1. Heat
can negatively impact human homeostasis in many ways. Heat can cause a person to lose water within
their body which can lead to dehydration. Heat also can lead to heat stroke
when a person’s body has trouble regulating their temperature which then in
turn causes unconsciousness or fever. Extreme cases in dehydration and heat
stroke can lead to death. Less severe effects of heat can be exhaustion and an
irritable mood.
2. Short term adaptation to heat includes
sweating to cool off the body’s internal temperature and maintain homeostasis.
Developmental adaptations to heat
can include the loss of the general amount of body fat a population carries over
the course of generations. When a person has less body fat they can regulate
heat better and maintain homeostasis. Also there is likely to be less body hair
as there is no need for it with the prolonged exposure to heat.
Cultural Adaptations to heat vary
in some methods but are relatively the same. Some cultures use an electric fan
or a household cooling system in order to reduce the heat, others may use a
paper fan. Some cultures carry umbrellas with them for shade when there is heat.
Many people often wear less bulky clothes or leave more of their skin exposed
with their clothes in order to reduce heat as well.
3. There
are many benefits to studying human variation across environmental clines. This gives us a better understanding of us as
humans and how we adapt to different environmental stresses. It can teach us
how our bodies react long term over certain n stressors and also we can learn
about different ways populations chose to respond to these stressors as a
group. An example of this could be the discovery of skin cancer in relation to
the amount of melanin a person’s skin tone holds. People with darker skin tones
are less likely to suffer from skin cancer while people with lighter skin tones
are more susceptible to it. This discovery can teach us about the variations of
people and how their skin adapted over time in order to suit the environment they
lived in.
4. Race
can be the prolonged exposure to different environmental stressors. With the
stressor being heat, a certain race of people can be naturally thinner than
others in order to reduce their body temperature; this race can also have less
body hair in order to reduce heat as well. The study of environmental impacts
on human variation and how humans adapted to it is better than studying it by
the means of race in many ways. Studying race can lead to negative stereotypes
and racism if you are looking at human variation that way. It can lead people
to believe that a certain group of people are superior to others. When one
studies environmental differences as an effect on human variation it can
portray people in an equal way. It will show that we are all of the same
species, there are only slight differences in our appearance because of the
adaptations that have occurred over time in an effort to better suit the environment
groups of people lived in.
Great post. I especially enjoyed your view on race vs variation as a means of studying adaptations. I never considered it from the standpoint of perceptions of superiority, or racism, or even equality. That is a very valid point though, as we still have a lot of that going on, unfortunately. I did think of it in terms of how many thousands of years humans have been migratory, and how members of one group of people have produced offspring with members of another group perhaps much further back than any recorded history. I never really considered race to be any kind of accurate depiction of traits or adaptations, but rather a societal label. But, different societies would probably label races differently than other societies. Thank you for sharing your view.
ReplyDeleteHeat itself doesn't lead to dehydration. It is the body's attempt to cool itself in high heat that leads to dehydration, so this is a secondary problem, not a direct result from heat. It's important to recognize this distinction to help you distinguish traits that help maintain optimal body temperatures from those that deal with secondary, indirect problems.
ReplyDeleteYes, sweating is an adaptation to high heat, but how does it work? Is it the sweat itself that cools the body or the evaporation of the sweat?
You are the first person to mention the reduction of the metabolic rate as a way to cool the body. That is correct. Sort of like turning down the thermostat on a furnace.
It isn't just less body fat that helps but the shape of the body and the relationship between the surface area and the body mass. Populations in hot climates tend to have high surface area to body mass ratios, allowing for more dissipation of body heat through the skins surface, as per Bergmann's rule. There is speculation that humans lost body hair for a cooling purpose, but that is still up for debate. Why are humans the only ones to lost their body hair? What about all those other mammals in hot climates? Or could something like sexual selection have played a role there instead?
Good discussion of the cultural adaptations.
Good explanation as to the practical implications of the adaptive approach. I agree that the medical and health community could use this information to our benefit.
"With the stressor being heat, a certain race of people can be naturally thinner than others in order to reduce their body temperature"
But you are just using the adaptive approach and tacking on race to it. That isn't really using race to explain why human variation exists.
I agree with your final conclusion on the value of race (or lack thereof) but your argument required clarification and it helps to understand what race actually is. Race is a subjective social construct, not a biological one, so how could we use it to objectively understand biological traits? There is no causal relationship between race and human variation, such as there exists between the environment and human adaptations. Without that causal relationship, you can't use race to explain why that variation exists. It can only describe and categorize.