Carl Zimmer, writing in his new column “Matter” for the New York Times:
Life in the mountains is easier for people whose ancestors have lived there for millenniums. They don’t suffer from altitude sickness. Women from high-altitude populations give birth to normal-size babies.
Scientists visiting some of those populations have discovered a number of biological adaptations in the inhabitants’ bodies. In Tibet, for example, people have broader arteries and capillaries. In the Andes, they can dissolve more oxygen into their blood.
Such traits aren’t just found in one location or another, but in several high-altitude areas around the world. The genes responsible, though, differ from region to region.