A member of the Xavante tribe of the Brazilian Amazon, where researchers detected genetic traces of Australasian populationsWIKIMEDIA, ELZA FIUZA/ABRNo question is hotter right now in the minds of paleoanthropologists than this: How were the Americas originally populated? Anthropologists have been debating the issue for decades, but with recent advances in ancient DNA analysis, researchers are getting closer than ever to answering the question. As two papers published in Science and Nature this week (July 21) illustrate, the debate is still very much alive.
Both studies detected genetic traces of human populations from Australia and the islands that surround it—an area known as Australasia—in the genomes of modern Native Americans. But the authors of the Science paper could not find a genetic affinity with Australasians in the ancient DNA of Native Americans from Mexico or Patagonia. The two teams interpreted their data differently: Pontus Skoglund of Harvard Medical School and coauthors wrote in Nature that the Americas may have been peopled by a diverse set of founding populations, offering the Australasian signal as evidence that humans may have arrived in the Americas in different pulses; an international team led by the University of Copenhagen’s Eske Willerslev posited in Science, meanwhile, that people crossed into North America via the Bering ...
