Human Variation

1. I have selected cold.

This environmental stress can be deadly for humans. Humans need to maintain a certain body temperature to survive, generally 98.6F. It can fluctuate to one degree depending on the individual.   Though, extreme cold can drop the human’s body temperature, which can result in hypothermia. Once the body temperature drops to 94F, it can become very dangerous, especially because once the temperature reaches 94f, the human body temperature drops even more rapidly.

2.

·         Short term adaptation to the cold:

Humans start shivering. Shivering causes the muscles of the human’s body to function, which in short increases temporarily the body heat as a means to deal with the cold.

          

     

·         Facultative adaptation:

Vasoconstriction is “the narrowing of blood vessels to reduce blood flow to the skin. It is an involuntary response to cold and reduces heat loss at the skin’s surface” (textbook).

 

·         Developmental adaptation: because humans living in the cold have the tendency to eat more fat food in order to cope with the cold, the “shape of these human’ bodies will have the tendency to be more round and squat” (assignment).

 

·         Cultural adaptation:

There are many ways humans can deal with the cold. They can wear warmer cloth, use the heater or make a nice fire indoors. Some cultures also drink strong alcohol as a way to increase temporarily body heat. 

     

3. There are many benefits in studying human variation.  First, we understand better the use of the word “race”, which has more to do with human variation than just the color of the skin or nationalities. Second, this information can also be useful to anyone who would like to move to a very cold region. The individual would now know what to expect or how to cope with the cold or people that live in such cold areas.

4. The word “race” has undergone many different meanings. In this specific example though, 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.

Language

Part 1:

I found this experiment very difficult. It is very hard not to communicate vocally when we are able to. Because I could not speak, I really did not have much to “say” and did not even really want to participate in the conversation since I truly couldn’t anyways. No gestures could have helped me express what I wanted to say. Not being able to communicate with words really limits the “meaning” of a communication. No important ideas or deep communication can be expressed.

At first, my partners looked at me in a very weird way, and kept on asking me what was going on with me. My husband told them what was going on. I still played the game. Once they found out, they pretty much stopped talking to me. I might have done that to myself too when I think about it. I guess I did not want to look like a fool. The only time they really talked to me was to offer me some wine or other things. Not being able to communicate with words alters the way people would normally react.  

The culture that has an advantage when it comes to communicating complex ideas is the culture that is able to speak. The problem is that it would be difficult to expand this complex idea with someone who basically cannot talk back. Signs and body movements are just not enough. The spoken culture would probably look down on the non-spoken culture. Not being able to express complex ideas limits the interest that a culture could have with another culture. It could also make it look inferior. People that are deaf are not able to communicate with spoken language. Unless these people have an interpreter, it is really hard to communicate with them. I would say that generally, people who are capable of spoken language will intentionally not interact with a non-speaking person. The non-speaking person will generally be left out and will naturally feel left out. It is very sad.  Spoken language plays an important role in the way people interact with one another.     

Part 2:

I have not been able to use only speech for communicating. Being French, I do use my arms a lot when I talk, as well as facial expressions. I repeated the exercise twice, and succeeded the second time. It was very frustrating though. I had to think about all of my body gestures while talking. It was not natural at all.

They saw that I was not myself. I did not tell them, but they noticed that something was different. That is also because I had to think about not using any part of my body while talking. I felt awkward, and must have looked awkward. What made it more awkward is that these people know how expressive I am.

Many cultures use their hands or facial expressions while talking or even listening. Spoken communication is as important as non-verbal communication. It defines who we are. I could just imagine someone who is giving a speech who cannot use the space or its body to give more sense or power to its speech. The lack of non-verbal communication would affect the overall quality of the speech. Actually, when we take a speech class, we are taught techniques to use non-verbal communication. These techniques are indeed very efficient. Some people master these techniques so well that they actually can become harmful to individuals. Speech is an art.  

Some people such as blinds cannot read body language. There are advantages to not reading body-language. For one, we might not have to worry so much about being judged or misinterpreting a body gesture. Still, it is a great ability to read body gesture as body gesture reveals so much information. Let’s say someone is giving a speech. Analyzing the spectators’ body gestures can give the orator much feedback about its speech. If the spectators seem asleep, the orator should maybe try to change the intonation of its voice or speak louder. It could also reveal that the speech in itself is not very interesting… Body gesture is very informative. It also reveals the state of mind of an individual, which can be a good indicator for another person to want to approach this other person or not. Let’s say that an individual is walking in a foreign country and needs to ask directions. This person is going to try to find another person that seems nice enough to answer to his question. In doing so, he will analyze the other’s person body gesture before selecting the person he will approach. The way someone walks, acts is very important. Body language is so relevant in the way we react with one another.

