Researchers may have discovered remnants of the earliest-known human habitation at a high altitude.
Scientists looked at animal teeth and bones as well as plant remains on the Tibetan Plateau that indicate crops were grown and livestock were raised year-round in the region as far back as 3,600 years ago, the University of Cambridge reported.
The first semi-permanent villages were erected on what is referred to as the "roof of the world" about 5,200 years ago. Until now researchers were not sure how humans learned to live at such extreme heights such as the Tibetan Plateau, which sits at an altitude of between 8,200 and 11,154 feet above sea level.
The recent findings revealed that humans not only figured out a way to move to these altitudes and run farms, but did so as temperatures were getting steadily colder.
"Year-round survival at these altitudes must have led to some very challenging conditions indeed - and this poses further, interesting questions for researchers about the adaptation of humans, livestock and crops to life at such dizzying heights," said Professor Martin Jones, from Cambridge's Department of Archaeology.
The findings also bring to question when crops, such as barley and wheat, were introduced to the region after being imported from the west. Across the plateau the researchers identified real grains ("foxtail millet, broomcorn millet, barley and wheat") at all 53 sites examined and animal bones and teeth ("from sheep, cattle and pig") were discovered at ten of the sites. The earlier group of these artifacts dated back between 3,600 and 5,200 years and reached an elevation of about 8,300 feet; another group was dated at between 2,300 and 3,600 years ago and reached elevations as high as 11,150 feet.
"Our current knowledge of agricultural foods [emphasizes] a relatively small number of crops growing in the intensively managed lowlands. 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 were published in a recent edition of the journal Science.
