Human Variation and Race Blog

COLD:   

     A normal human body temperature is 98.6 degrees.  When the human body is exposed to extremely cold climates it must be able to retain heat or increase heat production, if not the result could be deadly.  Hypothermia begins when the body temperature drops to 94 degrees and if the body’s core temperature continues to drop, it could eventually lead to death. This environmental stress negatively impacts the survival of humans by disturbing homeostasis.

4 Ways Humans Have Adapted :

Short Term – The body has adapted to staying warm by shivering, increased muscle activity produces body heat.

Facultative – Vasoconstriction restricts blood flow to the surface of the skin, reducing heat loss at the body surface.  Vasodilation expands blood vessels, increasing blood flow to the skin, restricting energy loss and retaining heat. The body’s adaptive ability to cycle between the two is known as Lewis Hunting Phenomenon.

Developmental – Body size and shape in cold environments has evolved. According to Bergmann’s and Allen’s rule a stocky body with short appendages is more adaptive in cold environments. This allows the body to retain heat and minimize heat loss.

Cultural – Some people drink alcohol to stay warm but a more effective way humans have adapted to the cold is by wearing insulated clothing, staying indoors, or warming up next to the fireplace.

     Studying human variation from this perspective across environmental clines can help us understand how people survive in these environmental stresses.  By studying how particular traits are expressed in certain environments can help prepare us when entering a new environment.  For example, we know that when we are in cold climates we have to maintain a normal body temperature and prevent hypothermia.  In order to do this we wear insulated clothing, build a fire or stay indoors.

          

     I would not use race as a tool to understand human variation.  Race is not a tool it is an idea.  The study of environmental influences on adaptations is a better way to understand human variation than by the use of race because it can help people understand the differences of people as a whole rather than a specific group.  We are all human and we can all freeze to death in extremely cold climates, the color of your skin will not matter.

Language Post

     While engaging in conversation with my daughter is always a joy, this experiment took it to a whole new level.  Conversing without words was quite the task.  My attempts to solicit or respond to a question usually ended with my palm to my forehead.  At times, I would catch myself trying to play charades.  On the other hand, my daughter was able to carry on conversation whether I responded correctly or not.  She always seemed to be three subjects ahead, whereas I was still trying to get her to understand my first message.  If I was trying to talk about our dog, she was talking about the kitchen.  For the most part this assignment was frustrating, I could not imagine not being able to talk.  In this case my daughter took full control of the conversation.  The fact that she was in complete control, gave her the ability to change topics, ask and answer the questions, as well as exclude me from the conversation.  As a matter of fact, if there were not a fifteen-minute time limit, she would probably still be talking.  The balance of power was definitely tilted her way and she enjoyed every minute.  Once again with her in control of the conversation, it didn’t matter what I was trying to say.  She would simply move on to the next subject.

     If we were two different cultures where one uses spoken language and the other does not, the culture with the spoken language would have the advantage in communicating complex ideas within their population.  The culture with the spoken language would be able to share information verbally, visually, and with a hands-on approach.  The culture that does not use spoken language may only communicate visually and with a hands-on approach.  The lack of verbal communication inhibits this culture.  The speaking culture in this case may look down upon the culture that does not use symbolic language as if they lack intelligence.  A modern situation that might resemble this relationship between a culture that can speak and culture that cannot would be parents and their newborn baby.  A baby is unable to express itself verbally therefore making it difficult for the parents to understand the needs of the infant.

     Speaking without any physical embellishments was no easy chore.  Especially attempting this with my daughter.  I felt like the teacher from Ferris Bueller’s Day Off, lacking complete emotion. However, this time around she didn’t have the upper hand.  I was able to say exactly what I wanted to say, I could change the subject, and I actually felt like I was included in the conversation. The only problem was that it was one boring conversation!  So boring, that during our discussion she started playing her ukulele.  The lack of body language and vocal intonation was nearly impossible.  I found that to be very difficult and as previously stated my daughter found me to be very boring.  She seemed uninterested to the entire conversation.  My daughter had no problem comprehending; it was the absence of emotion on my part that kept her from engaging in conversation. 

     Non-speech language is an important role of effective communication.  This type of communication plays a vital role alongside verbal communication.  It allows the audience to capture feelings from the speaker.  Our emotions are displayed in our body language.  If a person were to read our body language they might see some of the following: a smile that represents happiness, a shoulder shrug may signify unawareness, eye rolling could imply disbelief or disgust, and hands on your hips might suggest dominance.   

