Human Variation and Race

Environmental Stress: Cold

Homeostasis is typically disturbed by the cold when the body is exposed to extremely cold temperatures.  When this happens, the body’s temperature lowers below the normal healthy temperature of 98.6 degrees Fahrenheit and risks hypothermia.  Hypothermia is a medical emergency where the body is unable to produce heat at the same speed that the body is losing heat and therefore the overall body temperature lowers and the body’s energy decreases.  A low body temperature is dangerous as it can slow heart rate, brain activity and breathing.  Therefore, the cold negatively affects homeostasis as it can cause hypothermia, which can be a danger to survival if treatment is not urgent and persistent.

Short-Term Adaptation

In response to cold stress, a short-term adaptation is shivering.  Shivering is a temporary involuntary mechanism triggered to maintain homeostasis.  The body uses small, generalized and uncoordinated muscle contractions to create heat. The increased muscle activity produces some heat. 

Facultative Adaptation 

A facultative adaptation in response to cold stress is vasoconstriction.  Vasoconstriction is a normal physiological response of narrowing the blood vessels near skin surface (Dennis O’Neill, http://anthro.palomar.edu/adapt/adapt_2.htm).  Many times, heat is lost when warm blood travels close to the skin surface.  This contraction of blood vessels near the skin reduces the amount of warm blood that flows close to the skin surface and therefore reduces amount of heat lost.  

Developmental Adaptation

Another way the body protects itself from cold stress is through the developmental adaptation of having a thick fat layer around the body and vital organs that provides insulation and the retention of heat.  People who live in colder climates are typically larger than others.  Their bodies have developed a thicker fat layer in order to adapt to the colder climate and essentially survive.

 Cultural Adaptation

Many humans dating back hundreds of thousands of years ago started wearing clothing in order to keep warm.  Many Neanderthals and hominids much more recent than them used animal skin and fur for another layer of insulation and protection.  The use of clothing as a mechanism against the cold is considered a cultural adaptation to the cold stress.  

The benefits of studying human variation and race from this perspective across environmental clines is how we can develop our ways in which we stay warm in order to survive through analyzing how others have approached this task.  Everyone thinks differently and has different experiences; therefore it is best to learn from each other in order to find the most effective way to cope with the cold weather.  Hypothetically for example, while people living in the Middle East may only be using thick wool clothing for insulation when outdoors, countries like the United States are selling small packets that generate heat.  You can hold them in your hand or stuff them in your shoes and use the heat to stay warm.  People in the Middle East could benefit from studying ways in which we stay warm and they could start using these heat packets.  

I would not use race to understand the variation of the adaptations for cold stress as race does not matter.  Different races do not have advantages or disadvantages in dealing with cold stress compared to others.  The study of environmental influences on adaptations is a better way to understand human variation rather than race because since there is no connection with race, the humans must have adapted to the different environments over time and in variation as humans developed in many different parts of the world individually.

Language Blog

Without any version of symbolic language, communication is incredibly frustrating and difficult for both parties in the conversation.  For my two partners, Holly and Lauren felt irritated at the fact that I could not respond or make any indication of what I was thinking.  I tried to communicate with hand signals and facial expressions to show my agreement and understanding, but it was frustrating when my friends did not understand what I was trying to say.  When Holly or Lauren would turn to specifically me to say something, they started talking slower and with simpler language as if I did not understand.  The problem was not that I couldn’t understand them, rather it was the fact that I was unable to respond.  The conversation tended to lean towards just Holly and Lauren talking, rather than keeping me involved.  Though they wanted to hear my opinion, the struggle to share my thoughts was tiring and I slowly stopped responding and tended to listen instead.

            My partners were definitely in control of the conversation.  As said before, the conversation swayed away from talking to me and I felt left out.  It was very frustrating when I had very relatable comments I could have contributed to the conversation but was unable to do so.  Whenever Holly or Lauren asked me a question and I was unable to add sufficient input, they changed the topic.  The topics tended to change quite frequently as they tried to find a topic I was able to communicate about.  The powers of the conversation were in the hands of my friends because since they were able to be a big part in the dialogue, they were able to slow down or speed up the talking, change the subject, and add commentary. 

            If my friends and I were representing two different cultures, my friends’ culture would be advantageous over mine.  Holly and Lauren’s culture allows the individuals to take a subject of conversation to the next level and involve not only facts, but also ideas much deeper using opinions and personal perspectives. Cultures with a more complex and advanced language will generally be more advanced in their society and environment.  The speaking culture might look down upon the cultures without a developed language and think of them as inferiors.   The culture of many monks living in Asia who have taken the vow of silence compared to the westernized culture of many large cities in Asia as well as all over the world mirrors this situation.  Though the act of not speaking was a choice, the monks live incredibly different lives than us, much of which is because of their vow of silence. 

