ABOVE: Team members enter the Chiquihuite cave.
DEVLIN A. GANDY
Between 26,500 and 19,000 years ago, massive sheets of ice covered Earth’s Northern hemisphere. During this so-called last glacial maximum, the ice sequestered water, causing a drop in sea level and exposing land that connected northeast Asia and northwest North America near present-day Alaska. In what is now Canada, two glaciers merged and covered the region with ice thousands of feet thick that stretched from the Atlantic to the Pacific. At least 13,000 years ago, those glaciers started to recede, opening up an ice-free corridor that is thought to have been used by early humans who came down from northeast Asia and populated what is now the United States.
In a study published today (July 22) in Nature, researchers describe stone artifacts found in Chiquihuite Cave in northern Mexico that date to the last glacial maximum. For humans to be present ...
