1. Select only ONE of the following environmental stresses: (a) heat, (b) high levels of solar radiation, (c) cold, or (d) high altitude. Discuss specifically how this environmental stress negatively impacts the survival of humans by disturbing homeostasis.

 High Levels of solar radiation can negatively impact humans by disturbing our homeostasis and altering our ability to survive. When radiation occurs from solar storms in space, these storms produce waves of radiation rays. For example UVA rays are able to penetrate through the epidermis layer of human skin and affect the dermis layer, causing defects in human cells. Other rays such as UVB rays are also produced and strictly affect the epidermis layer of the skin again causing cell deformation and causing skin cancer which is harmful to our stability and balance.  The human body has a negative reaction to high levels of solar radiation.  

2. Identify 4 ways in which humans have adapted to this stress, choosing one specific adaptation from each of the different types of adaptations listed above (short term, facultative, developmental and cultural). Include images of the adaptations.

                Short Term response: When Humans are exposed to high levels of radiation, for example, being at the beach to long exposed to the suns UV rays causing your skin to burn and turn red and feel raw.  This is also a warning reaction that the body produces to warn you of the harmful exposure. Level of melanin that a human produces is also responsible for how much a person can withstand being exposed to these harmful rays such as UVA / UVB before experiencing severe damage the skin cells.

 

Facultative: Have you ever notice that in the summer time humans tend to be a little more on the tan side, and during the winter months people tend to be more pale and white. Well this is because the body is responding to environmental stresses. In the summer months humans tend to be outside more than in the winter, so we expose ourselves to the UV rays produced by the sun. When these rays are absorb in great amounts it causes skin cells to become defective. When the human skin becomes tanner it is producing a sunscreen that will remain until we remove this environmental stress. Tanner skin protects our skin and keeps us from absorbing too much of the UVA/UVB rays that can cause skin cells to become defective.

 

                Developmental:  Developmental changes are found in populations that have been subjected to a large amount of solar radiation there for their skin color has become dark to help shield themselves for an over absorption  of UV rays. An example of this is people who live in the Savannah’s of Africa, they are dark skin and able to withstand higher levels of solar radiation exposure. There is a proven correlation between people’s skin color and living environments.

Cultural:  A cultural adaptation to a harmful UV rays have been examples like wearing clothing that protects you from the environmental stress, we have also developed sunscreen cream that we can use to help protect our skin from UV rays penetrating, and also creating shelters that help us cover ourselves and protect us from harsh exposure to environmental stresses.  Also migration can play a role, by fleeing one site in order to survive during a certain season and then returning back during the prime seasons.

3. What are the benefits of studying human variation from this perspective across environmental clines? Can information from explorations like this be useful to help us in any way? Offer one example of how this information can be used in a productive way.

             The benefits of studying human variation is to understand how humans have adapted and altered to be able to exist and protect themselves from harsh environmental stress imposed by mother nature. We can see how population have migrated or developed traits to endure the environmental stresses.  We can look back and see how humans have evolved throughout the years and adapted.  This information can give us insight about who we are today and why we have developed certain traits.  We can understand how important some of our traits are to our human existence and how populations survived.  By studying skin cancer and UV rays, we can determine what levels are acceptable to the human body and what levels are need to survive in order for the body to produce the proper levels of vitamin D.

4. How would you use race to understand the variation of the adaptations you listed in #2? Explain why the study of environmental influences on adaptations is a better way to understand human variation than by the use of race.

                 I would use race to help determine geographical location of populations so I can analyze the human traits according to the environmental stress they were or are exposed to.  This will also help with understanding their ancestral traits and be able to keep track of when population may have migrated due to harsh environmental stresses.  When studying environmental influences of populations over a long period of time, we start to notice patterns that develop due to the exposure of a not normal environmental condition that cause traits to alter and change in order to adapt to the new environmental conditional. Thus we can see when certain populations have migrated in order to keep alive by finding other geographical locations that then subject themselves to a different kind of environmental stress which causes the body to change and evolve traits to better adapt to the new and less harsh environment.  We can actually acknowledge these changes and verify that certain traits have been developed due to a change in environmental influences.