Variation and Race

1.      High levels of solar radiation is an environmental stressor which negatively impacts the survival of humans by disturbing homeostasis; radiation occurs from solar storms in the universe. This produces UVA rays which penetrate through human skin going through the epidermis layer and causing defects in the human cells.  Then there is the UVB rays that goes through our skin and that cause’s cell deformation, skin cancer, and this genetic level disturbs homeostasis and is harmful to our survival.

2.      Short term adaptation for solar radiation is hard to say since there isn’t really one other than stay out of the sun.

          Facultative adaptation to protect us from the harmful UVB radiation waves is skin tanning and tanning happens when exposure to sunlight triggers a protective mechanism through increased melanin production in the epidermis layer.   The more time spend in the sun during the summer months with the warmer weather, it is common to see people of both fair and dark skin have a darker complexion.

           Developmental is in populations that have been exposed to a large amount of solar radiation and so therefore their skin has become dark to help protect themselves for an over absorption of UV rays.  People who live in the Savannahs of Africa or tropical places have dark skin and are able to withstand higher levels of solar radiation exposure.  You can see the proven correlation between people’s skin color and living environments. 

          Cultural adaptation to the harmful UVA and UVB rays are clothing, shelter, hats, sunscreen lotions and sprays.  Clothing and shelter made it possible to limit exposure to the sun’s radiation and therefore reduced the need for such high levels of melanin production.  Migrating to other environments such as forested areas also reduced our time in the sun and see the change in skin pigmentation with the lighter skinned populations possessing more of the northern geographical regions and darker skinned populations possessing more central and southern regions closest to the equator.  Now people of all skin pigments now populate all regions of the globe and instead of migrate northward if you are light skinned, the invention of sunscreen lotion can protect you for longer periods of time in the sun. 

3.       The benefits of studying human variation is to understand the changes of various sample populations over time, human adaptation and to evaluate and see the environmental stressors.   For example, by studying UV radiation we discovered it causes skin cancer or by studying skin cancer we found that it is caused by UV rays.  Either way we need to determine what levels are acceptable to the human body and what amount is needed to survive in order for the body to produce the proper levels of vitamin D. 

4.      I would use race only to classify geographic groups of people who have the same or similar set of adaptations to the same environment and this will help with understanding their ancestral traits and able to keep track of when population may have migrated due to environmental stresses. Studying the environmental influences of a group of people over long periods of time you see patterns which evolved as adaptations to those outside stressors and some adaptations like being born with lighter or darker skin become permanent, while others will remain until the stressor has been removed such as tanning during the summer with increased sun exposure.  I believe that being able to study the human species is a great tool to help people overcome racism and see more of the ways we are alike than the ways in which we differ and that certain traits have been developed due to a change in the environmental influences.