In a groundbreaking discovery, researchers have found that Tibetans were able to adapt to high altitudes because of a gene picked up when their ancestors mated with a species of humans they helped push to extinction.

This is the first time a gene from another human species has been shown unequivocally to have helped modern humans adapt to their environment.

An unusual variant of a gene involved in regulating the body’s production of haemoglobin — the molecule that carries oxygen in the blood — became widespread in Tibetans after they moved onto the high-altitude plateau several thousand years ago.

This variant, called EPAS1, allowed them to survive despite low-oxygen levels at elevations of 15,000 feet or more whereas most people develop thick blood at high altitudes, leading to cardiovascular problems, researchers from University of California, Berkeley, claimed. “We have very clear evidence that this version of the gene came from Denisovans, a mysterious human relative that went extinct 40,000-50,000 years ago, around the same time as the more well-known Neanderthals, under pressure from modern humans,” explained Rasmus Nielsen, professor of integrative biology at UC Berkeley.

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