Environmental Stress

1.      Heat waves can lead to heat stroke and dehydration, and are the most common cause of weather-related deaths. When core body temperature becomes too high the normal mechanisms for controlling body temperature break down.  Excessive heat is more likely to impact populations in northern latitudes where people are less prepared to cope with excessive temperatures. Young children, older adults, people with medical conditions, and the poor are more vulnerable than others to heat-related illness. Heat can be a dangerous thing and can negatively impact the survival of humans by disturbing homeostasis.

Short-Term Adaptation

1.      Humans have sweat glands all over their skin. These sweat glands make it possible to loose heat at the body’s surface through a mechanism called evaporative cooling. Perspiration is the most important factor in heat dissipation in humans. This can also be dangerous because it can lead to dehydration.

 

Facultative Adaptation

Vasodilation is a facultative adaptation which helps to eradiate heat. This happens when capillaries close to the skin’s surface enlarges to increase blood flow to the skin. This is what causes flushing, redness and warming of the skin.

 

Developmental Adaptation

A developmental adaptation would be body shapes. According to Allen’s rules, longer appendages, with increased surface are relative to mass, are more adaptive to warmer climates because they promote heat loss. This rule mentions that the best body shape for hot climates is linear with long arms and legs.

 

Cultural Adaptations

Cultural adaptations would be the use of shorts, tank tops and flip flops. Most people try to wear these types of clothing during summer to try to stay cooler. Another example of cultural adaptations would be eating ice cream and cold beverages which is not seen as much in the winter. 

 

Benefits of studying human variation

1.      There are many benefits in studying human variation. Studying how ones body will react to environmental changes can prevent us from getting extremely sick or even dying. For instance, if we did not know that we have to hydrate our body while exercising in hot weather we would die of dehydration. However, thanks to science we are aware that we need to replenish our bodies with electrolyte when sweating profusely to avoid dehydration.

Understanding the variation of adaptation

2.      Before I say anything else, I will like to say that this was by far my favorite chapter. I often get annoyed when people assume I should look a certain way just because I’m Mexican. Same thing with adapting to certain environments. For example, when I go to Mexico I always get sick from my stomach. I cannot drink water from there, so I have to make sure I take my own water. My point is that, because I’m from Mexico I should be able to drink their water with no problem! No! This is why it so important to study environmental influences on adaptation because being from a certain “race” does not mean you will adapt to certain environments better than others. Adapting to the heat is not a matter of race is a matter of how your body reacts and gets used to it.