Tuesday, June 3, 2014

Human Variation & Race Blog




Cold is an environmental stress that negatively impacts the survival of humans by disturbing homeostasis.  Our normal body temperature is 98.6 degrees when we expose our bodies to the cold our body tries to regulate the temperature and begins triggering our muscles to shiver.  Our muscles shivering allows heat to be generated but at the same time our body starts pumping more blood to our organs to counteract the cold temperature.  Our extremities like fingers lack blood and become ice cold. If this happens for too long cells start dying and in a worst case scenario that part of the body is lost to frost bite. 

Short-term:  When are muscles start shivering is a short term response to our bodies being cold and by shivering the constant muscle constrictions create more energy which turns into heat.

Facultative Adaptation:  A Facultative Adaptation Response we use in response to cold is vaso-constriction.  In Vasoconstriction the diameter of the capillaries is reduced and blood flow is constricted.  It allows our bodies to stay warmer and fight the cold.

Developmental Adaptation:  A developmental adaptation response to cold is seen in our body shape and size.  People in cold environments have round bodies and the fat is usually in areas where vital organs are kept safe from the cold. 


Cultural Adaptation:  A Cultural Adaptation response is clothing.  In colder cultures they tend to use thicker clothing for example fur jackets and headwear are used to protect our bodies from the cold.  Another example is pressurizing airplane cabins with oxygen because not only the height but cold temperature would interfere with our breathing. 

Benefits in Studying Human Variation:  Examining different cultures and body types and how they adapt to the cold will help facilitate scientist in the understanding of when certain events are triggered such as shivering and vasoconstriction.  And to explore the different temperatures in different body sizes that trigger such events. The main benefit lies in science because the exploration of human variation can lead to a more thorough knowledge in our bodies.

I believe race isn’t a good way to describe human variation.  Environmental influences to adaptation is a better way because it should be based off individuals not races.  For example dark skin has to do with sun adaption rather than race.

5 comments:

  1. Hello Jeanette,
    I also did my blog post on cold and agree about your comment on environmental adaptation and race. I do believe that human variation is based on their adaptation versus their ethnicity. Overall I enjoyed how straight forward you were with your information and great job! Was a pleasure blogging with you1 Enjoy your summer!

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  2. great post and photos! I often see very small/skinny people wearing sweaters in 90 degree weather and although it looks crazy I guess they get cold easier due to lack of insulation.

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  3. Okay on your description of the negative affects of cold stress, but at worse, cold stress can shut down your internal organs and result in death.

    Good discussion on all four adaptations. One clarification: Vasoconstriction is used as a short term adaptation. For longer term, factultative traits, the body resorts to alternating vasoconstriction/vasodilation, which still retains most heat in the body core but allows some blood to reach the extremities in an attempt to reduce tissue death.

    Good discussion on the benefits of the adaptive approach.

    Can we take the issue of race as step further, beyond whether it is a "good" way to study human variation? Is it even possible to understand variation using race? Race is a social construct, subject to cultural bias. Given that, is is possible to use it to understand a purely biological trait? Does race cause adaptations? Or can you only say that about the environment?

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    1. I apologize but I haven't been able to log on to my canyons email nor bb9 I've tried since 9 pm when I went on lunch just to take the final I just got off work and still I tried and it gives me server error messages. I emailed bb9 support but they haven't replied I did it from my personal email I do not remember your email address so can you please reply at jeannettelara11@gmail.com. I will be awake waiting for your reply can you make the final accessible outside of bb9? I normally get off work at 1030/11 but my boss allowed me to take a break just for the final at 9 and I still had issues. Please reply I know it's late again I apologize.

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  4. Jeanette,
    I too found it interesting that there are different body types that deal with the cold better than others. People who have to deal with the cold all the time have more body fat and their bodies actually produce more body heat. I also had no idea that before hypothermia the veins contract and get smaller so that less body heat is used to try and save as much as possible.

    Erica

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