1. Heat. This environmental stress negatively impacts survival by causing dehydration to the human body. It disrupts homeostasis as too much heat can cause permanent brain damage, and the shutting down of vital body parts. This is why internally humans search for shade when it is too hot outside as to cool down, and why water is so important in hot temperatures. We can see this with areas like Africa and areas that are close to the Earth's equator. In Africa for example the average temperature in a country like Ethiopia is around 93 degrees. And Africa has also seen some of the most extreme records in heat at 136 degrees in Libya. Heat can be seen as the environmental stress into why the African race has slim tall bodies, reducing their surface area in order to escape heat.
 |
| Short Term |
2. A. Short Term: For short term humans have the ability to adapt by releasing sweat or perspiration across ones body in order to cool it down.
 |
| Facultative |
B. Facultative: For facultative, the human body releases melanin to tan the skin. This function is used to protect the skin from harmful UV rays. Melanin makes the skin pigment become darker so its an easy way to see how this is used.
 |
| Developmental |
C. Developmental: Developmentally humans have adapted to heat by the pigment in their skin color. As seen with humans found closer to the equator or places of extreme temperature, these humans are born with a high amount of melanin in their skin already instead of producing it like it is with tanning. We can also see height and slenderness as seen with humans in Africa who are born taller and sleeker in order to reduce their surface area from receiving too much heat.
 |
| Cultural |
D. Cultural: Culturally we have created ways and technological advances to help us cool off. We have air conditioners, special clothing that catches our sweat and distributes it along our body keeping us cool during sport like activities, and have created hats as well in which keep the sun out of face and creates shade as well.
3. Benefits of studying human variation across environmental clines can help us see what genes and phenotypes are useful in these climates compared to climates that are the exact opposite, for example, extreme heat to extreme cold. This information can be used in productive ways by giving us a better understanding of how humans adapt to climates. As well as finding out what is natures way of adapting, therefore, giving us an idea of what to create in order to help us combat the extreme temperatures.
4. We can use race as to see why Africans are better suited to the heat than the human counterpart of one who is European and lives in extreme cold like Russia. For example looking into why their skin pigment is darker because of higher melanin, and why they are sleeker and taller. Environmental influences are a better way to understand human variation than race because race doesn't necessarily give you all the answers as environmental influences do that is because race is more of humans who are grouped up in a region. Meanwhile environmental influences give you concrete evidence by understanding why there are adaptations to these climates, so it explains to you why this specific race is adapting to the specific environmental influence in which they live in.
Hi Abner,
ReplyDeleteI like how you went into detail and got straight to the point on your post. There was a lot of information that you gave, and it was really well put together. I had a different type of topic, but it was almost the same information. But it's cool how heat and solar is similar to high levels of solar radiation. Just one question that I didn't really understand. When you talk about how people that live in the equator have tall slender bodies, but what about people in south or central America that live close to the equator are very short? I don't really think that size has to do with being able to take in high amount of UV rays.
Good detail on your opening section, with just a couple of comments:
ReplyDeleteFirst, note that the dehydration is not *directly* related to heat stress. It is the result of the body trying to adapt to heat stress through sweating, i.e., it is indirectly related.
Second, why can't the body function well at temperatures higher than the optimum 98.6 degrees? What happens to the body that causes the problems you identify?
Yes, sweating is a short term adaptation to heat, but how does it work? There is a reason why it is also called "evaporative cooling".
Melanin production is a response to solar radiation stress, not heat stress. An example of a facultative response to heat stress is vasodilation, which opens the capillaries near the skin and allows for more rapid dissipation of excess heat.
For your developmental trait, why didn't you discuss the "slim tall bodies" you raise in the first paragraph?? That is a developmental trait to heat, as explained by the Bergmann & Allen rules of body shape. Instead, you run into the same problem as your facultative trait, as melanin production is a response to solar radiation stress, not heat stress. Make sure you check the assignment modules to review this information and clear up this misconception.
Good cultural adaptation.
"... giving us an idea of what to create in order to help us combat the extreme temperatures."
Okay... can you be more specific? I agree that knowledge is always useful, but can you identify a way this knowledge can be useful in a concrete way? Can knowledge on adaptations to hot climates have medical implications? Help us develop clothing that releases heat more efficiently? Can we develop new means of home/building construction that might help decrease heat retention? How can we actually use this information in an applied fashion?
For your last section, not that "African" and "European" and "Russian" are not races. They are geographical locations or ethnic groups. And are you actually using race here or just using the adaptive environmental approach and layering race over top of it? Is it really possible to use race to help us 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.
Hey Abner,
ReplyDeleteI think you did a great job at explaining how the body adapts to heat. I did the same topic so I definitely see similarities in our posts and liked that I could learn more off of yours as well. You had some great pictures to go along with it and I agree with you on why you believe it's better to study the environment adaptations rather than race. Great job!