Researcher Silvia Gonzalez examines a 13,000-year-old skull. (Liverpool John Moores University)
The oldest human remains found in the Americas were recently "discovered" in the storeroom of Mexico's National Museum of Anthropology. Found in central Mexico in 1959, the five skulls were radiocarbon dated by a team of researchers from the United Kingdom and Mexico and found to be 13,000 years old. They pre-date the Clovis culture by a couple thousand years, adding to the growing evidence against the Clovis-first model for the first peopling of the Americas.
Of additional significance is the shape of the skulls, which are described as long and narrow, very unlike those of modern Native Americans.
Joseph Powell, a physical anthropologist at the University of New Mexico, cautions that other explanations for the skull shape differences must be considered before jumping to conclusions about origins. "Natural selection or some other microevolutionary forces may play a role. People change when their diets change. This happened in China, for example. Ancient Chinese don't really look much like modern Chinese from the same area. It's a worldwide phenomena and it may be related to the changes at the end of the Ice Age."
Paleoindian specialist Kenneth Tankersley believes archaeology is only beginning to scratch the surface of the debate. "Variation in the languages and DNA of American Indians not only suggests there were multiple migrations from a number of different homelands, but they imply that the first wave of people arrived in the Americas more than 30,000 years ago. This suggests archaeologists should be looking in older geological strata."
DNA evidence might be the best way to know where the first Americans came from and how or why they changed over time. The researchers have planned DNA tests, though successful extraction from remains this old is challenging.--COLLEEN P. POPSON