Human Variation and Race

The environmental stress of heat affects humans by causing a body to sweat in an attempt to cause homeostasis.  When that is not enough, heat can also cause rashes, headaches, cramping, heat stroke, and even death.  This occurs because the body is unable to displace or level out the level of heat the body has taken in, usually from ambient conditions.  

Short-term adaptation – when the ambient temperature rises to a level that causes the body temperature to rise above a level that the body can maintain homeostasis, sweat output is increased.  This is done as a short term adaptation to respond to higher level of core heat.  This is often times seen in athletes during sporting events in addition to simply happening on very hot days.  The level of sweat output can vary based on the humidity in the air.  The higher the level of humidity the less effective sweating is as a short-term adaptation.  Evaporative cooling, or sweating, is only effective in relatively dryer climates.  When the humidity is higher sweat is unable to evaporate, therefore making it more difficult to continue sweating.  This reaction to higher humidity is called hidromeiosis.      

       

Facultative adaptation – when the body is unable to cool using short-term adaptation, such as sweating, then we will often times see flushing or reddening of the skin.  This is due to vasodilation of the peripheral blood vessels.  Vasodilation occurs when the blood vessels widen causing an increase in blood flow close to the surface of the skin.  The increase flow of blood pulls heat from the core of the body and displaces it near the surface allowing for cooling.  The heat is transferred via circulation throughout the body.

Developmental adaptation – as it pertains to environmental stress of heat, an example of developmental adaptation is best explained describing one way simple radiation is accounted for when it comes to cooling the human body.  One way of explaining this is to use Allen’s Rule.  Simple radiation is when heat is dispersed throughout the surrounding environment.  Essentially, two bodies of the same mass, but made up of different shapes, can have different cooling and heating features.  A human being that has a lesser amount of surface area has less area for heat to dissipate off of.  You would probably see someone of similar shape and size in a colder climate because it's easier for the body to hold in heat.  A person of the, let’s say same weight, but that is very tall has, more surface area throughout the trunk, legs, and arms of the body for heat to dissipate off of.  You might see someone of similar shape and size in warmer climates such as the likes of east Africa. 

Korean designed "sushi roll home"

Cultural adaptation - as it pertains to environmental stress of heat, Cultural adaptation seems to be the simplest of all to understand.  As human beings we can adapt to heat by changing how we live.  For example if a person is accustomed to cooler temperatures then they might choose to find a job that provides evening hours.  Other examples of cultural changes would be to change how one dresses or how they wear their hair.  One might also change which portion of an area they live or they might change their living arrangements to compensate for the heat.  Some might take the time to specially design a home that compensates for heat, cold, humidity, winds, etc...

Studying human variations like these can be beneficial in several ways.  From a commerce point of view, knowing the demographics of an area will most certainly help in the marketing of whatever product one might be producing.  This is especially true of clothing.  Another benefit would be when attempting to provide the ability for people to grow food in certain areas.  An example of this would be the designing of crops to grow in areas where famined or impoverished people have migrated to.  

In its most simplest form race could be used when looking at why certain people might be more susceptible to death in extreme climate conditions.  An example of such conditions would be heat waves that hit certain areas in waves.  In the United States over 4000 people die each year from heat stroke.  If understanding different variations of adaptations among different races can decrease that number the United States would be better off for it.