Week 5 Human variation and race
1.) An environmental stress that negatively impacts the survival of humans by disturbing homeostasis is heat. Heat stroke, which raises your body temperature to 104 degrees, is caused by physical activity in high temperatures for a long period of time. Heat can also cause heat rashes and heat exhaustion. Heat rashes are caused by clogged sweat glands from too much sweating. While Heat exhaustion occurs when you have been exposed to heat for too long and are suffering from dehydration.
2.)
Short term: One way that humans have adapted to the environmental stress of heat is by sweating. Sweating occurs when your body temperature rises due to high temperatures or physical activity. The sweat evaporates from the skin's surface which removes excess heat from the body and allows the body to cool down.
Facultative: A facultative way the body has adapted to heat stress is vasodilation. In this process, blood is brought to the surface of the skin which then lets the heat exit the body.
Developmental: Body structure is a developmental adaptation to heat. Taller body types are able to cool a lot faster than shorter body types because of the amount of surface area the taller body has.
Cultural: A way humans have adapted to heat stress culturally is by technology such as fans and air conditioning. Fans allow people to travel with a portable device that cools them down in extreme heat.
3.) The benefits of studying human variation is being able to get a better insight on how the human body adapts to different environments. Information like this can be useful in order to show us things that we can change to improve our way of living in different environments. Clothing is an example of an adaption that we have control over and would be useful because different types of clothing can protect us from the different types of harmful weather.
4.) Race is not able to explain the similarities and differences of people, it is the changes that the environment has on others and the display of their different ways of adapting that shows human variation. Each person looks and lives differently but their way of adapting is not based off the way they look, it is based off their ability to adapt to different types of environments.
I learned two things from your blog, 1) I did not know heat rash was caused by clogged sweat glands, 2) Taller body types are able to cool faster than short. very informative. I also agree with you that race does not explain the similarities or differences of people but the environment does.
ReplyDeleteOkay on your opening section, with a couple of comments. Heat stroke doesn't require exercise for this to happen. Hyperthermia (too much body heat) can occur just by staying too long in a hot environment with no relief. As the body temperature rises, the body starts to sweat heavily and the heart rate rises. This defines "heat exhaustion". When the sweating stop, that's a bad sign, as it indicates that the body is developing heat stroke, with temperatures rising above 104 degrees.:
ReplyDeleteAdditionally, while you've identified some of the final results that can arise from heat stress, can you explain why they happen? Why can't the human body function correctly above that optimum level of 98.6 degrees? What happens to the body's organs and circulatory system above that point? Think a little deeper on this issue to explain why it is so important for the body to adapt to heat stress.
Good discussion on all four types of adaptations. The only correction is that the developmental adaptation isn't just about height. It's about shape. The long lean body shape (even if you are only 4 feet tall) helps to release excess heat better from the body than if you have a round body shape (even if you are 6 feet tall). This is explained by Bergmann's and Allen's rule, covered in the resources in the assignment module.
With regard to the benefits section, I follow your explanation, but that would only apply to the cultural adaptation, correct? I mean, can understanding how your body responds to heat stress by sweating, vasodilating and being longer and leaner help you sweat better, vasodilate better and grow longer and leaner? We have no say on that, so knowledge doesn't have a direct affect there. But can we use this information in other ways? Can understanding how the body responds to heat stress have medical implications? Can it help us make clothing and build homes that help release excess heat and keep us cooler? How can we actually apply this information?
I agree with your conclusion in the last section and you made a good attempt to explain why. Race is an issue we face on a daily basis, but often this is the first time students actually have to set back and think about what race actually *is*, and that is necessary to answer this question. 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.
Nice job on this! I was kinda surprised at the part about how tall bodies are able to cool down faster. I always though everyone had a different reaction to the heat, regardless of height and size. Nice job overall though.
ReplyDelete