Tuesday, June 3, 2014

Week 8: Human Variation & Race

11.      High altitude has multiple effects on humans. The first issue being the constant climate changing from extreme heat and extreme cold. The more common issue though is the result of higher air pressure. This is due to the atmosphere being less dense in higher altitudes. The consequence of this is hypoxia, also known as oxygen deprivation. This occurs because the low air pressure makes it hard for oxygen to pass through humans selectively permeable lungs. This results of this start with being easily fatigued in physical activity, lack of appetite, vomiting, headache, distorted vision, fatigue, and difficulty thinking clearly.  Later it can result in severe hemorrhaging of the lungs and an abnormal accumulation of fluid around the brain. It also causes high blood pressure and pulse rate, causing stress to weaker hearts.

22.      Short Term: The short term response is the fatigue from physical activity. The reaction of being tired quickly alerts the person being affected to stop and rest until acclimatization can occur.

Facultative: The body will respond when acclimatization takes place. Acclimatization occurs when stresses such as high or low temperatures and intense ultraviolet radiation occur from sun light, or high altitude. The body will produce additional red blood cells and capillaries in order to carry more oxygen. Another occurrence is that the vascular network of muscles work increases better allowing for the transfer of gasses. These changes revert after a few weeks of remaining in low altitude.

Developmental Adaptation: One adaptation from thousands of years of natural selection is an increase in the production in hemoglobin. Hemoglobin is a gas transporting protein that exists within a red blood cell. It allows for increased amounts of oxygen to be carried in the blood.
 
Cultural Adaptation: One example of a cultural adaptation for high altitude is cabin pressurization in airplanes. In this process air is taken and greatly heated to compact it together, then it is cooled and expanded for the cabin, and effectively creates a high oxygen density in high altitude.

33.     Without understanding how and why environmental issue effect the human body there would be no way to create a solution. When human limitations are tested solutions can be designed. For example cabin pressurization would never have been designed if there was no knowledge of why hypoxia occurred for some and not others at higher altitude. It can be used to identify who is at risk for certain conditions, therefore preserving human life.


44.      To put it simply race has no influence on scientific findings. Race was an American concept that is irrelevant scientifically in any way. Environmental influences are what cause adaptation making it the relevant way to study human variation. Race groups people in way where adaptation patterns are missed because it has no impact on environmental location, which is where adaptation can be noticed.