Fishing for the first Americans

Archaeology is moving underwater and along riverbanks to find clues left by the people who colonized the New World.

On 17 September, a catamaran will set off into the Pacific Ocean on a week-long cruise back to the Pleistocene. Laden with sonar instruments, the research vessel Shearwater will probe the ocean bottom to find places that were beaches and dry land more than 13,000 years ago, when the sea level was around 100 metres lower. The researchers are hunting for evidence that ancient people lived along this now-sunken coastline as they colonized the New World.

Meanwhile, other archaeologists are digging in the intertidal zone on a remote island off the shore of British Columbia in Canada, where the sea level has barely changed since the ice-age glaciers began to retreat. Since late last year, that team has found footprints and a tool that date back 13,200 years, making them some of the oldest human marks on the continent. Whoever left them had to have reached the island by boat. Welcome to the newest wave of American archaeology: the idea that the first residents of the Americas came by sea, hugging the Pacific coast as they went south.[...] Nature News