Human Variation and Race
WELCOME TO THE COLD SIDE:
Welcome to the coldest places in the world. Places that are below zero, in the negatives, and still have human life. Ever wonder how the human body adapts to environmental stress? Colder climates disturb homoeostatic creating stress and our normal body temperature 97.7-99 F. If a person body temperature goes below normal then the body drives into different stages to adapt to the cold. When the temperature drops below 94 degrees, we develop hypothermia.
SHORT TERM:
Short terms adaptation include goosebumps and shivering in response to cold climates. Goosebumps are tiny evaluations of the skin which are caused by contractions of miniature muscles that are attached to each hair. The contraction also causes the hair to stand up when the body is cold. Shivering is another form of short term adaptation, its when the muscles contract and expand in speeding force to try to warm up the body.
FACULTATIVE:
Body fat is what helps keep the body warm in a colder climate. In different parts of the world, people like the Inuits have certain diets they consume increases their metabolic rate and allowing them to produce for body fat to help fight with the cold weather.
DEVELOPMENT:
People from colder climates are generally shorter than non-cold places. Shorter people in these environments are shorter with high body mass which allows them to keep heat better.
CULTURAL: Includes clothes, housing, diets that allow us to stay warm in cold weather. Houses keep out the cold climate trapping the warm air allowing for heaters to help maintain warm temperature throughout the house. Fireplaces, blankets, and warm drinks also help with staying warm.
THE BENEFITS:
Studying the human's adaption allow us to know how our bodies react and adapt to climate over short and long periods of time. It also helps us study in expression and cultural in relation with the environment. Changes in skin, color, height, and diets in the different environment we adapt to the needs are the body is facing and our body changes with the environment. As a result, we are able to create technology to help with the weather conditions we face in any part of the world.
Hey Genesis,
ReplyDeleteYou had a great introduction with a really good hook that drew me in. Throughout your post I thought that your descriptions and examples were easy to understand. I think you could have used more examples as evidence for your research. I also think that you missed answering the question about how environmental influences on adaptations are better way to understand human variation than with the use of race.
You lead your reader up to "hypothermia" in the first paragraph... and then you stop. :-) Keep going! What happens to the body when the core body temperature drops below the optimum temperature of 98.6 degrees? What, specifically, happens to the internal organs, particularly the brain, and the circulatory system? Why can't it function well below this temperature?
ReplyDeleteShivering IS a short term adaptation but goose bumps are no longer a functioning adaptation 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.
A couple of issues with your facultative section:
1. Diet is not a facultative trait. It is a behavioral trait, though it can contribute to biological traits, such as body shape. Facultative traits are physiological and genetic in nature and don't require any thought, action, or input from us in order for them to happen.
2. Body shape in the Inuit populations is actually a long-term, developmental trait, not facultative. Now in populations where the temperatures swing from hot to cold (temperate areas), then putting on excess weight in the cold season could be seen as a facultative adaptation.
An example of a facultative adaptation to cold stress is vasoconstriction.
It isn't just an issue of being "shorter". It is body shape that is the issue, with those in cold environments tending to be shorter AND wider, while equatorial populations tend to be longer and leaner. This is because shorter, wider body shapes have less surface area per unit of mass (and therefore gives off less body heat) while long, lean body shapes have more surface area per unit mass (and therefore gives off more body heat). Check the information on Bergmann and Allen's rules in the resources in the assignment sub-module in the Canvas course.
Good cultural adaptation.
"As a result, we are able to create technology to help with the weather conditions we face in any part of the world. "
That's closer to what I was looking for. Can you be more specific about the technology that we might create? Can knowledge on adaptations to cold climates have medical implications? 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?
Missing last section?
Hi Genesis,
ReplyDeleteI love the lay out of your post. The images that you selected for your post are great and help illustrate the content of your post. I could not help but notice that you did not really address the prompt in the last paragraph. The question was asking how we could use race to understand the variations of the adaptations listed in question two and why the study of environmental influences on adaptations is a better way to understand human variation. You only answered one part of this in your response. besides this your post is very strong. Keep up the good work!
Hi Genesis,
ReplyDeleteYou structured this post very well and followed the prompt correctly. You chose an environmental stress and labeled the different types of adaptations that the body makes. Although some of your examples given were slightly brief, I was still able to get a good understanding of what you were conveying. You did seem to leave out a response for the question asking about human variation over race classification.