            I thought this part of the assignment was going to be much easier, but I found so much of our language involves non-verbal communication.  When you picture people conversing, you don’t see people talking in monotone, without any hand movements or facial expressions.  In order to show the emotion, you use these non-verbal signals.  They are incredible important.  I had a very tough time not being able to raise or change my voice.  I found myself using a lot of descriptive words and talking a lot about how I felt in order to compensate for not being able to use physical embellishments.  My friends found it funny to see me without any expression.  They were also confused, and thought it was hard to figure out how I felt about what I was talking about, like whether what I was saying was a joke or something serious. 

            Body language and the ability to read it are extremely useful because it can tell so much about what the person is saying.  In all aspects of life, you can tell someone’s feelings, intentions, and needs by merely watching their body language.  For survival and obtaining resources, you can use your body language to intimidate predators and prey and for reproduction, you can indicate if you would like to reproduce or if you are attracted to that individual.

            I can tell whether someone has trouble reading body language because they seem to be unaware when you might be trying to tell them something without speaking it.  For example, Holly could definitely tell how frustrated I was in the first exercise by the way I was standing and my facial expressions, yet Lauren did not notice how frustrated I was.  It seems Lauren lacked the ability to read my body language intently.   A situation where it might be advantageous to not read body language might be when a person is under the influence of drugs or alcohol.  When someone is under the influence, many times, that person does not realize what he or she might be communicating with his or her body.  During times like these, it would be best not to read into the signals their bodies are sending. 

Piltdown Post

In December of 1912, archeologists Charles Dawson and Arthur Smith Woodward claimed to have discovered human-like findings dated 500,000 to a million years old.  Dawson found pieces of a skull and a jawbone with two teeth in a gravel pit in Piltdown in Sussex, England.  These findings would have shown that there was early human existence a longer time ago than what has been said, with a large brain that set it apart from apes or other species.  This finding could have been the ancient common ancestor of apes and humans scientists have been trying to find for decades.  The evidence would have had a dense impact on confirming the theory of evolution, as well as our thoughts on early human development in terms of brain size and locomotive patterns.  The hoax was discovered years later using new technology on radiometric dating and identification of species, while closely examining the findings and noticing the skull and jawbone were from different species.  The scientists also revealed the teeth were filed down to resemble a human’s teeth structure and the other findings were artificially stained to closely resemble each other.  The skull was found to be a modern human’s skull and an orangutan’s jawbone.  The responses of the scientists involved included assuming Dawson and Woodward created the hoax or Martin Hinton, a volunteer who helped analyze the findings and possessed a trunk with a ton of findings dyed just as the Piltdown man’s findings were.  Dawson and Woodward both passed away before the hoax was revealed, but Hinton never claimed he was the perpetrator. 

            Many human faults came in to play here in the Piltdown hoax including greed and lack of suspicion.  The scientists responsible for the hoax let greed overtake them, as they wanted the fame and glory of finding what scientists have been trying to find for many years.  Science definitely relies on truth and dignity, and this hoax shows that scientists have valued their own fame and prominence over the success and truth of science.  Also, many of the other scientists faulted in addressing their doubts of the findings because they were afraid to confront or refute the work of famous scientists.  Science must accept all perspectives and opinions as discovering truth uses the work of many, not merely one finding.

            The Piltdown hoax has shown how strong and reliable the scientific method is.  The aspect of testing the hypothesis and evidence and analyzing the results with the hypothesis is the backbone of the process. Also, the aspect of repeating the experiments and tests many times with multiple scientists is the key to confirming the conclusion.  When dozens of scientists analyzed and tested the Piltdown findings, surely, the scientists finally discovered the truth and the results became clear.  Using a microscope to analyze the teeth and discover the unnatural scratches of files was a great way to truly examine the anatomy of the teeth.  These processes showed that the flat style of the teeth was not because the jawbone is of human ancestry, but because someone shaved it down to create the hoax.

            I do not believe there is a way to remove the “human” factor of science because I believe science is set on the foundation of theory.  The scientific method cannot even be started without a thought, theory, or hypothesis.  We need the thoughts and assumptions.  I believe a way to minimize the error is to analyze more thoroughly and with more tests.  I also believe we need to make sure we have enough evidence to change a hypothesis or theory into a conclusion or a fact.  I would not want to take out the “human” factor of science or we would not improve our findings and conclusions.

