1. One of the environmental stresses I chose was high altitude. This environmental stress has negatively impacts the survival of humans by disturbing homeostasis is that there are the alternating daily extremes of climate that often range from hot, sunburning days to freezing nights and are often strong and humidity low, resulting in rapid dehydration. Another environmental stress has negatively impacts the survival of humans by disturbing homeostasis is that the air pressure is lower which means this is usually the most significant limiting factor in high mountain regions. When we breathe in air at sea level, this causes oxygen to easily pass through selectively permeable lung membranes into the blood. At high altitudes, the lower air pressure makes it difficult for oxygen to enter our vascular systems. The result is hypoxia or oxygen deprivation. Hypoxia usually begins with the inability to do normal physical activities, such as climbing a short flight of stairs without fatigue. Other early symptoms of "high altitude sickness" include a lack of appetite, vomiting, headache, distorted vision, fatigue, and difficulty with memorizing and thinking clearly. In very urgent cases, pneumonia-like symptoms due to hemorrhaging in the lungs and an abnormal accumulation of fluid around the brain (cerebral edema) develop. There is also an increased risk of heart failure due to the added stress placed on the lungs, heart, and arteries at high altitudes. When we travel to high mountain areas, our bodies initially develop inefficient physiological responses. There is an increase in breathing and heart rate to as much as double, even while resting. Pulse rate and blood pressure go up sharply as our hearts pump harder to get more oxygen to the cells. These are stressful changes, especially, for people with weak hearts. Furthermore, a more efficient response normally develops as acclimatization takes place. More red blood cells and capillaries are produced to carry more oxygen. The lungs increase in size to facilitate the osmosis of oxygen and carbon dioxide. There is also an increase in the vascular network of muscles which enhances the transfer of gases.
2. One specific adaptation I chose was cultural because there is a debate about how much of this type of adaptation receives genetic influence, but these traits can include use of tools, diet, social practices, reproductive behaviors, migratory patterns, and clothing styles. The first way in which humans have adapted to this stress was increasing their fitness level after successful acclimatization to low oxygen pressure. The second way in which humans adapted to this stress was on returning to sea level after successful acclimatization to high altitude, the body usually has more red blood cells and greater lung expansion capability than needed. The third way in which humans adapted to this stress was the rate of miscarriages is usually higher at altitudes above two miles because fetuses receive less oxygen from their mothers. The fourth way in which humans adapted to this stress was the physiological changes that result in increased fitness are short term at low altitude and in a matter of weeks, the body returns to a normal fitness level.
3. The benefits of studying human variation of this perspective across environmental clines is that I learned a good amount of new information about high altitudes that I didn't know of, but now that I know it very interesting to me about the environmental issues that can happen due to high altitudes especially the health affects. This information from explorations like this can be useful to help us in any way of avoiding these health affects. An example is avoiding to breathe in air at sea level because it causes oxygen to easily pass through selectively permeable lung membranes into the blood.
4. I would use race to understand the variation of the culture adaptation by people of different races have different culture adaptations such as the different tools they use, a variety of diets and different foods, various social practices, and particular clothing styles. The study of environmental influences on culture adaptations is a better way to understand human variation than by the use of race because environmental stress has negatively impacts in many different cultures and races.
