Tuesday, March 26, 2013

Variation and Adaptation


11)   Heat is an environmental stress that negatively affects homoeostasis because it causes hyperthermia within our bodies. Life threatening hyperthermia typically starts in humans when their temperatures rise to 105-107° F.  Only a few days at this high temperature level is likely to result in the deterioration of internal organs and death.

22)   A short-term adaptation for heat is sweating.  This allows our body to use our sweat to evaporate, cooling off the spot exposed to the sweat,

A facultative adaptation for heat is the urine volume decrease, the blood vessels dilating, and salt in sweat decreasing.  The urine volume decrease and the salt in sweat decrease help prevent dehydration.  The dilation allows access materials in our body to be let out.

A developmental adapting would be the body mass of someone to the smaller than that of someone from a cold area.  The body mass allows those in a hot area to radiate heat out of their body.

A culture adaptation is the type of clothes we wear daily in a hot area.  The ability to wear tank tops and shorts allow the heat within our bodies to be let out easier than if we were wearing thicker close.

33)   The benefits are that we better know how to adjust to a certain areas around the world when a season of the year is coming around.  A way that knowing how to adjust to heat is beneficial is that if someone wanted to go to a hot area, say near the equator of the world, that person would know not to wear thick clothing and to bring water to avoid dehydration from hyperthermia.

44)   Race can help understand the adaptation that I listed in number two by studying those near hot areas like Africa and tropical places.  By studying those in hot areas you can truly find out if sweating, dilatation of skin, body mass, and clothes really do affect the effects from the heat.
Environmental study is better than race study because a race could possess certain traits that an environmental study won’t show.  For example, darker skin people are migrating to place that are cold because they found a way to keep their bodies warm.  This proves that you don’t have to have lighter skin to live in a cold area.  Something that only a race study will show as an outcome.  Environmentally, taking an “x” amount of people and studying them in different places will show naturally how the body reacts in certain places.

4 comments:

  1. Very good opening discussion on heat stress.

    Images?

    Good work on the short term, developmental and cultural adaptations.

    You are correct that vasodilation is a facultative adaptation to heat stress. How does decreasing the salt in sweat help address heat stress? Keep in mind that facultative adaptations may need to continue over an extended period of time and therefore need to be beneficial. Decreased urine contact can be harmful to the body and is usually a last resort by the body to retain needed water. It is a warning sign that you are dehydrated, not a good adaptation that you want to see. There are species of animals that have developed (genetically) very concentrated urine, usually desert creatures, but this is a long-term, developmental trait, not a facultative one.

    Okay on section #3.

    Your description in section #4 is just the adaptive approach. It doesn't use race in any meaningful productive way. You were supposed to have difficulty finding a useful way to use race to study human variation! The question is why? Race is a social construct, not a biological one. It is subject to cultural bias and we can't use it as an objective basis for understanding biology since it isn't based in biology.

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  2. Dear Justin,

    I also chose heat as my environmental stress. It was interesting to read how hyperthermia negatively affects homeostasis. I explained in my post that homeostasis is disturbed by means of water and sodium loss. We had pretty much the same answers for adaptations, except for the facultative. I had no idea that heat could affect one's urine. Overall great post! You have some excellent detailed information and it is obvious that you worked hard on this. Although I think you forgot to add images.

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  3. Hi Justin!

    I thought your post was good! I also did heat for my discussion blog. Like Sean said I also thought it was interesting how you touched on Hypothermia from heat. I remember reading an article on that but I didn't talk much about in my post. Before this assignment, I was always under the impression that Hypothermia was only caused from cold weather. I guess you learn something new everyday! I didn't really understand that last section of the assignment for my own post but I liked reading yours! Even though it didn't touch on the point of the topic as much as you would have liked, it was a good thought process and it helped me understand it better than I did before. Thanks and good job!

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  4. I found your post to be very informative. I had no idea that hyperthermia resulted in the deterioration of your internal organs. I also thought you did a great job describing the different adaptations. Overall good job.

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