SHORT TERM
The environmental stress, heat can have a short term affect by feeling hot all over and sweating when one feels hot. It tells us our body is over heated and reacts by sweating. We can sweat from being in the sun or exercising, just to name a few ways. When we do not sweat, our body is saying we are not hot. When air temperature, one can feel uncomfortable and try anything to make the feeling of being "hot", go away. When under heat, like the sun or even when exercising, we tend to feel weak, because our body is not used to this kind of high body temperature.
FACULTATIVE
One example of facultative adaptation is vasodilation. It opens the capillaries and then becomes closer to the skin. Basically the blood vessels get bigger. When you work out a lot, you are more prone to getting big mussels but veins pop out and its saying your body is in overdrive and sweat a lot and your are extremely hot.
DEVELOPMENTAL
A developmental adaptation to the heat is an example that skinnier people are prone to the heat and usually live in areas where there is heat, where as a large sized person is better off in the cold, due to the body mass of the larger person. This can be evidence from Bergmann's Rule.
CULTURAL
A cultural adaptation to heat can be clothes. When it is hot outside, most people tend to wear shorts and a loose t-shirt or tank shirt with sandals. We do not want to be covered up with jackets otherwise we are even hotter, so we tend to like to wear loose and comfortable short clothes so we do not feel as hot when we wear jeans or jackets. We even wear hats. When the temperature is usually over 80 or 90 degrees we rather wear clothing that shows more skin, so a small breeze can come through and we are less hot, that is why people wear bathing suits in the beach, so they can swim and be comfortable in more open clothes.
Some benefits of studying human variation through environmental stresses can teach us to not judge someone by the way they look, they can be a certain way because of the environment. Racism can be prevented if we seek to judge based on their character not on appearances. We also get the chance to prevent racism but learning some reasons why people are different. We can use this information to teach younger generations why people are the way they are and see how people before us dealt with the stresses from the environment. This information is very good because we can always look back at this and understand the differential variation.
To understand race through heat, we can make an assumption that the color of your skin can be determined by how much sunlight you get, saying the darker skin color you are, the more you are outside under the heat of the sun. That can be a reason on race and their skin tone, i do not agree with that. I believe a person is a certain race because of where they were from and what was around them that made them who they are. To better understand the human variation we can learn about where they came from and the culture they were put in with their surroundings and what they did to survive. The adaptations can show how one must have lived through, like we do now and know we share the same things as our ancestors. We can even stop racism, by showing people what people went through.
Hi Amanda. I really enjoyed reading your post. To tell you the truth, all this talk about heat and high temperatures and sweating made me feel like I was burning up. ;) I thought you had a lot of great information in your post and you really gave good examples to back your points. In regards to race, I agree with you that race is not a contributor to the human variation. For example, people from Africa are dark, but people from South Africa tend to not be dark. Therefor as you stated, I believe that it is more about where you are from geographically rather than what race you are.
ReplyDeleteGreat post. In regards to Bergmann's Rule a shorter person with a higher amount of body fat is more suited for cold conditions because their body is compact and it allows them to retain heat well. A tall, thinner person is more suited for the heat because more of their body is exposed with them being taller which allows more perspiration, and their is less fat to keep them warm. I agree with you that racism can be prevented if we learn the reasons why people are different. Human variation and race is a result of different groups of people living in different environments over the course of many generations. These people took on characteristics that made them more well-suited for the environment they were located in. We are all apart of the same species yet we only have physical differences in appearance. I believe that teaching "race" from an evolutionary perspective can greatly reduce racism.
ReplyDeleteYou jump around a bit in your opening paragraph to race and other topics. All you needed to explain was the biology behind heat stress and how it negatively impacts homeostasis. Why do humans need their bodies at that optimum temperature of 98.6? What happens when it rises from that temperature?
ReplyDeleteSweating itself is the short term adaptation, and this can happen even if we don't actually sense that we are hot. In fact, sweating may be our first indicator that our bodies are experiencing heat stress. How does sweating work? Is it the sweat itself that helps or the evaporation of the sweat?
Vasodilation does happen when you exercise but it can also just happen when you are out in the sun too long. How does vasodilation help to maintain that optimal temperature? How does it help to release heat?
Good identification of Bergmann's rule for your developmental trait. It isn't size per se but the relationship between surface area and body mass. Populations in hot climates tend to have more surface area compared to body mass to help dissipate excess heat more easily through the skin. Populations in cold climate have less surface area for their body mass, to retain heat in the body.
Good discussion on cultural adaptations.
While I agree that reducing racism can be a benefit of the adaptive approach, what are some more practical benefits? Can we use what we learn about why people sweat to design better clothes for hot weather or for exercise? Can the medical community benefit from understanding the process behind vasodilation and Bergmann's rule?
"To understand race through heat, we can make an assumption that the color of your skin can be determined by how much sunlight you get, saying the darker skin color you are, the more you are outside under the heat of the sun."
Most of that sentences is absolutely true, but that doesn't help us use race to understand heat stress. That just uses the adaptive approach and then slaps race onto the final result. Race has no causal relationship with our biological adaptations. The environmental stresses cause our biological traits... race doesn't. It just describes or categorizes them. Without a causal relationship, you can not use race to help us understand why humans vary from population to population.