Human Variation & Race

1. Select only ONE of the following environmental stresses: (a) heat, (b) high levels of solar radiation, (c) cold, or (d) high altitude. Discuss specifically how this environmental stress negatively impacts the survival of humans by disturbing homeostasis. (5 pts)

Heat is one of many environmental stresses that negatively affects the homeostasis (otherwise known as internal equilibrium) of humans. For humans to survive, the human body needs to respond to an increase in external temperature. Heat can cause anything from minor medial conditions like rashes and dehydration to very serious illnesses like heat exhaustion and heat stroke. Besides affecting your health, various internal impacts are also caused by heat including slowing down brain operation of the brain, inhibiting nerve connections, and causing cramping and muscle spasms.

2. Identify 4 ways in which humans have adapted to this stress, choosing one specific adaptation from each of the different types of adaptations listed above (short term, facultative, developmental and cultural). Include images of the adaptations. (5 pts each/ 20 pts total)

Short term: Sweating is a body’s reaction to heat. Sweat is expelled from the body’s pores and the evaporation that takes place after It is expelled is what cools the body down. Heat is being transferred out of the body and into the external environment.

Facultative: Widening of blood vessels, better known as vasodilation, allows heat to travel through the skin and be absorbed by the external environment. This causes the red color the body’s exhibits when the temperature increases or when we exercise.

Developmental: Bipedalism exposed less of the body’s surface area to the sun while at the same time allowing the body to come into better contact with breezes and wind. Hair on the body’s surface also protects our skin from sun exposure.

Cultural: Air conditioning is one common answer that certain cultures use for beating the heat. A reduction in clothing is also common to see when temperatures rise. However, this is not always the case. Some cultures wear more clothes to prevent the impact of solar radiation on our skin.

3. What are the benefits of studying human variation from this perspective across environmental clines? Can information from explorations like this be useful to help us in any way? Offer one example of how this information can be used in a productive way. (5 pts)

Studying human variations in this way is beneficial because it shows why human vary in their abilities to cope and adapt to these environmental stresses. One example where we can use this information in a productive way is to explain why individuals in the Middle East have a higher tolerance to the extreme heat as opposed to individuals in the relatively mild climates in the U.S. The information we find can improve our method for dealing with heat in the U.S.

4. How would you use race to understand the variation of the adaptations you listed in #2? Explain why the study of environmental influences on adaptations is a better way to understand human variation than by the use of race. (10 pts)

Race unites people by a common historical, cultural, and linguistic background. Many confuse race with the color of your skin. Environmental stresses, like heat, affect one’s physical being rather than one’s cultural being. This means that race has little to no effect on our adaptations to environmental stress.