Lala Land

 

Human Variation and Race

1.       High levels of solar radiation negatively impact the survival of humans by disturbing homeostasis. This can occur with either too much exposure to the sun or too little. Our body needs Vitamin D from the sun in order to function properly. Without Vitamin D our body can experience weakness in our immunity, bones, teeth, and muscles. Solar radiation provides our body with the Vitamin D that we need to strengthen our body in all those areas. It helps restore bone tissue and replaces the old bone with new bone. Also too much solar radiation can have a negative impact because the overexposure of UV rays can be absorbed into the cells and turn into skin cancer. It seems were doomed with it or without it. Solar radiation needs to be absorbed in moderation to receive the full benefits; overexposure can lead to a disruption in homeostasis and can turn into a very dangerous thing if not monitored.

   2.       Cultural Adaption: One form of a cultural adaption that humans have used to adapt to this stress is by using sunscreen. Just because you wear sunscreen when out in the sun doesn’t mean your completely safe from its harm. It does help reduce the amount of UV rays that get absorbed into your skin, but there are some that can still seep through so it is best to use other forms of adaptions such as putting an umbrella up at the beach or putting on a t-shirt if directly exposed to the sun.

 

Facultative Adaption: Since UV rays are the strongest in the summer vs. the winter most people like to lay out and tan by the pool. Even during the winter individuals will go to the tanning salons and use that as a source to maintain their summer body glow. This is an example of Facultative Adaption. Melanin increases in size and number when exposed to ultra violet radiation. This is an example of altering a phenotypic expression in response to an environmental stress. Now some people aren’t as lucky, like me most fair skinned people have a hard time tanning so not only are we altering our phenotypic expressions it can be more painful and harmful than for most. We are more likely to burn and peel and be at risk for skin cancer.

 

 
 

 

Developmental Adaption: Individuals who are exposed to the sun for longer periods of time are at a higher risk of developing skin cancer ( melanoma).  The UV rays lead to an increased production of melanin. These individuals over time will develop a darker skin tone and are more likely to develop skin cancer. Not only does over exposer of solar radiation cause developmental adaption but so does being underexposed to UV Rays. People who live in northern latitudes where there is less solar radiation are better off at protecting their skin, but for those with darker skin this becomes a serious risk. Reduced solar radiation leads to a lack of Vitamin D which can lead to life threatening conditions such as rickets disease or osteoporosis. This can have a lasting effect, for instance women who had low levels of Vitamin D for long amounts of time are at risk of having a normal delivery due to the deformities of the pelvic. It is interesting because research shows that is common for dark skinned people to be Vitamin D deficient because of lacking melanin to protect their skin, but even for myself, as white as you can get am severely Vitamin D deficient, I take 2,000 mg. I notice without it my bones hurt and crack a lot and I constantly feel tired. It just goes to show how important it really is!

 

Short Term: I don’t know If we have a short term adaption to solar radiation. With too much sun we can either increase our risk of cancer because of burning and overexposure to UV Rays, or with under exposure we lack Vitamin D which provides our body with what it needs and without it can lead to permanent life altering conditions such as heart disease or bone diseases.

   3.       I think it is important to study the benefits of human variation from this perspective because information from these explorations can help us in finding new ways to defend ourselves against the negative impacts of solar radiation or help us benefit from getting more of the sun. It is helpful to study environments where people don’t receive as much sun because we can study the effects the lack of Vitamin D and Melanin can have on them, such as bone diseases or affecting the way they have children. We are able to understand better how we can help those who need more Vitamin D.  It is also beneficial to study those environments where the sun is extremely powerful so we can see how the intake of too much Vitamin D can lead to life threatening conditions such as cancer. Looking at these different environments allows us to learn to intake the sun in a healthy way.

4.       By using race to better understand the variation of adaptions of solar radiation, we are able to discover how specific environments are better suited for the exposure of the sun, and which environments are not. I think the study of environmental influences on adaptions is a better way to understand human variation than by the use of race because we have a better understanding of how people adapted to their own environments. For example I think sometimes people might have the misconception that races with darker skin probably get the most Vitamin D because they get a lot of sun, when in at times where their environment is lacking solar radiation they develop a  higher risk of being deficient not because of their skin color but because of their environment. I know for me this was an eye opener in becoming more understanding of how our environment affects us in a great way.