1. Heat impacts human’s homeostasis by impeding the bodies ability to function normally.Elevated temperatures cause skin cells to burn and muscles to function abnormally. Heat also causes water loss which causes dehydration.
2. Short Term: Sweating in response to heat stress.
Developmental: Long, extended frames and extremities in humans.
Facultative: Fainting
Cultural: Air conditioning
3. It allows for scientists to segregate different gradual evolutionary forces from one another. Allowing for easier tracing and studying.
4. Different races of people have different adaptations to their respective native environments. Dark skin for warmer climates being an example of this. Today the color of skin does not dictate the environment you are from, therefore race is a poor indicator of variation in terms of adaptation.
Andrew, I enjoyed reading your post. Learning about the stress heat can cause on our bodies is a very interesting topic, as I have learned way more about it now then before. I too race is a bad way to look at people, as we should better understand people based of the environment and culture that surrounds them.
ReplyDeleteHeat stress impacts the body at a more basic level than sun burn, muscle malfunction and dehydration. Our body is designed to function best at 98.6 degrees F. When it rises above this, our body starts to have problems functioning due to this "hypoerthermia". If the core body temperature rises too high, cells begin to break down and you have organ malfunction. This is the start of "heat stroke", which if left untreated will eventually lead to death. This is what we need to know to understand why heat stress is so dangerous to humans' homeostasis.
ReplyDeleteYes, sweating is a short term response to heat stress, but how does it help to cool the body? Why is it called "evaporative cooling"?
For your facultative response, remember that adaptations are changes in the body that help the body adapt to a stress. Fainting is an indicator that the body is NOT adapting to heat stress. It isn't an adaptation itself. A facultative adaptation to heat stress is vasodilation, which is the expansion of capillaries under the skin to help the dissipation of heat from the blood stream through the skin to the outer air.
How do long bodies and limbs help with heat stress? I agree that this is an adaptive response to heat, but this needed to be explained. Check out Bergmann's and Allen's rules in this week's module.
Yes, air conditioning is considered a cultural adaptation, though perhaps an explanation could have been provided?
" It allows for scientists to segregate different gradual evolutionary forces from one another."
I'm afraid I don't understand what that means. We are looking at human variation from an adaptive approach and gaining understanding as to how and why our bodies respond under different types of stresses. How can this information be used in a practical way? Can knowledge on adaptations to hot climates have medical implications? Help us develop clothing that release 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?
First, it is important to recognize that race is not solely determined by skin color. Other traits, like facial features and body shape, can come into play as well.
You say that race doesn't dictate which environment you are from. That is true, but what we are asking here is if race "dictates" (or impacts or shapes) our physical adaptations, not our environment. We are asking if race can explain our traits, and in order to do that, there needs to be a causal relationship between the basis for the explanation (i.e., race) and the thing you are trying to explain (i.e., adaptations). We see that relationship between the environment and human variation. The adaptive approach demonstrates that the environment causes our adaptations. Do we see that with race as well?
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.