Human Variation & Race

1. Cold is an environmental stress that negatively affects the survival of humans with the possibility of death and disturbs our homeostasis. A human exposed to excessive cold is in danger of hypothermia and/or frostbite. Humans are built with a thermoregulatory center that gives us the ability to keep our body temperature within certain boundaries, even when the surrounding temperature is very different, which is a process of homeostasis. If the body is unable to maintain its normal temperature and decreases significantly, it can result in hypothermia. Hypothermia (opposite of hyperthermia), is a life threatening condition that occurs when the body's temperature drops below 95°F, and can have fatal results if not treated soon enough. Frostbite is another condition caused by cold temperatures. Human skin is not designed to withstand extreme cold temperatures, and when exposed to such a degree it can reduce the blood flow and oxygen to a certain body part which ultimately leads to frostbite. In extreme cases frostbite can result in amputation of the the harmed body part. 






2. One way humans are able to adapt to the stress of cold is with short-term adaptation.  A short-term adaptation to the cold would be the body's natural reaction to shiver. Moving around produces energy in the body which in return produces heat. (e.g. excercising makes people sweat). 

  A second way humans are able to adapt is with facultative adaptation. Cutaneous vasoconstriction is an example of a facultative adaptation, which is the initial thermoregulatory response to cold exposure. Vasoconstriction narrows the blood vessels in our body which constricts our blood flow and retains our body heat. 

The third adaptation is developmental. A form of developmental adaptation is body shape and size. It is a fact that humans with larger body masses produce more heat, which is a result of their being more cells. Another perfect example is Bergmann's rule, which states that " larger animals usually have a smaller surface area relative to their body mass and, therefore, are comparatively inefficient at radiating their body heat off into the surrounding environment." It can be demonstrated with the cube shaped boxes shown in the image.  Note that the volume increases twice as fast as the surface area.  This is the reason that relatively less surface area results in relatively less heat being lost from animals.

The fourth and final adaptation is cultural, which can come in many different forms. One form of cultural adaptation is clothing style. In colder climates people usually dress themselves with heavier and thicker clothing to keep their skin from being exposed to prevent frostbite, and keep their heat insulated to prevent hypothermia.

3. I believe studying human variation from this perspective is extremely beneficial for a better understanding of the word "race" and that these adaptations to environmental stress has more to do with the science of evolution and natural selection, rather than the opinion of race. The information from these exploration is useful for everybody, from a regular person interested in moving to a colder part of the world, to a doctor trying to a cure a patient with hypothermia or frostbite.

4. The word race has many different meanings to people all over the world. People who use race to explain the appearance or culture of someone, are people who have been taught to use the word race as more of a sterotype instead of being educated on the actual fact that race really has nothing to do with any of those things and it is actually an adaptation to our environment that has created human variation in our skin color, eye shape, body size, etc. The word race automatically can put out a sense of pre-judgment instead of understanding why it is that people do the things they do and are the way they are based on environmental adaptation.