The ability of Tibetans to live at high altitudes may be due to their DNA

Researchers found 10 genes which help Tibetans thrive at heights where others get sick. Two of the genes are linked to hemoglobin - the substance in blood that transports oxygen round the body. Altitude sickness is the name given to ill-effects caused by the body's struggle to deal with a lack of oxygen at high altitude. It can lead to brain and lung complications, which can threaten even the fittest mountaineers. People native to high altitudes appear to be immune to such effects, through thousands of years of genetic selection.