8000-Year-Old Tibetan Mutation Linked to Human Life at High Altitudes

It turns out that a genetic mutation may allow humans to survive better at high altitudes. Scientists have discovered that Tibetans, who thrive in the thin air of the Tibetan Plateau, may have a single DNA base pair change that dates back 8,000 that could explain how they adapt to thin air.

"These findings help us understand the unique aspects of Tibetan adaptation to high altitudes, and to better understand human evolution," said Josef Prchal, senior author of the new paper, in a news release.

The researchers took samples from 90 Tibetan volunteers, both from the U.S. and abroad. Their DNA had a fascinating tale to tell. Scientists found that about 8,000 years ago, the gene EGLN1 changed by a single DNA base pair and today, about 88 percent of Tibetans have this genetic variation.

So what does sort of advantage does this mutation give to Tibetans? In those without the adaptation, low oxygen causes their blood to become thick with oxygen-carrying red blow cells in an attempt to feed starved tissues. This can cause long-term complications such as heart failure. Yet the genetic variation protects Tibetans by decreasing the over-response to low oxygen. This allows Tibetans to better survive and thrive in the thin air of the plateau.

Yet while researchers now know that this genetic adaptation exists, they're interested in finding out what other changes in the body it might cause. Not only that, but it's likely that there are other genetic changes that have occurred in order to support life at high altitude.

"There is much more that needs to be done, and this is just the beginning," said Prchal.

The findings represent a good start when it comes to understanding the evolutionary changes that have occurred to allow people to better thrive in high altitude environments. By examining DNA and the people that live in different environments, scientists can better understand how evolution plays a role in humans.

The findings are published in the journal Nature Genetics.