Human Variation

            The cold can negatively impact the survival of humans and disturbs our bodies’ homeostasis by dropping our core body temperature. A normally person’s body temperature is 98.6 degrees, with some variations because of body size. When a person’s core body temperature drops below 94 degrees, hypothermia begins to occur. Hypothermia is when your body is losing heat faster than it can produce it. This can result in death if the temperature continues to drop because your heat, nervous system, and organs cannot function properly.

            A developmental adaptation that occurs is the evolution of more compact and round bodies of people who live in colder weather. Less surface area is exposed and individuals are therefore better able to retain heat. People also wear heavier more insulated clothing which is a cultural adaptation. A short term adaptation is the narrowing of blood vessels near the skin surface to store more body heat by limiting blood flow. Lastly, a facultative adaptation is the eating of high calorie foods. This intake leads to an increased basal metabolic rate, which creates extra body heat.

            The benefit of studying human variation from this perspective is understanding that many traits develop as a result of our environment that we live in, not because of our race. For example, many people would say the Eskimo “race” tends to be rounder. This is not because of their race, but exists as a result of the cold climate they live in. Their excess body weight in their torso creates more heat for them and has developed as a way to better survive and adapt.  This information could be used to educate ignorant people who stereotype races and their traits based off their skin color.

            Human variation is better than using race as a measure of traits because it reveals the true underlying cause for why a trait may have developed. As previously mentioned, Eskimos tend to be more overweight as a result of their adaptation to a colder climate. The wearing of warmer, heavier clothes, for instance, can be attributed to many “races”, but not because their race genetically predisposes them to this. They need to wear this clothing in order to survive in their environment.

            

Language

            I found this experiment to be much more difficult than the second experiment. I was allowed to make facial expressions and use my body in order to describe my emotions, but I was very limited in my ability to give a substantial response. My partner in the conversation was almost frustrated in a sense because I was not really answering or contributing much to the conversation. It was much more of a one way street. He ended up asking me much more direct and simple questions, ones that I could answer with a yes or no. The conversation also took on a much slower pace, since he had to spend a lot of time trying to understand what I was saying.

If my partner and I were representing two different cultures, then he would have the advantage as the speaking culture in expressing complex ideas. He has the language capacity to express his culture’s behaviors and traditions in great detail, whereas I could only imitate briefly. The speaking culture would possibly have a superior attitude toward the other culture because they would feel more advanced since they know how to speak. They might even believe the other culture is stupid. Deaf people are one subset of individuals who do not use spoken language and I believe they are treated differently as a result. Speaking people will often whisper around deaf people or treat them as though they are inferior. This behavior is extremely ignorant since they can communicate just as effectively as we can.

            This experiment was easier than the first one, but still very difficult to accomplish. My partners were having trouble understanding my emotions and reactions to what they were saying. I was not showing any facial expressions and I used a very monotonous tone in my voice, thus masking any feelings I had about the conversation. We were able to have a fully functioning conversation, but it was very serious and my partners seemed confused about my attitude. They even asked me a few times how something made me feel which was odd to hear.

This experiment reveals the importance of body movements, gestures, and facial expressions in our language. They communicate something much deeper than words, and are a key part of forming connections with people. They can help us express our feelings, tell if someone is uncomfortable or lying, show sympathy, and so on. Unfortunately, there are some people who are unable to read body language. Often times, individuals with Asperger syndrome cannot read body language and they take what someone says at face value, without reading in to it. For example, if someone was being sarcastic, they would not catch on to this. The advantage to being able to read body language, as previously mentioned, might be when someone is being sarcastic with you, you are able to recognize this and play along. Or if someone has just been hurt what something you have said, but they say “I’m okay”, you can read their body language and facial expression and see they are clearly not okay. 

