What critical physiological trait allows yaks to scavenge oxygen efficiently in thin air?
Their hemoglobin exhibits a specific characteristic allowing it to bind oxygen more readily at low partial pressures.
The efficiency with which yaks handle hypoxia is deeply tied to modifications in their circulatory system, specifically their hemoglobin. While yaks have a high concentration of red blood cells and hemoglobin overall, the most crucial factor enabling them to survive and exert themselves in thin air is that their specific hemoglobin structure allows it to bind oxygen much more effectively when the partial pressure of oxygen is low. This adaptation permits the efficient scavenging of the limited oxygen available at extreme altitudes, a function that typical lowland bovines cannot replicate, leading them to suffer altitude sickness above 3,000 meters.
