Alma Payne
May 28, 2021
Human
Variation and Race
Discuss
specifically how this environmental stress negatively impacts the survival of
humans by disturbing homeostasis. How
does it make it difficult for the human body to maintain internal conditions
that allow the physiological systems to function correctly?
One environmental stress that negatively impacts the
survival of human by disturbing homeostasis’s is COLD. When body is stresses by
cold the body strives to control its temperature through physiological
adjustments. The body’s control system is analogous to thermostatic control of
temperature in a house with both heating and cooling capabilities. When body
temperature rises above a certain temperature, effector responses associated
with cooling, so basically the body will do things like sweat, your blood flow
will increase. My mom uses to say “rub your hands together to warm up” this was
to get the blood flow going. Another way to try to control this stressor is by wearing
appropriate clothing and doing things like (“huddling”) are far more important
in cold ambient conditions than in the heat. A second difference is the greater
role played by hormones during cold stress, including the increased secretion
of catecholamines (norepinephrine and epinephrine) and thyroid hormones. (2011.
Extreme Weather and Climate). When body temperature falls below a set point,
heat gain responses (decreasing skin blood flow, shivering) are initiated and because
the human thermoregulatory control system does not operate as a simple on-off
system, but also has proportional control and rate-of-change control
characteristics.
For each of the four types of adaptations described
above, (short term, facultative, developmental and cultural), identify and
explain one adaptation humans have evolved or developed to solve the problems
caused by your chosen stress. Use information in the assignment module to
locate these adaptations. Include one
image for each adaptation. To
summarize, you should have four separate sections here, one for each type of
adaptation, with an image for each.
Developmental Adaptation-
when it comes to developmental adaptation, race would be considered a subspecies’. People who have lived together for a long time may have some alleles in common (for example, those that code for skin color or hair color), there is more genetic variation within races than there is between races, but skin color and hair color are some that I can think of.
Cultural Adaptation-
The theory of cultural adaptation refers to the process and time it takes a person to assimilate to a new culture. It is not always an easy transition. The example I can think of is a foreign exchange student coming to the U.S unable to read signs or understand the American Culture, they will have to adapt the American way of doing things. The image I chose is to show the different cultures and how they say hello, it shows how we all have a universal language (the human language), its just demonstrated in different ways.
Short Term Adaptation-
These types of traits allow an organism to respond quickly to changes in the environment to maintain homeostasis (i.e., normal physiological conditions). The response is quick and the return to the original expression of the trait is rapid once the stress is removed. An example of this would be sweating in response to heat stress. An example of short term adaptation is our body’s ability to adjust to temperature as defense mechanism, like in the picture the man is cold he wearing warm clothes and the body is shivering, when the body shivers it is increasing the blood flow which is way to warm the body, it is your bodies way of relieving that stress.
Facultative adaptation-
Facultative traits are genetic traits. They do not require a change in an organism’s DNA but they do involve turning on and off genes to alter a phenotypic expression in response to an environmental stress. Sickle cell anemia is an inherited red blood cell disorder in which there aren't enough healthy red blood cells to carry oxygen throughout your body.
What are the benefits of studying human
variation from this perspective across environmental clines?
A benefit to study human variation is to better
understanding ourselves. Human Variations concerns itself with what most of us
consider to be the most interesting species on earth the Homo sapiens. A second
reason for studying Human Variation is its practical value for human preservation
and the discovery and description of the genetic contribution to many human
diseases, this had been why we have a cure for so many diseases and is also why
this information is very useful to us.
Is it possible to use race to understand the variation of the adaptations you listed in #2? Yes, it possible to use race to understand the variation of adaptations because, humans exhibit biological diversity. The evolution of the human species and how our biological variation can be similar or different from that of other species of animals like other primates and apes.
Studying the human race and the different sub species and gives us the ability to understand how different biological traits developed over evolutionary time.
Hi Alma,
ReplyDeleteThis was a very good blog to read an interesting as well. You have explained many points in a very simple form. I agree to your point on studying about human variation have helped us find a cure for many un imaginable diseases in order to save the humankind's life. This study is something which each and every individual should know about.
Hey Alma!
ReplyDeleteI really enjoyed your post. I really like how you explained each version of adaptation and its definition. You gave examples and explained to unfamiliar readers what each adaptation meant. Great job!
Opening: What you are actually discussing here are the adaptations to heat stress, not the problems with heat stress itself. The key question in this first section is how cold stress negatively impacts homeostasis, not how the body tries to adapt to it. So what happens to the body when the core body temperature drops below the optimum temperature of 98.6 degrees? Why can't it function well below this temperature?
ReplyDelete(Note, also, that sweating is a response to heat stress, not cold stress.)
Short term: Yes, on shivering. No need to mention sweating, as that is a response to heat stress, not cold stress.
Facultative: Sickle cell anemia is a disorder, not an adaptation. It does have the added feature of providing immunity to malaria in the heterozygous form, but the condition of sickle cell is not an adaptation at all to cold stress. Remember that an adaptation HELPS the body more than it hurts it. An example would be vasoconstriction, which helps to retain heat by preventing blood from going to the skin's surface.
Developmental: Missing?
Cultural: Missing?
Okay in your next section. With regard to genetic diseases, this only applies if the disease (or cure) can be connected in some way to environmental adaptations. That only applies to a narrow segment of diseases. Is there a way we can use this information in some concrete, technological way? Can knowledge on adaptations to cold climates have medical implications? Help us develop clothing that retains heat more efficiently? Can we develop new means of home/building construction that might help increase heat retention? How can we actually use this information in an applied fashion?
In your final question, you are assuming that race is a biological concept and can therefore be used to understand the biology of our adaptations. Is that a valid assumption? Can race really be used to understand human variation? Understand that it is perfectly valid to consider answering this with a "no".
To answer this question, you first need to explore what race actually is. Race is not based in biology but is a social construct, based in beliefs and preconceptions, and used only to categorize humans into groups based upon external physical features, much like organizing a box of crayons by color. Race does not *cause* adaptations like environmental stress do, and without that causal relationship, you can't use race to explain adaptations. Race has no explanatory value over human variation.
Hey Alma! I quite enjoyed reading your post. I like how you talked about the heat stress aspect during the short term adaptation information. It felt very informational. Not only that but also the Facultative adaptation part was sublime. Good Job!
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