Piltdown Hoax

The Piltdown hoax occurred in 1912 in Piltdown, England, when amateur archaeologist Charles Dawson was digging in a gravel pit. He then supposedly discovered a piece of ancient human skull. The top of the skull looked like a modern human’s, but the jaw was very similar to an apes. He then invited Arthur Woodward to Piltdown, and since Woodward was a well-established and respected archaeologist, the finding was deemed revolutionary to the theory of human evolution. The people of England were enthusiastic and thrilled that their country too had ancient human fossils. It supported the idea that many scientists believed that human evolution began with the brain, and upright walking came later. We now know this is incorrect, as upright walking came first, then the larger brain. For forty years the hoax went undiscovered and scientists went on following this model of human evolution. However, new skulls were then being found in Asia and Africa which appeared to look more like apes, and less like humans. These fossils were much older than the Piltdown findings, and this conflicted greatly with the timeline of human evolution. Then, scientists began testing the fluorine content of fossils to calculate their age. It was learned that the fossils Dawson found were not more than 100,000 years old. Additionally, closer analysis showed intentional staining of the fossils and filing down of the teeth to make them look more human. The hoax setback our understanding of human evolution, but it also taught scientists to test evidence more thoroughly.

            Many human faults came into play with the Piltdown hoax. The biggest issue was the egos involved in the fake discovery. Regardless of who committed the falsification, one of the men involved let their pride takeover and wanted to achieve success without having to work for it. He wanted to receive notoriety for his discovery so he could feel important in his field. Furthermore, nationality and patriotism comes into play, since many people of England believed this information at face value simply because they wanted their country to have ancient human fossils like Asia, Africa, and other European countries. Furthermore, at the time, these Piltdown fossils were thought to be the oldest yet, once again inflating the pride of English scientists.

            By measuring the fluorine content of the fossils, scientists were able to determine the approximate age of the ancient skulls. They could also see that a steel knife was used to cut the remains, along with artificial staining. When they examined the remains under a microscope, they could see scratch marks on the teeth, indicating the teeth had been filed down.

            I do not think it is possible to remove the human factor from science. We can take as many steps as possible to reduce its presence in science, but it can never be wholly eliminated. We are human beings with flaws and emotions, and we can never be completely objective. However, I do not always think this is a bad thing because it can lead to improvements in evidence testing (as it did with the Piltdown hoax), and it leads to new innovations and opinions every day in science.

            In all aspects of life, but especially when it comes to scientific information, I think it is extremely important to research and test evidence in order to verify its validity. If we simply accept what is told to us without questioning it, then we will miss out on the truth of many situations. We need to question and doubt in order to learn new ideas. 

Comparative Primate Traits

Lemurs are found only on the island of Madagascar and in some close by islands on the east coast of Africa. Madagascar is an extreme ecological niche for these lemurs to live in, as they have a rain forest in the east and the west is very dry. They also experience severe droughts followed by flooding, which causes very little plant growth. Most lemurs are very social and live in groups of 10-15, comprised of males and females of all ages. Only nocturnal lemurs are solitary. Lemurs are seasonal breeders and usually only breed for three weeks every year. They must time their breeding to deal with the food availability and harsh weather of Madagascar. They use vocal pitches to communicate with one another. Since lemurs are the only nonhuman primate living on Madagascar, they have no competition from other primates to threaten them. Therefore, they have been free to develop many different social groups, some solitary, some paired, and some larger groups. However, the island’s extremities have caused them to alter when they will mate, which only gives them a small window of time to reproduce.

Spider monkeys live in the tropical rain forests of Central and South America. They are arboreal, meaning they live in trees, and they deal with high temperatures and high amounts of rainfall. Spider monkeys are very social and live in groups of two to three dozen. During the day, they split into smaller groups to forage, and they do the same at night when they sleep. They can communicate with another through gestures and different calls and screeches. When a female is ready to reproduce she chooses her male and they sniff one another to make sure they are ready for copulation. A female spider monkey usually has one baby every three to four years. Since spider monkeys live in tropical rainforests, they are threatened by many predators, including snakes, leopards, and tigers. As a result, spider monkeys adapted to their environment by forming such large social groups. In this way, they provide support from one another and are able to communicate with each other in order to avoid danger.

Baboons live throughout sub-Saharan Africa and live in many types of regions, including savannas, mountains, tropical forests, and deserts. Baboons are terrestrial and spend most of their time on the ground. Their group sizes can range from 10-200, which is primarily due to which type of environment they live in. Baboons that live in savannas have much larger groups, as opposed to desert baboons. Females start reproduction by putting her swollen butt toward a male baboon. After six months, the baboon gives birth to one baboon. Baboons adapted to their environment by grouping together as much as they can to find food and water supplies, especially those that live in the desert.

