Humans in America 30,000 years ago, far earlier than thought

Tools excavated from a cave in central Mexico are strong evidence that humans were living in North America at least 30,000 years ago, some 15,000 years earlier than previously thought, scientists said Wednesday. Artefacts, including 1,900 stone tools, showed human occupation of the high-altitude Chiquihuite Cave over a roughly 20,000 year period, they reported in two studies, published in Nature. "Our results provide new evidence for the antiquity of humans in the Americas," Ciprian Ardelean, an archeologist at the Universidad Autonoma de Zacatecas and lead author of one of the studies, told AFP. "There are only a few artefacts and a couple of dates from that range," he said, referring radiocarbon dating results putting the oldest samples at 33,000 to 31,000 years ago. "However, the presence is there." No traces of human bones or DNA were found at the site. "It is likely that humans used this site on a relatively constant basis, perhaps in recurrent seasonal episodes part of larger migratory cycles," the study concluded. The stone tools -- unique in the Americas -- revealed a "mature technology" which the authors speculate was brought in from elsewhere. The saga of how and when Homo sapiens arrived in the Americas -- the last major land mass to be populated by our species -- is fiercly debated among experts, and the new findings will likely be contested...MORE