The Piltdown Man

The Piltdown Man was discovered in 1912 by a workman while he was digging in a gravel pit in a village near Piltdown, in Southern England. This workman gave the piece of the skull he found to Charles Dawson, an amateur archeologist. Charles Dawson then contacted Sir Arthur Smith Woodward, the keeper of Geology at the Natural History Museum, as well as a Frenchman. The three of them formed a digging team with the hope to find more fossils within this area. In September 1912, they found more fragments of the skull and a jawbone. In December 1912, a meeting was held to make the announcement of this recomposed skull. It was also thought that that this skull was “the evidence that England had ancient human fossils. This England’s human ancestor might be the oldest of all: the Piltdowm Man.” Many people believed in this finding; others, had doubts.For one, they thought that the jawbone did not look human, but more like an ape. Furthermore, other ancient human fossils had been discovered, and the Piltdown Man did not match any of them. It comes out that in 1953, this Piltdown Man was proved to be an hoax.    

Humans have faults. In this scenario, jealousy and self-interest were human’s faults. For one, when it comes to Charles Dawson, his findings made him famous. For two, many ancient fossils had been found in Spain, France, Germany, and Africa, but nothing had been found in England. Not only would this Piltdown Man reveal the existence of an early man in England, but this Piltdown Man would also be the “missing link between apes and humans”. 

The dating method is what revealed the Piltdown man as a hoax. In 1949, a fluorine test has been performed on this skull. “By measuring the fluorine content of fossils, scientists could date them”. The results were 100,000 years, which was too modern. The skull had been stained on purpose. Furthermore, they found out that the jaw was the one of an orangutan. With a microscope, scientists found out that “the teeth had simply been flied flat to disguise them. The fossils had been boiled and carefully stained with chemicals. The canine tooth was crudely filed and colored with paint”. The teeth were the ones of a 500 years old chimpanzee This Piltdown Man was nothing but an hoax.

I would not want to remove the human factor from science. Sure, the Piltdown Man was an hoax, and affected the overall image of scientists, but what is more important is the fact that the truth about the Piltdown Man has been revealed because of scientists. Errors are made in science. Theories for example can be revised or adjusted because of other scientists. It took 40 years for scientists for example to prove the forgery of the Piltdown’s Man fossils, but scientists still reached the truth. This is also what makes science challenging and so interesting.

The life lesson is that humans need to seriously examine situations, findings, or theories before they can take things for given. It is not enough to assume that something is true. It needs to be proven. Everything needs to be tested or analyzed.  

Primates

Lemurs:

a. Lemurs are small primates. They live in Madagascar, a large island off the east coast of Africa, and on the nearby Comoros Islands. Many species live in tropical rainforests, but other live in dry forests. There are 5 families of lemur, and about 60 surviving lemur species there. Lemurs vary greatly in size and appearance.

b. Lemurs are social creatures and most of them live in troops. They benefit from living in groups by getting protection, food and mating opportunities. Most of these species are diurnal (are active the day, sleep at night); others are nocturnal. These species are also arboreal, with the exception of the ring-tailed lemur..

Lemur females are dominant. A group of lemurs usually has one dominant female who leads the group, controls their movement, and has first choice of food and mates. When conflicts between groups happen, it’s the females who fight. When it comes to breeding, males sexually mature at the age of 5, while females mature at 4 years old.  

Lemurs are territorial. They mark their territories by rubbing their scent glands into branches, and will fight other rival groups if necessary.

c. The harsh climate factors on the island of Madagascar could explain the evolution of female dominance.

              Image of lemurs 

Spider monkeys:

a. Spider monkeys live in tropical climates, specifically the evergreen forests of Central and South America. They can also be found in Mexico. They live in the upper canopy of trees. The spider monkeys' habitat is disappearing at an alarming rate.  
b. Spider monkeys are social animals. They are diurnal and arboreal. They live in small to medium size groups. At night, they sleep in high trees above the canopy, which ensures their safety when it comes to predators. When it comes to breeding, males sexually mature at the age of 5, while females breed at the age of 4. Spider monkeys breed all year long. Gestation lasts for 226 to 232 days and one baby is born at a time with births occurring in 2 to 4 years interval.   

