Human Variation and Race Blog Post

Heat

Environmental stress

When the human body is exposed to extremely high temperatures, homeostasis is disturbed. Homeostasis which is the condition of equilibrium in the body, is disturbed when factors cause the body's normal internal environment to change. When body temperature shifts from the normal 98.6 degrees fahrenheit it can have a dangerous effects on the body such as exhaustion, heat stroke and even fever seizures which are epileptic seizures associated with high body temperatures. When body temperatures become increasingly high body functions and organs begin to shut down and fail. High body temperatures can result in disability and even death. 

Short Term Adaptation

An example of short term adaptation to combat heat would be sweating. Sweat is the body's primary coolant and coupled with evaporative cooling system the body is to cool itself and take the heat away from the body by allowing it to evaporate on the skin, "perspiration is the most important factor in heat dissipation in humans" (Jurmaine, 420).

Facultative Adaptation

An example of facultative adaptation to battle heat is skin color. Skin color is due primarily to the presence of a pigment called melanin, lighter complexioned people have what is called pheomelanin, while darker complexioned people have eumelanin. darker skinned people's skin acts as a sort of barrier against the heat and the harmful ultraviolet radiation. People with lighter complexioned skin tend to reflect the heat and take in more of the ultraviolet rays which is why European Americans are 10 times more likely to get skin cancer than African-Americans. 

Developmental Adaptation

An example of developmental adaptation is bipedalism, the ability to walk upright on two legs. Erect posture exposes less surface area to the sun and lifts the body above the ground, which keeps the body temperature cooler and reduces and reduce the dangers of dehydration and sunstroke. It also allowed our bodies to come into contact with cooler and faster moving winds. 

Cultural Adaptations

 

Examples of Cultural adaptations are swimming, fans, and air conditioning. Air conditioning and fans allows us to enjoy the heat from outside while remaining cool and comfortable in the house. We have also culturally modified our clothing to be better conducive to the heat, for example wearing shorts and tank tops in the summer. 

The benefit of studying heat in this way is that we can learn how to better adapt to our environment and how we have adapted in the past. We have discovered way's to combat the heat, we've come up with ways to enjoy the heat and still remain safe, we have learned that certain types of people are more equipped to live in certain environments than others. The creation of sunblock can quite literally save lives by blocking out harmful ultra violet radiation from the skin, without studying human variation, we may have never discovered this.

I don't think that you can use race to better understand different adaptation variations. Even in the case of facultative adaptation, knowing that people with lighter complexioned skin are more likely to be affected by certain types of ailments due to heat doesn't target any specific race. It is wiser to study environmental issues because race isn't a clear indicator of people, it isn't biological, its social. Environments can be observed and relatively clear cut conclusions can be made about them.