This may be one of my favorite science stories in years. Researchers have concluded that the “superathlete” gene that helps Sherpas and other Tibetans thrive at high altitudes is actually traced to an ancient species of human, the Denisovans. The gene, EPAS1, regulates the body’s production of hemoglobin, and was acquired from the Denisovans. Of course, the Denisovans went extinct some 40,000 years ago so for those creationists who insist that the Earth is only a few thousand years old . . . you might want to move on to the next story.
The Denisovans mated with the ancestors of Europeans and Asians and then disappeared. The researchers focused on a difference between Sherpas and other high-altitude people like Andean highlanders who have adapted to thin air in a way that adds more oxygen-carrying hemoglobin to their blood. However, Tibetans have less hemoglobin in their blood, which avoids some problems like clots and strokes. The reason appears to be the Denisovans. The ancestors of Tibetans and Han Chinese got the gene when they mated with Denisovans. However, many of the descendants did not need the gene and eventually lost the EPAS1. However, it was the Tibetans who settled on the high-altitude Tibetan plateau and therefore favored the genes’ continuation.
Source: Science Mag