How is it that Tibetans thrive at 13,000 feet, where those of us born closer to sea level get sick? Scientists now think that Tibetans have evolved while most of the rest of us have stood still:
Recent research shows that Tibetans, who have lived isolated in these high altitudes for thousands of years, enjoy a genetic variation that keeps their hemoglobin levels in a normal range. A variation of EPAS1, a gene that is sometimes associated with increased athleticism, causes an enzymatic change in the way oxygen binds to blood and is transported around the body. Compared to lowland Chinese, Tibetans thrive in high altitude—they do not suffer from chronic altitude sickness and their children are born with normal weight.
“It makes them super athletes at altitude, without a doubt,” says Ken Kamler, a surgeon, author of Surviving the Extremes and an editorial advisor to Popular Mechanics. “I’ve been on climbs with these guys, and I’m maybe a foot taller than some of them, and they carry loads on their backs that I can’t even lift off the ground, and they will carry them way faster than I’m climbing with a much lighter load.”
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