Tibetans Underwent Fastest Evolution Seen in Humans
Life at high altitudes forced ancient Tibetans to undergo the fastest
evolution ever seen in humans, according to a new study.
The most rapid genetic change showed up in the EPAS1 gene, which helps
regulate the body's response to a low-oxygen environment. One version,
called an allele, of the EPAS1 gene changed in frequency from showing up
in 9 percent of the Han Chinese to 87 percent of Tibetans.
Such genetic changes suggest Tibetan ancestors split off from the Han
Chinese population about 2,750 years ago, researchers say. But only
those most evolutionarily suited for life at high altitudes survived
when they moved to the Tibetan Plateau.