            A lesson we can take from this event would be to completely verify our source with many tests, scientists, and evidence before we claim the source as true and factual.  I believe we took a huge step back with these many decades of false evidence.  The scientific community must be extremely thorough in its testing, claiming, and publishing.

Comparative Primates: Size and Sexual Dimorphism

1.     Lemurs

a.     Though lemurs originated in extremely tropical regions such as North America, lemurs can now only be found on Madagascar and nearby Comoros Islands, islands just southeast of Africa.  Madagascar and the Comoros Islands are tropical islands with variations of hot, humid, and dry weather.  The islands contain a large variety of vegetation and species.  Madagascar is a fairly large island while the Comoros Islands are rather small.

b.     Typically, there are no sexual dimorphism with lemurs, but a few species of lemurs show sexual dichromatic, which is this difference in fur color between genders.  Lemurs are fairly small primates, weighing on average five to seven pounds.  However different species show different sizes, which can range from being just slightly bigger than a mouse to the size of a large domestic dog. 

c.      Since lemurs have a large amount of competition from other animals on the island, one way to survive is to live in the trees and reach the hanging vegetation.  They do not need a large body size to prey on other species; therefore their small body size was an adaptation to the environment.  With the small body size, the lemurs are able to swing and jump within the trees with ease.

2.     Spider Monkeys

a.     Spider monkeys can be found in the tropical rainforests of Central and South America.  Using their tail as a third limb, spider monkeys live in the upper parts of the trees in the tropical rainforests, swinging from branch to branch with ease. 

b.     Comparative to the lemurs, spider monkeys have very little sexual dimorphism.  The males tend to be slightly larger, at an average of roughly 25 pounds while the females are on average 21 pounds.  Other than the size, the spider monkeys can be indistinguishable between genders.

c.      Spider monkeys might have a smaller size in general because of their environment.  Living in the trees, having to swing from branch to branch, the spider monkey has an advantage with the smaller size.  I could also connect the size with the diet.  Though spider monkeys are omnivorous, they tend to eat a lot of vegetation since they live up in the trees.  The lighter diet could be a cause of the smaller body type. 

3.     Baboons

a.     Baboons have a more various living environment.  They can be found in savannas, rainforests, and the mountains of Africa and Asia.  They are semi-terrestrial animals, so they can live in both the trees and the ground. 

b.     The female and male baboons have big distinctions between the two.  Males are significantly bigger than females, and much more aggressive and protective of their females.  Males can be up to three times larger than the females.  Males also have a mane around their head and can have white or silver fur, while females are typically brown.

c.      The much larger body weight compared to the other two primates might be because they live closer to the ground and have a heavier diet.  The larger body type might be for defense, since they have more prey being closer to the ground or on the ground.  A reason there is such sexual dimorphism with baboons might be because the males take on a stronger role between the two, dominating their surrounding compared to the females.

4.     Gibbons

a.     Gibbons primarily cover a large area of Southeast Asia, usually inhabiting the middle to upper levels of the trees in the tropical and sub-tropical rainforests.

b.     Gibbons typically have little sexual dimorphism, yet males are slightly larger than females in body type.   Their body weight usually averages between 15-25 pounds, with elongated arms spanning over five feet.  Gibbons also have a loud call, used for warning and mating, and males usually have a louder call than females.  

c.      Their lightweight and lanky features are great for swinging through trees and racing away from predators.  The mating call might be a reason why male gibbons are not different from the females.  The males do not need to be bigger or different to attract the females, for they have the loud mating call.

5.     Chimpanzees

a.     Chimpanzees typically cover the middle and western regions of Africa in the savannas and rainforests.  They are semi-terrestrial animals depending on environment.

b.     Chimpanzees have a much denser body weight compared to the other primates analyzed.  Their weight can range from 70 to 250 pounds, females being much smaller than the males.  The males are also about a foot taller than the females on average. 

c.      The large body weight helps the chimpanzees fight off predators and dominate their prey.  The males’ larger size than the females are to attract the females and compete with the other males for reproduction.  The long arms are for swinging from tree to tree with ease. 

Conclusion:  The environment has a large impact on the differences in size and behavior with the primates.  Primates that live primarily in the trees and have a smaller diet usually have a smaller body size, while the primates that live closer to the ground and have more prey/predators have a larger body size.  I also noticed that the primates where the male and female share the parental responsibilities have little sexual dimorphism; while the ones with more mates and the females control the parenting have more sexual dimorphism, like chimpanzees and baboons.