First Americans may have arrived 40,000 years ago
February 17, 1998
Web posted at: 4:23 a.m. EST (0923 GMT)
PHILADELPHIA (Reuters) -- Linguistic and physical evidence is mounting to show that the first Americans migrated from Asia not 10,000 or 20,000 years ago but as many as 40,000 years ago, experts said Monday.
The first people to make the trek across what is now the Bering Strait from Asia into Alaska may have arrived even before the last Ice Age covered North America with glaciers, they said.
The discovery of a site apparently 12,500 years old in Monte Verde, Chile, has thrown the archeological world into an uproar. The site itself is 1,300 years older than the oldest known previous site -- and it is 10,000 miles away from the onetime land bridge between Asia and Alaska.
Unless the settlers went dashing straight down to Chile, they must have been on the continent for tens of thousands of years, researchers told the annual meeting of the American Association for the Advancement of Science.
Johanna Nichols, a language expert at the University of California at Berkeley, said computer models could show how long it would take people to physically move from Alaska to Monte Verde.
"That's about 8,000 miles once one crossed the ice sheet," she said. "It would have taken about 2,000 years to travel on a beeline at a good clip."
That would put the first settlers at 14,500 years ago at the very latest.
Geological experts point out that heavy glaciers covered much of the continent at that time, so in fact the trek must have taken place much earlier.
Key could be in linguistics
Some of the most compelling evidence is linguistic, said Nichols. Native North American languages are so different that they must have evolved over tens of thousands of years.
"The linguistic population of the New World is 40,000 years old or something like that," Nichols said.
"There are 130 to 150 different (language) families in Native American languages today," Nichols told a news conference. An example of a language family is Indo-European, which includes languages as far apart as English, Russian and Sanskrit.
It takes such a family about 6,000 years to evolve. "So there are something like 140 of these 6,000-year-old different units existing among Native Americans," Nichols said.
"The large number of distinct language families historically attested in the Americas ... is far more than could have descended from one ancestor in 14,500 years."
Even if people had migrated into the Americas constantly over time, without any interruptions by glaciers, it would have taken 30,000 years for that many groups to develop, she estimated.
There was probably a second influx, she added. There is a narrow strip of different language families along the west coast of the Americas which matches patterns found only in other Pacific Rim countries.
"They are 12,000 years old, but certainly not 40,000," she said.
Physical measurements could determine age of 1st Americans
Rob Bonnichsen of Oregon State University said his team might eventually be able to answer the question of how old the first Americans are with physical measurements.
They have found naturally shed human and animal hair at ancient sites and have been able to tease DNA out of it. They have also used new carbon-dating methods on the animal hair, and it seems to work.
"We can extract and amplify DNA from an individual hair," he said. "We can DNA analyze and carbon-date the same hair."
His team has already tried the method on a 9,500-year-old hair from a mountain sheep -- they want to perfect the methods before they try it on a precious human sample.
Dennis Stanford of the Smithsonian Institution in Washington, D.C. said he thought more and more evidence would come out about very early Americans. Scientists who had sites they thought were older than 10,000 years had been afraid to come forward for fear of being criticized, he said.
"Now a number of sites are coming to light," he said. "I would predict that in the next year there would be even more."
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