|Some Native Americans had Neanderthal roots-expert|
18 (Reuters) - The baffling 9,300-year-old Kennewick Man, whose skeleton
was unearthed in 1996 in Washington state, looks so "European"
because he had Neanderthal roots, a scientist said on Friday.
The National Park Service said earlier this month it would allow a genetic analysis of the skeleton, which some Native American groups claim as an ancestor and want buried.
It has intrigued researchers because the features seem to suggest a more Caucasian than Asian origin. Others say he looks like an Ainu -- the aboriginal people of Japan who are often said to be physically closer to Europeans than Japanese.
Loring Brace, a specialist in bone measurements at the University of Michigan, says he has a simple explanation for this -- both Kennewick Man and the Ainu, along with the people of Europe, descended from Neanderthals.
"I have long maintained that Neanderthals are obviously the ancestors of living Europeans," Brace told a news conference held at the annual meeting of the American Association for the Advancement of Science (AAAS).
"To produce a modern European out of a Neanderthal, all you have to do is reduce the robustness," Brace said. Scale down the heavy teeth, jaws and brow of the Neanderthal and you have a European, he said.
It is a controversial theory because most scientists believe that Neanderthals were an evolutionary dead-end, people who lived side-by-side with the Cro-Magnons who were the earliest Homo sapiens but who did not interbreed with them.
But Loring said his measurements that compare the skulls of people all over the world suggest a resemblance among peoples living in Europe, along the coastlines of Asia and into ancient North America.
He also found two distinct groups among the Native Americans. "It is clear there are two major groups and they are not closely related to each other at all," Brace said.
One group physically more resembles East Asians, especially modern Chinese, while the second looks a lot like the Ainu.
"Some of the Plains Indians don't look Native American at all," Brace said.
He thinks they may have come from the same lineage as Kennewick Man did. Brace has not been allowed to examine the Kennewick remains, but thinks any measurements he could make would support his theories.
Some recent evidence tends to support Brace.
In October an international team of scientists tested Neanderthal bones found in Croatia in the 1970s and found they may be just 28,000 years old, which means they would have lived side-by-side with modern humans for several thousand years.
Erik Trinkaus, an anthropologist at Washington University in St. Louis, led that study and another one that a few months earlier suggested that the 24,500-year-old bones of a child found in Portugal showed characteristics of both Neanderthals and of modern humans.
Trinkaus said he believed this suggested humans and Neanderthals interbred, but Brace said it just as easily could have been an "intermediate" form of human evolving from Neanderthal into modern Homo sapiens sapiens.
Although just a few years ago everyone agreed no humans lived in the New World until about 11,000 years ago, and that everyone trekked together over the Bering Strait into Alaska, more and more evidence suggests that people started coming over in successive waves as long as 30,000 years ago.
David Meltzer, an anthropologist at Southern Methodist University, noted that huge ice sheets would have blocked any passage from the Bering Strait down through Canada until 11,500 years ago.
A settlement in Monte Verde, Chile has been dated to 12,500 years ago, which suggests people must have come either a different way, or long before the ice sheets formed.
Theodore Schurr of the Southwest Foundation for Biomedical research in San Antonio, Texas did genetic studies that found four separate lineages in the Americas, and using a "molecular clock" that tracks the rate of mutations in DNA, dates some of them back as far as 25,000 or 30,000 years ago.
Some seem to originate in southeastern Siberia, while one seems to have links with a relatively rare lineage found in a few modern Europeans.
Johanna Nichols of the University of California-Berkeley, who compared the structures of Native American languages to languages found elsewhere in the world, said some of the similarities when dated using a kind of linguistic clock, could date back to a common ancestral language 30,000 years ago.
One thing is clear, Meltzer said -- when people did reach what is now the continental United States they spread fast, which meant they had to be astonishingly resourceful.
"In the space of 500 years they completely covered the continent," he said. "These folk had no neighbors."
And most modern hunter-gatherers depend heavily on their neighbors for information about the landscape.
The early colonists of the Americas had no one to ask where to find water, food or herbs to cure their ills. And they had few sources of fresh genes. "You can only marry your sister so many times," Meltzer said.