Sunday, January 31, 2016

Human Variation and Race



Human Variation and Race Blog

            The environmental stress I choose that negatively impacts the survival of humans by disturbing homeostasis is living in the high altitude areas, particularly above 10,000 feet. According to the textbook, “today as many as 25 million people live at altitudes above 10,000 feet”. At altitudes of this nature, there are many reasons that this sort of elevation can produce stress on the body. Some examples of the stresses are hypoxia, more powerful solar radiation, colder temperatures, and nutritionally challenged food because of the territory. Hypoxia seems to be the biggest problem these people face that live high above sea level. It is caused by lowered barometric pressure, it is not there is reduced oxygen, it’s less potent. The body has to make adjustments to be able to use the oxygen provided. The part of the way the body adapts that was interesting to me was how the body processes glucose, which is important for the brain and heart. People that live in this high altitude regions burn glucose in a way that allows more effective oxygen consumption. The body knows what we need and changes to provide that for the individual contingent on the geographical. Amazing bodies we have.
            Short term: Somebody who travels from lower to higher altitudes need a day or two to acclimate to their surroundings. In that short time a few changes will happen for the individual, such as; increase in metabolic rate, breathing, and rate of the heart.          Facultative: The production of the red blood cells increases to carry the oxygen to body parts and tissue. It is amazing how the red blood cells have the hemoglobin, the protein accountable for moving oxygen around the body.
            Developmental: People of high altitude grow at a slower rate and tend to be shorter in size. They have greater lung and heart capacity. There is less oxygen at higher elevations and this is effecting infants in brain development and mortality.
            Cultural: High-altitude variation in humans is prevalent the populations in Tibet, the Andes and Ethiopia, who have developed the capacity to endure at elevation. These residents succeed well in the highness. These people have endured massive physical and genetic alterations, chiefly in the areas of respiration and blood flow.
            The benefits of studying human variation from this perspective can help one when traveling to higher elevations. If I was running a marathon, I would check if it was a flat run or hills and elevation. I tend to favor the Huntington Beach one because it is flat. It is already hard work why make it harder.
            I believe the study of environmental influences on adaption is a better way to understand the human variation than the use of race. The study of environmental influences on adaption is a better way to understand human variation because the environment effects all people differently.  The world we live in and the physique is constantly evolving.   I don’t see how race is a reason with how humans acclimate to their environment.


8 comments:

  1. This comment has been removed by the author.

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  2. Very good discussion on the dangers of high altitude stress, correctly focusing on hypoxia (as the others are due to other stresses, not high altitude).

    Good thorough explanation of short term and facultative traits.

    For your developmental traits, you correctly explain how populations at high altitudes tend to have a larger lung capacity and a more massive heart muscle. Remember that adaptive traits need to help an organism deal with the stress in question, so how does shorter stature and slowed growth rates help with high altitude stress? Or is that just a result of reduced access to oxygen? For populations living long term in high altitudes, you don't see as much impact on infants but I'm glad you raised the issue of reproduction. What are the dangers to a pregnant woman moving from low to high altitude? Many of the dangers high altitude imposes on reproduction come during pregnancy when the oxygen must move across the maternal/placental barrier. Worth checking into.

    Cultural is unique in this post because it is the one trait that has nothing to do with genetics or biology. You seem to still be taking about biological adaptations. What tools or practices have humans developed to help deal with hypoxia?

    I agree that understanding the issues of hypoxia can be an advantage when traveling, but the question can be taken beyond the trait you chose. Can the information gained from using the adaptive approach have medical implications? Can we use the information to produce inventions that help us adapt to different environments?

    "I don’t see how race is a reason with how humans acclimate to their environment."

    You are closest to the point of this question with this last line. Think about the differences between race and the adaptive/environmental approach. The environment actually has a causal relationship with the adaptations in question. That is why we can use the environment to help us understand *why* humans vary as we do. Can you do the same thing with race? Does race have a causal relationship with our adaptive traits? In short, no. Race is a social construct, created by humans to organized and classify the human species. It is subjective and different cultures have different systems of race according to their cultural bias. So if it is subjective and biased and doesn't cause biological adaptations, how can we use it to understand why humans vary as we do?

    Good images.

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  3. I agree that culture has nothing to do with biological adaptation but race is/has become a definition of it in regards to the differences being discussed. Its perfectly okay to use different races as an example of biological change in regards to environment.

    Celeste

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    Replies
    1. I.e. Africans have black skin due the climate, environmental. Nordic adapted to.cold climate with developing lighter blue eyrs and skin. These are not cultural changes BUT the are biological changes and define races
      Celeste

      Delete
    2. I.e. Africans have black skin due the climate, environmental. Nordic adapted to.cold climate with developing lighter blue eyrs and skin. These are not cultural changes BUT the are biological changes and define races
      Celeste

      Delete
  4. I agree that culture has nothing to do with biological adaptation but race is/has become a definition of it in regards to the differences being discussed. Its perfectly okay to use different races as an example of biological change in regards to environment.

    Celeste

    ReplyDelete
  5. The use of "race" as an example of biological traits is in context of the piece. I.e. African race black skin is due to climate i.e. nordic blue eyes and light skin is also due to climate.
    Celeste

    ReplyDelete
  6. The use of "race" as an example of biological traits is in context of the piece. I.e. African race black skin is due to climate i.e. nordic blue eyes and light skin is also due to climate.
    Celeste

    ReplyDelete