Some people in the Brazilian Amazon are very distant relations of indigenous Australians, New Guineans and other Australasians, two groups of scientists who conducted detailed genetic analyses reported Tuesday. But the researchers disagree on the source of that ancestry.
The connection is ancient, all agree, and attributable to Eurasian migrants to the Americas who had some Australasian ancestry, the scientists said.
But one group said the evidence is clear that two different populations came from Siberia to settle the Americas 15,000 or more years ago. The other scientific team says there was only one founding population from which all indigenous Americans, except for the Inuit, descended and the Australasian DNA came later, and not through a full-scale migration. For instance, genes could have flowed through a kind of chain of intermarriage and mixing between groups living in the Aleutian Islands and down the Pacific Coast.
David Reich of Harvard, the senior author of a paper in the journal Nature, said the DNA pattern was “surprising and unexpected, and we weren’t really looking for it.”
Pontus Skoglund, a researcher working with Dr. Reich who was investigating data gathered for previous research, found the pattern, or signal, as he described it. He and Dr. Reich and their colleagues used numerous forms of analysis, comparing different groups to see how distant they were genetically, to determine if there was some mistake.
But, Skoglund said, “we can’t make it go away.”
The GLP aggregated and excerpted this blog/article to reflect the diversity of news, opinion and analysis. Read full, original post: Scientists Trace an Ancient Connection Between Amazonians and Australasians
