tibet denisovans
© National GeographicA team excavates at the Nwya Devu site on the Tibetan Plateau.
People were living 4,600 metres above sea level on the Tibetan Plateau at least 30,000 years ago, a new study has found.

That makes it the earliest known human occupation at high altitude anywhere on the planet.

Archaeologists have long wondered when humans moved up to the "roof of the world", which also happens to be one of the least hospitable places on Earth, but hard evidence has been scant.

Now researchers from China, the US and Russia have found some.

In a paper published in the journal Science, a team led by Xiaoling Zhang from the Chinese Academy of Sciences in Beijing reports uncovering thousands of stone artefacts, including advanced blades, at the site known as Nwya Devu in central Tibet.

This suggests it was used as a workshop for manufacturing tools. And, as similar stone technologies were not common in northern China, the researchers also believe the earliest Tibetans interacted with contemporaries from Siberia and Mongolia.

Stone Artefacts
© Zhang et alArtefacts reveal that the Tibetan plateau was settled much earlier than thought.
Dating from 40,000 to 30,000 years ago, Nwya Devu, which was discovered in 2013, is the highest Paleolithic archaeological site yet identified globally.

Until now, estimates of when humans moved to the region have converged around 11,000 years ago, when agriculture started to emerge, or 15,000 years, when hunter-gatherers began to move into higher areas in summer.

Here, too, Zhang and colleagues have something new to add to the mix.

The Tibetan Plateau may be one region through which humans with Denisovan DNA in their genomes diffused to the south, they suggest, contributing an enhanced ability to adapt to the rigours of the high-altitude environment.
Nwya Devu Tibet
© John OlsenNear the archaeological site of Nwya Devu on the Tibetan Plateau
All of which doesn't answer why people would choose to move to such an inhospitable place at a time when land was hardly at a premium. The answer is food.

Comment: Don't get ahead of yourselves there! An answer may be food. Raging catastrophe all around may be another.

In a complementary commentary also published in Science, Zhang and Robin Dennell from the UK's University of Exeter note that Paleolithic hunters would no doubt have been attracted by herds of gazelles, horses and yaks, and possibly a woolly rhinoceros or two.

"The Plateau was undoubtedly harsh, but it was not barren," they write.