1) High levels of solar radiation and its effects on human homeostasis.
Depending on the origin of a person, solar radiation can have some serious negative impacts on them. If they originated from near the north pole and suddenly were moved to central Africa, they would not be able to handle the intense solar radiation and probably get severe skin burns and possible epidermic cancer as a result. They wouldn't have nearly as much melanin as someone who is from there.
2) Adaptations: Solar radiation
Short-term adaptation: In people who have less melanin, it is common to see sunburns on the skin (or even worse, sun bleaching). Exposure to UVA and UVB rays cause sunburn if not properly protected or if you have very low melanin in your skin.
Facultative adaptation: In some instances, humans have adapted to tan, allowing for slightly more protection from the sun.
Developmental adaptations: Populations located closer to the equator generally have darker skin. They are exposed to the sun's rays for far longer than people who live farther north and as a result have developed more melanin.
Cultural adaptations: Humans culturally have adapted to protect themselves through a numerous amount of ways. Clothing, large hats and sunscreen are all great examples of man-made items that protect the skin from the harsh radiation of the sun.
3) Some benefits that can come out of studying a population in any given environmental cline is that we see how the world and nature affects them, and how they naturally adapt and change to survive the given cline over generations. These can lead to breakthroughs in technology and medicine by studying how different environments change us. For example, watching the changes of a sudden migration of one population to another location could help us better understand how these environments affect us, and prepare us for different clothing, cosmetics and medicines based on these findings.
4) I would use race to understand the variations listed in question 2 by explaining the geographic location commonly associated with a race. Different races are more common from different areas and we can study how these changes came to be by looking at where geographically they originated from. An example would be someone who was Caucasian versus someone who was African-American, you would know someone could have originated from a place closer to the equator by looking at their melanin levels evidently exhibited on their skin.
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ReplyDeleteThe opening discussion was designed to explain the general danger of solar radiation to human homeostasis, not to break down the differences in how this is handled in the human population via the adaptations. That comes later. The key issue is the harm caused by the UV radiation and should have been the focus here, but additionally, do we receive any benefits from the sun? What about Vitamin D absorption, the "sunshine vitamin"? Might this create a situation where our adaptations must meet both needs?
For your short term adaptations, remember that adaptations must help the organism, not hurt them. Sun burns are not good for a human. They are harmful and indicate that damage has already occurred due to solar radiation damage. It is an indicator that the body has not adapted, not that it is adapting. Unfortunately, humans have no short term adaptations to solar radiation. That's one of the reasons why this is such a dangerous stress.
A little more explanation needed for your facultative section. How does tanning work?
For your developmental trait, why do people tend to have lighter skin tones? Why not just retain the dark skin color to protect against any future possiblel UV radiation exposure? How does Vitamin D exposure help explain this?
Good cultural section.
Good discussion on the practical applications of this type of research.
In your last section, you are just layering on race over top of the adaptive approach. You aren't actually using race to understand our adaptations. Recognize that it is necessary to ask yourself if you actually CAN use race to understand human variation.
To answer this question, you first need to explore what race actually is. Race is not based in biology but is a social construct, based in beliefs and preconceptions, and used only to categorize humans into groups based upon external physical features, much like organizing a box of crayons by color. Race does not *cause* adaptations like environmental stress do, and without that causal relationship, you can't use race to explain adaptations. Race has no explanatory value over human variation.
Hello Emily,
ReplyDeleteNice post, it's pretty important to understand how humans adapt to certain environments and how long that adaptations will last for. Once we understand this we can go further and make new technology to better ourselves for survival. When thinking about just race its hard to understand why certain races are darker or lighter than others, however if we look at the adaptation that each race goes through it makes more sense. The hotter it is the more melanin a person has and the more melanin they have the darker they are; same goes with less melanin the lighter the race is.
Hi Emily,
ReplyDeleteI did not choose solar radiation as my stressor, but your post was very enlightening. I agree that if someone is taken away from what they are accustom to their body can go through a period of shock. In this case, skin would be burnt to a crisp because of the lack of melanin to help protect from harsh rays of the sun.
Even through we did not choose the same topics, we both agree about race and how you can use geographical locations of certain groups. I think it's important to know that a population may exhibit characteristics because of their habitat. If someone lives near the equator where sun is prominent, they will most likely have a high production of keratin making their skin darker.
Thanks for sharing!
Hello, I enjoyed your explanation of solar radiation. Helped me understand the concept better. Its important to know how humans as time goes by able to adapt to environments. It is thanks to the understanding of these factors like solar radiation and how solar radiation can affect people from colder climates that go to hotter climates.
ReplyDeleteHello Emily, I enjoyed reading about solar radiation.
ReplyDeleteI found this topic incredibly complicated and I was unable to choose it for myself because i had a hard time understanding it, But thank you for furthering my knowledge about it It was very useful to me and I agree with your opinions.