Males are the philopatric sex. Females have a more active leading role than males. They are said to be better at finding food than males. Finally, unlike other primates, spider monkeys do not spend as much time grooming each other because they do not possess a completely developed thumb. Grooming therefore only occurs between mothers and their offspring.  

c. The relationship between spider monkeys evolved as a response to their eating patterns, which consists largely on seeds. Because their food is seasonal, living in large groups is not favorable.

  

 

Image of spider monkeys

Baboons:               

a. There are 5 species of baboons. Baboons are mainly found in savanna and semiarid regions. Out of the 5 species, 4 species live in savanna.  They mainly live on land, but climb and sleep in trees. The five species of baboon replace each other geographically across the open country of Africa from parts of the Sahara southward.

b. These 5 species of baboon all live in troops numbering from 10 to several hundred. Young male baboons typically disperse from their group of birth as they near adult size and continue to migrate between social groups throughout their lives. Female baboons are the philopatric sex. There is a dominance hierarchy among adult males. Males often fight, whereas females rarely fight. Dominant members of each sex have the first choice of favored foods and mating partners; they also keep order within the troop, chasing and threatening subordinates that are fighting or otherwise causing a disturbance.

“Female baboons have pronounced cyclical changes of the external genitalia. These changes, which include swelling and redness, are associated with estrus, a hormonally initiated period of sexual receptivity in female” (our textbook). Male baboons use the size of the sexual swelling to determine motherly success. It is seen that females with the largest bottoms reached puberty the earliest and gave birth to more offspring.  Males also fought more aggressively over females with larger swelling. The most dominant male will mate with more estrous females than will any other males and thus will father a high proportion of the next generation. After ovulation, the female’s swellings rapidly subside, and she is no longer attractive to the adult males. A single infant is born after a gestation of five to six months. Savanna baboons practice infanticide.

 

              Image of female baboon

Gibbons:

a. Gibbons are small, arboreal apes. They are found in subtropical rainforests of Southeast, South, and East Asia. They are currently found in small populations in China, Laos, Vietnam, Cambodia, Thailand, Bangladesh, India, Myanmar, Malaysia, and Indonesia. They are arboreal and considered to be among the world's greatest acrobats. There are 15 living gibbon species.

b. Gibbons are monogamous. They live in nuclear families consisting of a mated pair and their dependent offspring. They are fully grown and able to reproduce at 12-13 years old. Female gibbons are pregnant for about 7 months and usually have a single baby at a time. Male gibbons are involved in rearing their young. The young then venture out (or are forced out by the same-sex parent) to start a new family group of their own. The family unit occupies a territory. A gibbon family has a territory of about 30 to 50 acres of old-growth rain forest. Each morning upon awakening a family group of gibbons loudly announces its presence in the forest, using a territorial hooting call and menacing gestures. This call warns other gibbons to stay out of their territory (and especially away from the local fruit trees). This noisy display takes 1/2 hour or more every morning and is usually started by the adult female. Both males and females are highly territorial.  

 

                 Image of gibbons

Chimpanzees:

a.       Chimpanzees are part of the ape species. They live in tropical forest and savannas of equatorial Africa from the Gambia in the west to Lake Albert, Lake Victoria, and northwestern Tanzania in the east. They are arboreal.

b.       They are social animals. They live in large communities from 10 to 100 individuals. They are diurnal. The males are dominant over the females and adolescent males. Males are very territorial. They often patrol their territories, and are ready to attack if an intruder arrives. Male Chimpanzees are philopatric and form lifelong bonds within their social groups. Female chimpanzees disperse. They find mates outside their natal group. Chimpanzees practice infanticide. Mating occurs throughout the year. Males are capable of reproduction at the age of 16. First estrus is seen in females at 10 years old and is characterized by anogenital swelling. Female chimpanzees mate with multiple males. Female chimpanzees are also the ones to take care of their young ones. Chimpanzees are very active.

c.   Because chimpanzee’s food is abundant, chimpanzees can live in large groups. Male chimpanzees are therefore really concerned with their reproduction success, which explains their practices of infanticide and their aggression.

       

Image of chimpanzees

Analogies and homologies

1.

