A set of ancient skulls unearthed in central Mexico's Teotihuacán Valley, found at construction sites in the rapidly growing Mexico City region, are rewriting the history of human colonization in North America.
Geologist Silvia Gonzalez of Liverpool John Moores University in England recently analyzed four of the skulls with help from colleagues at the National Museum of Anthropology in Mexico City, where the bones are housed. She was amazed to find that one of them is 12,700 years old, 700 years more ancient than any human remains ever before found in North America.
That skull, known as Peñon III Woman, has a long, thin shape, dramatically unlike the short, broad form of previous Mexican remains and of today's Native Americans. Most anthropologists believe Native Americans are all descended from a single population that arrived from Siberia. But the Peñon III skull, along with others in the museum collection, does not seem to be related to the Siberian travelers. Rather, they resemble Japan's indigenous Ainu people. Gonzalez believes relatives of the Ainu were part of another, previously unknown wave of immigration that originated in Japan, swept across the Bering Strait, then moved down the west coast of North America and into central Mexico.
Anthropologists have found remains of one modern narrow-headed population, the Pericus, that lived in Baja, California, until going extinct in the 18th century. Gonzalez plans a return trip to Mexico this month to collect DNA samples from Peñon III Woman. She will compare those samples with DNA from Pericu bones to see if the two populations are related. "We need to discard the hypothesis that it was just one massive migration into America. The picture is much more complicated," she says.