Barley Crop Allowed Prehistoric Humans to Survive Tibet's High Altitude

Archaeologists have discovered that humans and plants may have developed unprecedented adaptations to cope with altitude. They've discovered animal teeth, bones and plant remains on the "roof of the world," the Tibetan Plateau.

The new findings suggest that from 3,600 years ago, farming was taking place year-round at unprecedented altitudes. In fact, 53 archaeological sites spanning 800 miles reveal exactly how widespread these practices were at the time.

There's actually evidence of human presence on the Tibetan Plateau that's dated far earlier-about 20,000 years ago. Yet the first semi-permanent villages only appeared about 5,200 years ago. Then, crops and livestock followed even later.

"Until now, when and how humans started to live and farm at such extraordinary heights has remained and open question," said Martin Jones, one of the lead researchers, in a news release. "Our understanding of sustained habitation above 2-3,000 meters on the Tibetan Plateau has to date been hampered by the scarcity of archaeological data available. But our findings show not only did these farmer-herders conquer unheard of heights in terms of raising livestock and growing crops like barley and millet, but that human expansion into the higher, colder altitudes took place as the continental temperatures were becoming colder."

In fact, the new findings raise some interesting questions about human adaptation to such heights. In addition, research on the Tibetan Plateau has raised interesting questions about the timing and introduction of western crops such as barley and corn, which were staples of the so-called "Fertile Crescent." This meeting of the east and west from 4,000 to 3,600 years ago led to the joining or displacement of traditional North Chinese crops of broomcorn and foxtail millet. In this latest study, the researchers found evidence of cereal grains at all 53 of the sites and bones from livestock at 10 of the sites.

"Our current knowledge of agricultural foods emphasizes a relatively small number of crops growing in the intensively managed lowlands," said Jones. "The more we learn about the rich ecology of past and present societies, and the wider range of crops they raised in the world's more challenging environments, the more options we will have for thinking through food security issues in the future."

The findings are published in the journal Science.