Gibbons live in Southeast Asia, islands, and China and live in tropical rainforests. Gibbons are arboreal and are the fastest at swinging from tree branches. Their social groups usually include a male, a female, and their offspring. Most gibbons are monogamous and extremely territorial. They protect their territory by singing every morning as a warning to predators and other gibbons. They have adapted to their environment by doing so, since there are many predators that face the gibbons.     

Chimpanzees live in central Africa in tropical rainforests. However, with deforestation, many chimpanzees are now forced to find new areas to live. Chimps live in large communities ranging from 10-100, and often the males of the group form a close bond. Together, they protect and defend their territory. This is especially important because of deforestation. Chimps are now even more vulnerable to attack, since they spend most of their time in trees sleeping and eating. Chimpanzees do not have seasons of mating; they mate throughout the year when the female is receptive. Chimps have adapted to their environment by forming large groups that protect one another and forage together. 

Ultimately, I have found the environment that a primate lives in has a huge affect on their behaviors. I also noticed that it had a very similar effect on primates, with most primates forming large groups in order to protect one another from predators and other threats. Additionally, I discovered that mating for some primates was dependent on food supplies and overall conditions. 

Homology and Analogy

Analogous Traits

a) Sharks are cartilaginous fish and typically live in very deep waters of the ocean. They have gills and breathe by extracting oxygen from the water. They are carnivorous hunters and spend most of their time searching for food. Dolphins are marine mammals and generally live in shallow waters. They have lungs and nurse their young, and they are also carnivores.

b) Sharks and dolphins both possess the analogous trait of dorsal fins and pectoral fins. They need these fins in order to maintain stability while swimming with agility. Dorsal fins sit on top of both of the animals and help keep them upright. Pectoral fins are located on the sides and help them turn and stop. Both the animals had to develop these fins because they needed them in order to swiftly swim, not because their ancestors shared this common trait.

c) No, the common ancestor of sharks and dolphins could not have shared this trait. We know this because sharks are fish, whereas dolphins are descended from mammals. As a result, their common ancestor could not have had this trait.

Homologous Traits

a) Crocodiles are aquatic reptiles that are carnivorous and are adept swimmers. They have a streamlined body and four limbs. Mice are small rodents with tiny ears and long tails. They have four limbs and an extremely good sense of hearing.

b) The homologous trait these two share in common is four limbs. The same bones support both animals, but they are differently shaped. Crocodiles implement a "high walk" where they lift their entire body trunk and at least the anterior half of their tail clear of the ground. Crocodiles also use their limbs to help them swim. Mice use all four limbs to walk and run. They stand on their hind legs a lot more than crocodiles do, mainly to eat. Ultimately, even though they share the same limbs, they use them for differently and they are shaped differently.

c) The ancestor of crocodile and mice are tetrapods, which are animals that are vertebrates. We know that tetrapods developed limbs because we can see these in fossil records.

Protein Synthesis

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Theory of Natural Selection

1. Thomas Malthus

2. Thomas Malthus was an economist who argued that as the population increased, the food supply and resources would not be able to keep up. Eventually, the population would level itself out due to famine and starvation. He argued that the only solutions were to raise the date rate or lower the birth rate.

http://www.bbc.co.uk/history/historic_figures/malthus_thomas.shtml

3. Malthus's work touches on multiple points, but most importantly are: resources are limited and organisms with better access to resources will be more successful in their reproductive efforts. Malthus proposed that the population was increasing at a rate that was too fast for the planet to sustain. This directly relates to the idea that resources are limited. Organisms with access to the most resources, however, have the best chance to reproduce and survive. This helped shape Darwin's idea that only animals with the best traits would survive and be able to pass down these advantageous characteristics. As a result, the population has now been changed and Darwin's theory of natural selection has taken place.

4. No, Darwin could not have developed his theory of natural selection without the influence of Thomas Malthus. Malthus provided the basis for Darwin's theory of natural selection. If a organism reproduces exponentially, the resources will eventually run out, and thus "survival of the fittest" will ensue. Malthus is the reason the idea that our planet could not sustain unlimited reproduction came to light. Without him, the notion that sources would deplete and famine and starvation would weed out the weaker organisms would not have been discussed. As a result, Darwin was able to create his theory of natural selection.

5. Charles Darwin was attacked by the church for his theory of natural selection. It went against the word of the bible and claimed that God was not in control of our world's organisms. Darwin's theory led to the implication that organisms were not created by God, but rather had evolved from other organisms and this was a direct conflict for many believers.