Frogs and rabbits share homologies. Frogs are amphibians. They have a short body, have 4 limbs, and do not have any tail. They live on land and in water. Rabbits are small mammals in the family Leporidae. They also have 4 legs, long ears and a short tail. They only live on land.

Although their forelimbs seem different, they share the same set of homologous bones – the humerus, radius, and the ulna, which implies that they share the same common ancestor. 

The function of the forelimbs of the frog serves to steer when the frog is swimming and absorb the shock of landing when the frog is jumping on land. The forelimbs of rabbits also serve to support and balance the boy at rest, as well as to absorb the shocks when hopping.

Rabbits and frogs share the same common ancestor. Both species evolved from a group of dinosaurs known as theropods during the Mesozoic Era.    

         
                     Image of a rabbit
Image of a frog

2. Butterflies and birds share analogies. Butterflies are flying insects, which are very small in size. They have 4 wings, 6 legs, and an antenna. Birds also have wings, but they only have two. Their bodies are covered with feathers. They also have a beak. Although these 2 species possess wings, the anatomy of these two species is very different.

  

 For one, butterflies are insects. Insects are anthropods. Like all insects, they have six jointed legs, 3 body parts, a pair of antennae, compound eyes, and an exoskeleton. The three body parts are the head, thorax, and abdomen. Birds though have an internal skeleton, a central system, and four limbs. Birds are aves. 

The butterfly’s wing is analogous to the wings of the birds because the common ancestor of the butterfly and the bird (a reptile) did not possess wings.    

Insects evolved during the Silurian Period, 438 to 408 mya (long before the dinosaurs appeared), whereas birds evolved from theropods during the Mesozoic era.

             

Image of bird                     Image of  a butterfly





Skeleton of birds

Skeleton of Forelimbs of Frog

          

Analogies and homologies

analogies

Analogies and homologies

Protein Synthesis

CGTATACACCTTGTCTGAACGCAATTAAGAGCTCAGTCTTATCTCGA

Historical Influences on Darwin

1. To me, every scientist influenced Charles Darwin in his work, but I would say that Thomas Malthus was the most influential on Charles Darwin’s development of his theory on Natural Selection.

2. Thomas Malthus contributed the theory of population to the scientific community. According to Introduction to Physical Anthropology, this theory states that “population size increases exponentially while food supplies remain relatively stable. Even though humans can reduce constraints on population size by producing more food, Malthus argued that the lack of resources would always be a constant source of “Misery” and famine for humankind” (Jermaine, pg 31).  This theory, for Thomas Malthus, limited itself to the human population. This discovery helped Darwin developing his theory of Natural selection.

            Link: http://www.buzzle.com/articles/thomas-malthus-theory-of-population.html

3.      Malthus’s theory affected Charles Darwin in many ways. Charles Darwin did not limit Malthus’s theory to just humans; he extended this theory to all living organisms. The point in Charles Darwin’s bullet point that was influenced by Thomas Malthus is: Resources are limited. This, in itself, restricts the nonhuman population by growing too much. Whereas humans can produce more food to survive when population increases, nonhumans are restricted to the resources that Mother Nature offers them, which limits its population from increasing too much.

This principle is very important because it allowed Charles Darwin to understand why certain species continued to survive, while others vanished. In short, only the best-fitted species in relation to their environment or resources would continue to persist, while others would eventually die.

4. I believe that Darwin would have developed his theory of natural selection without the influence of Thomas Malthus. For one, Charles Darwin was passionate about his work and was determined in finding the answers to his questions. He would have found them rather by continuing to observe different species or by thinking about his unsolved questions in relation to Natural Selection. It is also possible that another scientist would have reached the same conclusion than Thomas, which would also have influenced Charles Darwin.
5. The attitude of the church has affected Charles Darwin’s work. For example, although he could have presented his ideas of natural selection in 1844, he published his book entitled “On the origin Of Species” only in 1859. The main problem that Charles Darwin, as many other scientists, had to deal with was that his theory of Natural Selection contradicted the traditional values or beliefs of England.  At that time, “it was  generally accepted that all life on earth had been created by God exactly as it existed in the present, and the belief that life-forms couldn’t and didn’t change came to be known as fixities of species” (Jermain, 25).  It was therefore very dangerous for Charles Darwin to share his views with the public as his discovery, once again, contradicted all of the beliefs of the church.