Human Variation & Race
Cold weather is an environmental stress that negatively impacts the survival of humans by disturbing homeostasis. Homeostasis is the process our bodies undergo to maintain a stable internal environment despite outside environmental factors. When someone is subjected to cold weather, they may notice their skin getting goosebumps or their jaw quivering a bit. These are natural responses to the cold and are actually the result of homeostasis at work, attempting to warm up the cold person. Because cold weather disturbs homeostasis however, it actually impacts the survival of humans. I mean think about it: our normal body temperatures are supposed to stay somewhere in the range of 95ºF-107ºF with the ends of that spectrum signaling something is seriously wrong with a person. When someone gets cold, blood flow to their skin decreases and the body begins sending signals for certain warming activities like shivering and goosebumps. Staying cold for too long is obviously not good for us because of that lack of blood flow. So, that being said, we can see how something like cold weather negatively impacts a humans chance of survival.
From our readings for this week, we know there are four major types of adaptations that may take place in response to an environmental stress such as cold weather. A short-term adaptation is one that does not happen on a genetic level but is a temporary response that allows an organism to quickly restore homeostasis. An example of this adaptation in regards to the cold would be when your skin gets goosebumps when you are standing in 40ºF weather. Another type of adaptation is a facultative adaptation. A facultative adaptation does occur on a genetic level and involves the turning on and off of genes in response to an environmental stress. An example of this in regards to the cold would be the restriction of blood vessels to decrease blood flow to the limbs and increase internal body heat. A developmental adaptation is changes in the DNA of a population in response to a long-term stress. In this case, if a population lives in extremely cold weather, you may notice that the generations of people tend to weigh more and have more body fat. This is a developmental adaptation of the population in response to the cold weather they live in. A final type of adaptation is a cultural adaptation. A cultural adaptation is the use of culture to address an environmental stress. An example of a cultural adaptation to cold would be the use of a jacket or additional clothing to warm your body up.
The benefit of studying human variation from the perspective of this environmental stress is the ability to analyze how different populations of humans respond to the same stress. When looking at the different adaptations made to the cold, we are able to see how different cultures and groups of people manage to address a cold climate in their own way. Here in California, we see plenty of blue skies and sunny days. Our approach to dealing with the cold is putting on an extra sweater or maybe turning the heat up in our car a bit. For others in places like Michigan though, the cold is very much a big part of their lives. Everything from how they dress to how they travel is effected by the weather they are exposed to. Knowing and recognizing this fact allows us to address the needs of all different kinds of humans. For example, clothing companies may sell various types of jackets to meet the different needs of the people buying them.
To be honest, I don’t see how race would help anyone better understand the variation of adaptations in regards to cold weather. Different people respond to cold weather differently but that has more to do with cultural influences and personal preference than it does the color of someone’s skin. The study of environmental influences on adaptations is certainly a better way to understand human variation because it allows us to explore all of the possible responses to a specific stress. It doesn’t limit our research to a specific race or ethnic group, but allows us to compare results across multiple regions and cultures.
Hi Katelyn, I like how you layed out your assignment. It is clear and shows all the questions that were asked clearly. Overall, I belive you had a strong understandign of this assignment and did a very good job. The only thing I would ask is to make your font a little bit bigger, it was hard to read because it was so small. Great job!
ReplyDeleteHi Katelyn, Thank you for the input! I actually have tried several times to change the font bigger and for some reason it isn't letting me :( Sorry it was hard to read!
DeleteHi, I think that you wrote your post very well and I was able to clearly understand your information and the points you were making. I really enjoyed the pictures you added, it created a way to better understand and visually understand the information you were putting out. The one thing I would suggest is that you make your font bigger, it was difficult to read. Overall the information was written great.
ReplyDeleteThank you Ayla! I did try enlarging the font quite a few times but for some reason, it isn't working. I apologize for it being so difficult to read! :(
DeleteHey Kately,
ReplyDeleteI enjoyed reading your post. Your take on cold weather as a disruptor was very interesting. When discussing race, it sort of fits within point 3. The idea is to look at the distinct characteristics of a race and compare that against their background to see how distinct features have developed as a way of protecting homeostasis. It can be difficult to do that now because so many different races live in the same geographic areas, so it would be more of an origin study than a modern comparison.
Interesting opening paragraph. Note that the range you give there for a "normal" body temperature is really too wide! At 95 degrees, you are well into hypothermia, and at 107 degrees, you are hospitalized and possibly near brain damage. There is nothing "normal" about that.
ReplyDeleteBut that does lead to a question that would have been good to address here to help us understand heat stress. What happens to the body when the core body temperature drops below the optimum temperature of 98.6 degrees? What happens to the internal organs, particularly the brain, and the circulatory system? Why can't it function well below this temperature?
Goosebumps *used* to be an adaptation but not anymore in humans. Goosebumps form when the tiny muscle attached to the base of the hair follicle contracts, causing the hair to stand upright. Now if the organism has a full coat of hair, this causes and air pocket of warm air to form between the skin and the hair to act as insulation. But without that heavy coat of fur, we gain no benefit. We are left with only the bumps.
An example of a short term adaptation that is *still* adaptive in humans today would be shivering, which rapidly contracts the muscles of the body to generate heat.
Good facultative adaptation.
You are correct on the developmental adaptation, but how is this explained by Bergmann and Allen's rules? How does having a rounder, squatter body shape help retain heat in the body?
Good cultural adaptation.
"For example, clothing companies may sell various types of jackets to meet the different needs of the people buying them."
That is getting to the point I was hoping students to pull from this, but can we think of other concrete uses for this information? Can knowledge on adaptations to cold climates have medical implications, perhaps dealing with issues of tissue death, or protecting the brain when the body temp is too high? Help us develop clothing that retains heat more efficiently? Can we develop new means of home/building construction that might help increase heat retention? How can we actually use this information in an applied fashion?
On the right track in the last section, and I agree with your conclusion, but can we explain more definitively why race cannot be used to 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 Katelyn,
ReplyDeleteLike always it is a joy to read your anthropology blog post. I love the pictures you selected. They illustrate your post perfectly and allow us, your readers, to visualize these adaptations. I only have one gripe and that is your font size. I know this was not intentional but It does make it sort of hard to read but your content is great! You always execute your posts so well and it really does make this class much more enjoyable. When I read your post I feel as if I'm reading an article from the journal of science. Keep up the good work!
Any comment on the actual content of the post?
DeleteHi Katelyn,
ReplyDeleteGreat job on this response. I think those of you who chose responses to cold have one of the most interesting topics, because it would seem like human beings naturally would want to stay in warmer areas, considering that humans evolved primarily in warmer areas of Africa. Nice work Katelyn!