Human Variation: High Altitude

            High altitude affects many people, past and present, around the world. Often, high altitudes have dangerous effects on people who are not used to it. It may cause hypoxia in many people due to the lack of oxygen that is being supplied to the lungs (There is not less oxygen at higher altitudes, it is just less concentrated). This is because as the altitude increases, air pressure decreases making it harder for oxygen to permeate the lung membrane. Among others, consequences include difficulty breathing, headaches, vomiting, and fatigue. Fortunately, our bodies have been perfecting ways to deal with the stress of changing altitudes.

            Short-term adaptions to hypoxia and other altitude sicknesses are vomiting, fatigue, and headaches. As our bodies are receiving less oxygen, they do their best to compensate and, in turn, indulge minor pains (like the headaches) rather than something more severe like death. This is considered a short-term adaption because the symptoms of altitude sickness disappear once the person suffering returns to his or her normal environment.

            A developmental adaption to high altitude is the increased production of hemoglobin in the blood. The high level of hemoglobin in blood permits higher levels of oxygen to be transported to the lungs, in addition to increasing lung expansion. After hundreds of generations of dealing with the lack of oxygen, Tibetans have perfected this development from birth, resulting in rosy cheeks. People who have lived at high altitudes for many generations will certainly have redder cheeks from birth than those who have only lived there for a short time.

            A facultative response to high altitude is heightened fitness. Many athletes training for the Olympics are often coached at much higher altitudes than their normal environments, because they believe it will result in a “short-term developmental” adaption. As discussed above, with lower oxygen levels and air pressure cause hemoglobin production to increase. This process allows athletes to gain a normal fitness standard while at higher altitudes, and consequently enhanced fitness at lower altitudes. However, their bodies have not been structured to continue doing this like Tibetans and their enhanced fitness soon fades back to normal.

            A cultural adaptation to high altitude is the practice of yoga and meditation by Nepalese Buddhist monks. The deep breathing helps transport oxygen to the lungs at a normal rate. Studies by the High Altitude Medical Research Centre have concluded that yoga and deep breathing can reduce the effects of hypoxia in those who practice it regularly.

            Studying human variation from this perspective allows us to understand how our bodies adapt and function under different conditions. Scientists can see how bodies adapt to the different environments and further understand what the environments may have been like in the past. These studies also indicate that race would have no explanation for the genetic changes seen across environmental clines. The changes that have occurred genotypically and phenotypically are results of people living in an area for a long period of time, regardless of who they were "racially." Race is a poor way to study adaptations, because there are so many similarities between racial groups. Race itself is made up in order to describe people who look different from one another, although there is more genetic variation within a single racial group than between multiple. Environmental stresses are the best way to understand the causes for skin color and many other genetic variations seen around the world.