Short-term adaptation:
Shivering can also cause a short-term warming effect. Shivering causes the muscles of the human’s body to increase activity. The increased muscle activity in shivering results in a boost of temporarily heat production.
Facultative adaptation:
The Hunting phenomenon is an unusual reaction of digital blood vessels exposed to cold; vasoconstriction (narrowing of blood vessels near skin surface) is alternated with vasodilation(dilating the peripheral blood vessels) in irregular repeated sequences, in an apparent hunting of equilibrium of skin temperature.
Developmental adaptation:
People who live in extremely cold environments benefit much more by having a stocky body with short appendages rather then a long lean body because the shorter body type is more efficient at maintaining body heat. Since the shorter body type would have relatively less surface area compared to body mass their bodies might hold more fat as a result they can produce more heat in the colder climates where they live.
Cultural adaptation: There are many ways humans can deal with the cold . Some effective cultural response to extremely cold temperatures is the use of insulating clothing, indoor fires, and even sleeping in family groups with bodies pushed up against each other. Some cultures even drink strong alcohol as a way to increase temporarily body heat.
The benefits of studying human variation in regards to clines rather than other classifications is that they are less biased on the organizer's beliefs, more accurate, more holistic and give a wider view to humanity that can be seen as a spectrum of adaptations for specific niches. The information we gather from these kinds of explorations is useful because it illustrates an true depiction of human evolution and adaptation, rather than lumping people into categories over insignificant distinctions. This information can be used in a productive way by anthropologists to assist other groups of people who fall under the same niche. Adaptations one group has spearhead may be applicable to another group.
The word “race” has undergone many different meanings. Race is a undependable organizational system for stereotyping the human race. In example #2, these adaptations are not race specific; therefore, race would stand for any population who lives in very cold territories. There are certain patterns among populations that are directly linked to environmental stress. Instead of assimilating the word “race” with skin color or nationalities, people should understand the biological adaptations as a whole, which are really related to the environment.
Good description of cold stress, though getting sick is not a direct result of cold stress. It is a possible secondary effect. The primary effects are frostbite, the shutting down of vital organs and death.
ReplyDeleteGood descriptions of your adaptations. I've never heard of your facultative traits labled the "hunting phenomenon". The scientific reference is much more cumbersome: alternating vasoconstriction/vasodilation. It's not that the body is "hunting" for equilbrium. It is dangerous to the tissues near the skin surface to keep the caplillaries constricted for extended periods of time, so occasionally the capillaries dilate to allow the surface tissues access to oxygen and nutrients. It's a balance (equilibrium) between heat retention and tissue death.
Okay on your cultural traits, though make sure you understand that alcohol doesn't raise the body temperature at all... in fact it can lower it, which gives the illusion of warmth relative to the air temperature. Alcohol consumption in cold climates is actually maladaptive.
Good description of the benefits of the adaptive approach.
"Race is a undependable organizational system for stereotyping the human race. "
Very well said. Instead of "undependable", you could substitute "subjective" and "biased". Regardless, there is no causal relationship between race and human variation. Without that causal relationship, you cannot use race to understand why human variation exists.
Great post. I find that its interesting that short people adapt better in the cold. I would think it would be large people with great layers of fat to keep them warm. Also i would think that people who grow up in those extremely cold conditions would grow be hairy to keep them a little bit warmer.
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