Human Variation & Race
Environmental Stress: High Altitude The mechanisms that maintain homeostasis evolves at lower altitudes, and for the populations that live in altitudes of 10,000 15,000 and even 17,000 feet above sea level their bodies faces stress that negatively impacts the body. These stresses include hypoxia (a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level), alternating daily extremes of climate that range from hot days to freezing nights, lower air pressure and aridity (characterized by a severe lack of available water, to the extent of hindering or preventing the growth and development of plant and animal life). Four ways humans have adopted to this stress Short Term: Increase of breathing and doubled heart rate. Due to the decrease in amount of oxygen available in higher altitudes, the bodies first response is to increase heart rate to pump oxygen to cells. Facultative: Increased red blood cells. The longer time a perso
