Anyone interested in the ongoing debates about human migration into the Americas may want to take a look at a recent news article at Science Daily, New Ideas About Human Migration From Asia To Americas. The article reports on a recent study by Ripan Malhi and colleagues at the University of Illinois published in the Public Library of Science.
The following is from the Science Daily article:
“What puzzled them originally was the disconnect between recent archaeological datings. New evidence places Homo sapiens at the Yana Rhinoceros Horn Site in Siberia – as likely a departure point for the migrants as any in the region – as early as 30,000 years before the present, but the earliest archaeological site at the southern end of South America is dated to only 15,000 years ago.
“These archaeological dates suggested two likely scenarios,” the authors wrote: Either the ancestors of Native Americans peopled Beringia before the Last Glacial Maximum, but remained locally isolated – likely because of ecological barriers – until entering the Americas 15,000 years before the present (the Beringian incubation model, BIM); or the ancestors of Native Americans did not reach Beringia until just before 15,000 years before the present, and then moved continuously on into the Americas, being recently derived from a larger parent Asian population (direct colonization model, DCM).
“Thus, for this study the team set out to test the two hypotheses: one, that Native Americans’ ancestors moved directly from Northeast Asia to the Americas; the other, that Native American ancestors were isolated from other Northeast Asian populations for a significant period of time before moving rapidly into the Americas all the way down to Tierra del Fuego.
“Our data supports the second hypothesis: The ancestors of Native Americans peopled Beringia before the Last Glacial Maximum, but remained locally isolated until entering the Americas at 15,000 years before the present.”
“The team’s findings appear in a recent issue of the Public Library of Science in an article titled, “Beringian Standstill and Spread of Native American Founders.”