Saturday, August 31, 2019

North American prehistory -- keeps getting older


Know how these differ from Clovis points?  Well, they do.
Recent data from an archaeological site in Idaho sets out new evidence for a "pre-Clovis"  (ie, more than 12,000-13,000 years before the present) presence in western North America.

"Clovis" is largely a style of tool-making, with examples found quite widely in North American excavations back to 13,000 BP. It was long considered the oldest evidence of human presence in the Americas. There are now also some genetic data from Clovis-associated remains, which confirm Clovis people shared DNA links with other early North Americans and also with Asian/Siberian forebears.

A "Clovis" presence was compatible (just barely, maybe) with an "ice-free" deglaciated corridor east of the Rocky Mountains that could have given the first Clovisans access from Beringia and Asia into North America as the ice sheets began to recede. But human evidence south of the ice 16,000 years ago is too early for any "ice-free" corridor. So finds that date earlier strengthen the likelihood of a coastal or sea-borne migration into the Americas coming first, followed by dispersal inland from points south of the ice-sheet barrier. The archaeologist at Cooper's Ferry, Idaho, notes that the site might have been accessed by a route opening inland from the Pacific Coast more or less where the lower Columbia River now flows.

I made a documentary, 'Peopling the Americas,' for CBC Radio Ideas as long ago as 1989, and even then the best glaciological opinions I could find were dubious about an ice-free corridor as early as the archaeologists needed, and intrigued by the likelihood of a coastal migration, along a Pacific coast that might have resembled 20th century Greenland -- cold, but habitable and traversable.  Nice to see the evidence grow.

Image: from Nature.com.
 
Follow @CmedMoore