Milford Wolpoff and Keith Hunley of the University of Michigan and John Hawks of the University of Utah.
Hawks said in a statement released by the University of Utah that "There are still Neanderthals today and they are us. People of European descent are also people of Neanderthal descent."
The conclusion is controversial, and another University of Utah anthropologist, Henry Harpending, said he is unconvinced.
"The genetic evidence is unequivocal in support of the idea that we are all descended from a small group of Africans within the last 100,000 years," Harpending said in a statement. "There is no Neanderthal in us."
The Associated Press contributed to this story.