When did humans first occupy the Americas? Ask the sloth bones
The New York Times reports: Of all the long-running disputes in archaeology, few roil scholars more than the question of when humans arrived in the Americas. For much of the past century, the reigning theory was that in or around 11,500 years ago big-game hunters from Asia trudged to North America across a land bridge spanning the Bering Strait, hung a right through a corridor between glaciers and, in less than a millennium, reached the tip of South America. Over…