It’s not easy living thousands of meters above sea level. The air holds less oxygen, there’s more harmful ultraviolet (UV) radiation from the sun, and food supplies vary dramatically from season to season. But that doesn’t stop nearly 5 million people from living on the Tibetan Plateau, the world’s highest at an average of 4000 meters. Now, scientists working with the largest-ever sample of Tibetan genomes have discovered seven new ways in which Tibetan genes have been tweaked to cope with high altitude, resulting in higher body mass index (BMI) and a boost in the body’s production of the vitamin folate.[Source]