COLUMBUS, OHIO—According to a Cosmos Magazine report, Mark Hubbe of The Ohio State University and his colleagues suggest that the peopling of North America may have been a more complex process than previously thought. The researchers analyzed four human skulls recovered from a now underwater limestone cave system in Quintana Roo, Mexico, which have been dated to between 9,000 and 13,000 years old. Hubbe said information collected with CT scans and X-rays revealed that the four skulls had diverse sets of characteristics. The researchers then compared the craniofacial features observed in the four skulls with those of ancient skulls uncovered in South America and others around the world. They concluded that the oldest of the four skulls resembled the skulls of North American Arctic populations, while the other three resembled modern Europeans, Asian and Native American groups, and Arctic populations with some features found in ancient skulls from South America, respectively. “We always assumed that what was happening in South America was true in North America,” Hubbe said. “Now we need to revise that.” For more on how North America came to be populated, go to "America, in the Beginning."