Archaeologists found that hunter-gatherers might have lived permanently in the Tibetan Plateau at least 7400 years ago. This is nearly 4000 years earlier than researchers previously thought.
The footprints were found at a site called Chusang, northwest of Lhasa, in central Tibet. So far experts believe that people began to live there about 3600 years ago, when barley crops that can tolerate frost and cold temperatures were introduced, and farmers moved upland. Footprints were found in rocks that were once soft mud near a hot spring. They involve marks of at least six individuals, including some children. Researchers discovered, through application of various techniques, that sediments around the prints are between 7400 and 12700 years old.
The new finds seem to fit genetic studies, which have shown that the modern Tibetan gene pool was largely shaped between 15000 and 9000 years ago. Other studies have also suggested that Tibetans began to acquire genetic mutations that protected them from low blood oxygen levels between 12800 and 8000 years ago. Experts believe that even if humans lived on the plateau permanently that early, it would have been a marginal existence involving only a small number of people as a large population could not have survived on the plateau year-round without agriculture.
(after Nature & Smithsonian)