     The adaptive benefit to possessing the ability to read body language is vital in our lives.  We have become dependent on this ability.  When we communicate with each other we tend to seek each other’s emotions.  For example, we might try to motivate somebody when they seem discouraged or know to console someone when they are sad.  The ability to read body language can help a person survive, obtain resources, and reproduce successfully by being able to understand the message that is being conveyed.      Realizing that somebody is a threat just by looking at their body language will automatically put you on guard.  You might fight, run, or even hide.  The look of a hungry, homeless child will provide them food, clothing and shelter. Additionally, males and females flirt with each other in hopes of finding a mate and eventually producing offspring.

     The blind are an obvious group of people that have difficulty reading body language.  Some children with learning disabilities may also have trouble-understanding non-verbal language.  A situation where there might be a benefit to not reading someone’s body language could be seen in people who are intoxicated or under the influence of drugs. The alcohol and drugs alter the normal state of mind, thus producing unreliable body language. 

The Piltdown Hoax

A hoax, so cunning that it puzzled scientist for over 40 years in the early 1900s was known as the Piltdown Hoax.  In a village in England named Piltdown, an amateur archeologist by the name of Charles Dawson claimed to discover a part of an ancient human skull.  Subsequent this find, Dawson requested the assistance of Geologist Sir Arthur Smith Woodward of the Natural History Museum and French Paleontologist Father Teilhard de Chardin.  The three made shocking fossil discoveries together.  The fossils were a miraculous find in that primitive human fossils had previously been found in France, Germany and Asia, but not in England.  Most significantly, these fossils appeared to be over one million years old, which would have told us that humans were here much earlier than previously thought.  After continuous digging, a jawbone with human-like teeth was unearthed and apparently belonged to the earlier mentioned human skull.  In December of 1912 Woodward announced their discovery to the public.  The newspaper named this find the “Piltdown Man.”  There were mixed emotions among the science community.

The impact amongst the science world was tremendous.  Some scientist hailed their accomplishment with the belief that England had ancient human fossils and their ancestors may be the eldest of all.  Anatomist, Arthur Keith supported Dawson because the fossil discovery backed Keith’s theory that humans developed big brains before walking bipedally. Throughout the years more fossils were found at Piltdown and silenced the skeptics.  Other scientist felt this to be a distraction within the science community.  People had their suspicions but did not dare challenge these men due to their prestige nor did they want to go against the establishment.  Piltdown Man led research on human evolution over the next decade, though no fossils were ever found at Piltdown after Dawson’s death in 1916.  In the early 1920s, scientist found ancient remains in Asia and Africa, except that these fossils did not seem to relate to the Piltdown man because their fossil discovery was less human and hundreds of thousands of years after Piltdown man.

The Piltdown hoax was uncovered in the early 1950s by a professor at the British Museum by the name of Kenneth Oakley.  Oakley discovered that artifacts were stained, teeth were filed down to look human-like, and material was removed with a knife after being fossilized.  Professor Oakley analyzed the fossils through the technique of fluorine analysis.  He used this technique to date the fossils and uncover the hoax by proving first; the skull that Dawson discovered was much older than the jaw.  Secondly, the difference in the fluorine content in the fossils also led Professor Oakley to reveal that the jaw belonged to a female orangutan and not a hominin. 

Allowing pride and self-interest to get in the way of objectivity are the human faults that came into play in the Piltdown Man Hoax.   These faults impacted the entire scientific process.  Scientist and the people became vulnerable to the lies.  They believed what Dawson found was so miraculous and of course a man of his prestige would not deceive them.  The community lost trust in science. 

I do not believe removing the human factor from science would reduce the chance of errors like this happening again, nor do I think the human factor should be removed from science.  I believe errors are bound to happen whether the human factor is involved or not.  It is the involvements of the human factor that discover these errors.  Scientists learn from these errors and challenge them.  In this case Professor Oakley challenged Dawson.

      When it comes to taking information at face value from unverified sources, the Piltdown Man Hoax has taught me to be aware because scenarios such as this can and will happen.  I should always verify my sources and not take information at face value because I may become vulnerable to the lies and lose my trust in science.  

