Is there a Genetic Basis for Adapting to Life at High Altitudes? A team of scientists from the United States and China set out to answer these questions. They began their search for a genetic basis for high-altitude hardiness by looking for genes that differed between the Tibetan people and closely related, but low-dwelling, neighbors. They collected DNA sequence data from 50 Tibetans and 40 nearby Chinese low-dwellers. For comparison, the scientists also collected DNA sequence data from 200 low-dwelling Danes, a more distantly related population.