New discoveries are starting to create a clearer picture of how and when the first people arrived in the Western Hemisphere. The generations-old theory that Indians crossed from Asia to Alaska via a land corridor (Beringia) that opened up when growing glaciers lowered sea levels, is now widely being augmented by other theories that people in boats may also have migrated east as well.
Vance T. Holliday, a professor of anthropology and geosciences at the University of Arizona, organized a panel of scientists at the just-concluded meeting of the Geological Society of America, held in Seattle. Panel members offered new research information about archaeological and geological finds showing that the west coast of the Americas offered significant resources - fish, shellfish, birds and mammals smaller than mastodons - for those who could take advantage of them.
Holliday says Beringia is still viewed as the likely migration route from Asia. The question is whether people entered the New World by traveling from the interior of Beringia through the mountains over to the far northern Great Plains, and then down the Plains east of the Canadian Rockies to the glacier-free interior of the continent.
This would have happened when the great ice sheets that once covered Canada started retreating, either into the Canadian Rockies or into the Hudson Bay Lowland. These two sheets merged just east of the Rockies and so would have separated in this area.
"In the early days of radiocarbon dating it seemed that the opening of the 'Ice Free Corridor' coincided with the arrival of the first well-established human occupation, the so-called Clovis culture," Holliday said. "Scientist began wondering if perhaps the corridor was all that hospitable, and also there are questions about exactly when it opened. This got people to thinking about a coastal route."
Holliday, an authority on the archaeology of the Great Plains, told the National Geographic that "Recent findings have made it clearer that regional climate and geography played a much larger part in early migration patterns than previously thought, and increases the likelihood that people arrived using a coastal route."
The possibility of humans using a coastal route, for instance, might help explain why the 12,000-year-old Monte Verde site in southern Chile predates the earliest Clovis sites by about 1,000 years. Clovis is the generalized name for the oldest well-documented inhabitants of North America, often characterized as hunters of large ice-age mammals.
The complete article can be found online at the National Geographic Web site.