April 4, 2008
New Evidence Resets Timeline for North American Settlement
DNA from fossil feces discovered by an international team in south-central Oregon is providing the strongest new evidence that humans inhabited North America up to 1,000 years earlier than previously suspected.
Found in Oregon's Paisley Caves, the samples date back over 14,000 years "“ 1,000 years before the Clovis culture.Archaeologist Dennis L. Jenkins of the University of Oregon was a part of the team that discovered the 14 fecal fragments. He said they were able to find very few artifacts in the cave, which causes him to believe that the people traveled often, possibly in search of food.
"We found a little pit in the bottom of a cave," said Jenkins.
"It was full of camel, horse and mountain sheep bones, and in there we found a human coprolite."
The findings give researchers a better idea of what kind of foods the early Americans ate. So far, they've identified bones of squirrels, bison hair, fish scales, protein from birds and dogs and the remains of plants such as grass and sunflowers.
However it was the human mitochondrial DNA that caught researchers' attention the most.
"The Paisley Cave material represents, to the best of my knowledge, the oldest human DNA obtained from the Americas," said co-author Eske Willerslev, director of the Centre for Ancient Genetics at Denmark's University of Copenhagen. "Other pre-Clovis sites have been claimed, but no human DNA has been obtained."
After several genetic studies performed different laboratories, the DNA was found to be that of ancient cave-dwelling humans who were most closely linked to indigenous Siberia and East Asia ethnic groups.
It is believed that humans traveled to North America from Asia over a land bridge between Alaska and Siberia.
"We are not saying that these people were of a particular ethnic group. At this point, we know they most likely came from Siberia or Eastern Asia, and we know something about what they were eating, which is something we can learn from coprolites. We're talking about human signature," Jenkins said.
"If you are looking for the first people in North America, you are going to have to step back more than 1,000 years beyond Clovis to find them," Jenkins said.
"The first humans either had to walk or sail along the American west coast to get around the ice cap," said Willerslev. "That is, unless they arrived so long before the last ice age that the land passage wasn't yet blocked by ice."
University of California scholar David Smith said that the new evidence provides the burden of proof necessary to end debate over whether or not Clovis people were the first American inhabitants.
"If this doesn't convince what's left of the 'Clovis first' people, it should," Smith said in the journal Science.
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