It took the arrival of western cereal grains, particularly barley, for humans to establish permanent residence above 3,000 meters on the Tibetan Plateau, researchers say. Despite evidence of intermittent human settlements in the region dating back to at least 20,000 years ago, Fahu Chen and colleagues say that humans didn’t get a solid foothold there -- the so-called “roof of the world” -- until about 5,200 years ago.
↧