Skip to Content

Genetic Adaptations to High Altitude

Tibetans possess genetic variations that may protect against altitude sickness.

The atmosphere surrounding the mountain villages in the high peaks of Tibet, which stretch about 14,000 feet above sea level, contains 40 percent less oxygen than the air at sea level. That harsh environment has felled many avid mountain climbers, but the long-time inhabitants of the high peak mountain villages seem to thrive in the thin air. New genetic analysis of this population is starting to explain why.

A climber on Mt Everest. Credit: Jing Wang

Scientists from the University of California, Berkeley sequenced the exomes–the three percent of the genome that codes for proteins–of 50 Tibetans and 40 Han Chinese, uncovering more than 30 genes with DNA mutations that have become more prevalent in Tibetans than Han Chinese. Nearly half of these genes help regulate how the body uses oxygen, according to the study, published today in the journal Science. Scientists say the results illustrate the most recent example of natural selection in humans.

One particularly widespread mutation in Tibetans–it is present in fewer than 10 percent of the Han Chinese and nearly 90 percent of all Tibetans–lies near a gene called EPAS1. (A second study in the same issue also picked up this variant.) Earlier research suggests this gene plays a role in regulating hemoglobin in response to oxygen. According to Rasmus Nielsen, a professor of integrative biology at Berkeley who led the statistical analysis for one of the studies, this gene was dubbed “super athlete gene” when it was first identified several years ago because some variants are associated with improved athletic performance.

People with two copies of the gene living at high altitude have fewer red blood cells and lower hemoglobin levels than those with one or no copies. The finding may explain in part Tibetans’ resistance to mountain sickness; when people living at sea level travel to high altitudes, their bodies compensate for the low oxygen by making more red blood cells. That makes the blood more viscous, making it difficult to oxygenate tissue and increasing risk of thrombosis and miscarriage. It’s not yet clear how people with two copies of the variant cope with lower hemoglobin levels, though they appear to have similar oxygen levels to those without the mutation.

Keep Reading

Most Popular

conceptual illustration of a heart with an arrow going in on one side and a cursor coming out on the other
conceptual illustration of a heart with an arrow going in on one side and a cursor coming out on the other

Forget dating apps: Here’s how the net’s newest matchmakers help you find love

Fed up with apps, people looking for romance are finding inspiration on Twitter, TikTok—and even email newsletters.

computation concept
computation concept

How AI is reinventing what computers are

Three key ways artificial intelligence is changing what it means to compute.

still from Embodied Intelligence video
still from Embodied Intelligence video

These weird virtual creatures evolve their bodies to solve problems

They show how intelligence and body plans are closely linked—and could unlock AI for robots.

We reviewed three at-home covid tests. The results were mixed.

Over-the-counter coronavirus tests are finally available in the US. Some are more accurate and easier to use than others.

Stay connected

Illustration by Rose WongIllustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.