BOB HIRSHON (host):
The low-oxygen high life…I’m Bob Hirshon and this is Science Update.
As you climb a mountain, air pressure decreases, and the concentration of oxygen goes down. When most people travel to high altitudes, they compensate by producing more hemoglobin, the protein in red blood cells that carries oxygen to the tissues. But too much hemoglobin can lead to chronic mountain sickness. Physical anthropologist Cynthia Beall of Case Western Reserve University says that Tibetans live at high altitudes, but don’t suffer from the condition.
CYNTHIA BEALL (Case Western Reserve University):
One of the ways the have adapted is by having the same level of the oxygen-carrying molecule hemoglobin.
She and her colleagues think a variation in a gene called EPAS1 is responsible. They hypothesize that Tibetans may have enhanced blood flow, or that their cells are more efficient at producing energy, allowing them to survive with less oxygen. I’m Bob Hirshon, for AAAS, the science society.