Comparative Primates - Locomotor Patterns

Lemurs (Prosimians/Strepsirhini)

Environment:  ring tailed lemurs are found on the Island of Madagascar off the eastern coast of Africa and the Comoro Islands.  There are many trees with food.  They are the only non-human primates on the island, so there is no competition from apes and monkeys.

Locomotion:  ring-tailed lemurs are terrestrial, they spend time in the trees but mostly on the ground.  Ring tailed lemurs are diurnal.  These lemurs move quadrupedally on branches of trees and the ground, they are vertical clingers and leapers. Their tails are used for balance to stand or jump from one branch to the next.

Lemurs are sociable and eat mostly fruit and leaves; their climbing and grasping abilities are a great adaptation for lemurs as they use these abilities to access their food on trees.   Lemurs use their tails for balance while on branches or to stand on the ground.

            Spider Monkey (New World Monkey/Platyrrhini)

Environment:  Spider monkeys are found in tropical forests of Central and South America.  These are mostly arboreal environments.  They are dependent on fruits, leaves and insects.

Locomotion:  Spider monkeys are diurnal.  They are semibrachiatiors, leapers and use their prehensile tail to suspend from trees (like having a fifth hand).  Spider monkeys rarely come to the ground.

Spider monkeys have adapted to the tree life.  They rarely come to the ground, which is a great defense from predators.  Their long arms and prehensile tail allow for swift movement in top levels of the rainforest trees.  They also use their prehensile tail to hang from trees to feed. 

Baboon (Old World Monkey/Cercopithecidae)

Environment:  Baboons live mostly in Africa, they prefer grassland although some live in tropical forests. They sleep in the trees and are opportunistic eaters.

Locomotion:  Baboons are diurnal.  They are semi-terrestrial and move quadrupedally.   Baboons spend most of their time on the ground but they do climb trees in order to watch for predators, eat and sleep.

Baboons have adapted to their environment partly on the ground as well as the trees.  Although they do not have a prehensile tail to help move around in the trees, they can still climb.  Baboons not only eat from trees they will also eat rodents, birds, and even small mammals such as sheep.

Gibbon (Lesser ape/Hylobatidae)

Environment:  Gibbons live in forests of Southern Asia.  They are arboreal as they rarely see the ground.

Locomotion:  Gibbons primarily live in trees and rarely come to the ground.  Their primary mode of movement is brachiation.  They have long arms and curved hands used to grasp branches.  Gibbons use their extremely long arms for reaching branches and strong legs to propel themselves.  They are also slow quadrumanous climbers.  Gibbons walk on branches and rarely on the ground but they do so with a bipedal locomotion.

Gibbons have significantly adapted to life in the trees.  They are able to move through the trees at unbelievable speeds protecting themselves from predators.  With their long arms they have the ability to swing out and take fruits that might be more difficult for their competition.

Chimpanzee (Great ape/Hominidae)

Environment:  Chimpanzees may be found in Central Africa in savannahs or tropical rain forests.  Chimpanzees eat leaves, fruit, nuts, insects, bird’s eggs and small mammals such as bushpigs or monkeys.  They are arboreal as they spend a lot of their time in trees.

Locomotion:  Chimpanzees are diurnal. They are terrestrial.  Chimpanzees are quadrupedal knuckle-walkers.  Young chimpanzees are known to brachiate.  Chimpanzees walk bipedally on the ground if they are transporting something such as food.  Chimpanzees also have the ability to swing in the trees where they spend most of their time, whether it is sleeping or eating.

Chimpanzees have adapted tremendously to their environment.   They have the ability swing through the trees where they eat and sleep.  They are also able to walk bipedally after capturing their prey, thus freeing the hands of the chimpanzees in order to carry their food. 

     Each one of the primates locomotor traits described above have adapted to their respective environments in significant ways.  Whether it is a tail for balance as seen in the lemurs or a prehensile tail in the spider monkey used as a "fifth hand."  Baboons and Chimpanzees have both adapted to lives in the trees and the ground.  There is also the brachiation used by the gibbons but also seen in spider monkeys.  Bipedalism is seen in both gibbons and chimpanzees.   Each one of these primates have adapted in one way or another, whether it be walking, swinging, hanging, eating or sleeping.  The pressures of their environments has played a substantial role on the expression of physical and behavioral traits.