Complex Old World Origins Of First Americans Revealed In Analysis Of Prehistoric And Modern Skulls

ANN ARBOR --- Analyzing craniofacial measurements of old and new skulls from around the world, University of Michigan anthropologists have confirmed the complex origins of Native Americans that have been suggested by recent archeological and genetic studies.

In a seminar Friday (Feb. 18) on the initial peopling of the New World, held at the annual meeting of the American Association for the Advancement of Science in Washington, D.C., U-M anthropology Prof. C. Loring Brace presented a craniofacial perspective on the origins of today's American Indians. Using morphometric comparisons of thousands of ancient and modern skulls, collected over a period of 20 years and containing new data from Mongolia that became accessible just last summer, Brace showed how the native inhabitants of the Western Hemisphere fit into several different groups based on craniofacial patterns.

For the analysis, Brace and colleagues compared a battery of two dozen measurements made on each skull to generate a "dendrogram," a tree-like figure in which the distance between the twigs reflects the closeness or distance between any given group and the others.

Their studies show that descendants of the first humans to enter the New World, including natives of Mexico, Peru, and the southern United States, have no obvious ties to any Asian groups. "This could be because they have been separated from their Asian sources for the longest period of time," says Brace. "We hope that new samples from Novosibirsk, Moscow, and Saint Petersburg, which we've recently been given permission to measure, will illuminate their origins."

A second group---including the Blackfoot, Iroquois, and other tribes from Minnesota, Michigan, Ontario, and Massachusetts---was descended from the Jomon, the prehistoric people of Japan. The Inuit appear to be a later branch from that same Jomon trunk. Tribal groups who lived down the eastern seaboard into Florida share this origin, according to Brace.

Another group, originating in China and including the Athabascan-speaking people from the Yukon drainage of Alaska and northwest Canada, spread as far south as Arizona and northern Mexico. "Their craniofacial configuration allies them more closely to the living Chinese than to any other population in either hemisphere," Brace notes.

To refine the linkages and identify the ultimate origins of these peoples, Brace emphasizes that additional analyses need to be performed, using new samples located in institutions in the former Soviet Union, from sites in Mongolia, Siberia, and Eurasia. These samples represent the remaining large block of the world not currently covered in any detail by the U-M Museum of Anthropology craniofacial database.

But he also makes it clear that one firm conclusion has already emerged. "The 'native' inhabitants of the Western Hemisphere are not all minor variants of the same people," he says.