Human Variation & Race

1. Select only ONE of the following environmental stresses: (a) heat, (b) high levels of solar radiation, (c) cold, or (d) high altitude. Discuss specifically how this environmental stress negatively impacts the survival of humans by disturbing homeostasis. (5 pts) 

High altitude is an environmental stressor that can negatively impact the survival of humans by disturbing homeostasis. With the increase in elevation, there is a decrease in atmospheric pressing, meaning that there is less oxygen with every breath you take compared to sea level. Your body will need to work much harder to obtain the oxygen that it needs. If exposed to high altitudes for extended periods of time, you may experience anoxia; which is a lack of sufficient oxygen in your blood.

2. Identify 4 ways in which humans have adapted to this stress, choosing one specific adaptation from each of the different types of adaptations listed above (short term, facultative, developmental and cultural). Include images of the adaptations. (5 pts each/ 20 pts total) 

Short term: Increased breathing and heart rate.

Facultative: Increase of lung size, and number of red blood cells due to acclimation.

Developmental: There are a few populations that habitually live in extremely high elevations. They have evolved and developed several mechanisms for adapting to high altitude. Some of these include a higher birth weight, lung capacity, breathing, and resting metabolism.

Cultural: There are certain cultures in the world that have developed ways of coping with living in high altitudes. People in Tibet and Nepal and other areas in Asia have larger capillaries in order to transport oxygen; they also have acclimated to breathe faster than normal. On the other hand, people in mountainous areas in South America have increased hemoglobin levels as well as lung volume.

3. What are the benefits of studying human variation from this perspective across environmental clines? Can information from explorations like this be useful to help us in any way? Offer one example of how this information can be used in a productive way. (5 pts) 

Studying the effects of high altitude is important for understanding how the human body works. Mountaineers can especially value knowing the effects of altitude when climbing. It can also be helpful to skiers, snowboarders or to anyone who will find him or herself in a high altitude area. Athletes sometimes train in high altitudes to build a greater resistance to fatigue.

4. How would you use race to understand the variation of the adaptations you listed in #2? Explain why the study of environmental influences on adaptations is a better way to understand human variation than by the use of race. (10 pts)

I think using race would only be beneficial to understand how people of similar geographic locations and adaptations have evolved throughout time. It is better to study the environmental factors to avoid generalization and racism. Environmental stressors can cause adaptations in anyone. These adaptions just take time.

Piltdown Hoax

1. Begin by giving a brief synopsis of the Piltdown hoax, including when and where it was found, by whom, and varying affects this had on the scientific community. Also include how the hoax was discovered and the varying responses it received from the scientist(s) involved and in the related fields of human evolution. (5 pts) In the early 1900s, a laborer was digging at Barkham Manor near the village of Piltdown in Sussex. He unearthed a strange piece of skull and gave it to a man named Charles Dawson. Dawson realized that the skull looked like one of a primitive human. He teamed up with Sir Arthur Smith Woodward and Teilhard de Chardin. Together, they found more fragments of the skull and teeth. They also teamed with was a huge controversy until in 1953, it was discovered that it was a jaw of a primate forged with the skull of a human. Thus, The Piltdown hoax is one of the greatest paleoanthropological hoaxes of all time. The hoax ties in with Darwin’s theory of evolution because it created a huge controversy that lasted for over 40 years.

2. Scientists are curious, creative and persistent by nature, but being human, they also have faults. What human faults come into play here in this scenario and how did these faults negatively impact the scientific process? (5 pts) Some of the human faults that were present were nationalist and gendered issues. When Dawson discovered the Piltdown man, he as well as other English scientists automatically considered it an early Englishman. Also, when it was discovered, it was seen as a male, skull when Woodward suggested it was a female. During the time of its discovery, the women’s suffrage movement was going on. So critics saw this as a mockery to the suffrage movement.

3. What positive aspects of the scientific process were responsible for revealing the skull to be a fraud? Be specific about scientific tools, processes or methodologies that were involved in providing accurate information about the Piltdown skull. (5 pts) Some of the positive aspects of the scientific process are tat fluoride tests showed that the skull was purposefully stained and dated back to about 100,000 years ago, which was too recent. Also, tests were able to show that the skull was human while the jaw was from an orangutan which was sabotaged in a way to resemble a human jaw as well as its teeth.

4. Is it possible to remove the “human” factor from science to reduce the chance of errors like this happening again? Would you want to remove the human factor from science? (10 pts) Without the “human factor” we wouldn’t have science. Humans are responsible for questioning the world and fining the means to solve them. I don’t think it is possible to remove the human factor from science.

5. Life Lesson: What lesson can you take from this historical event regarding taking information at face value from unverified sources? (5 pts) A lesson that I learned from this hoax is to always fact check. Nothing can be verified at face value, especially in the scientific community. If you claim something to be real, you must have the evidence for it.

Homology & Analogy

1.     Homologous traits

a.     The two species that share homologous structures are the human arm and a cat leg. Humans, or Homo Sapiens, are from the Hominidae family and the only species of the Homo genus. Humans are a distinct species for their enlarged brains and brain activity. The common cat, or Felis Catus, is from the family Felidae. Species in this family have similar anatomy, which consists of: flexible bodies, quick reflexes, sharp claws and teeth.

b.     The bones that compose the arm of a human and cat are composed of all the same bones: Humerus, radius, ulna, carpal, metacarpal, and phalanges. There are differences in structure between the individual bones such as length, width, and girth. The function of the Human arm is to move and pick things up, while the leg of a cat is to help the cat run, jump, etc. The structures of the bones appear strikingly similar, but function differently due to evolution and the different environments each species live.

c.      Considering the similarity of bone structure between the two species, there must be a common ancestor between the two species. the common ancestor of the human and cat is most likely to have been a land mammal.

d.     

2.     Analogous structures

a.     The two species that have analogous traits are the pectoral fins of a dolphin and shark. Dolphins are from the family Delphinidae and are one of the largest species in the Catacea order, which include marine mammals like whales and other porpoises. Their high intelligence levels as well as their tail fin, dorsal fin, and pectoral fins characterize dolphins from other species. Sharks are from the clade Selachimorpha. There are characterized by their gills, pectoral fins unattached to their head, and a cartilaginous skeleton.

b.     The pectoral fin of both the shark and dolphin serve the same function of aiding the animal when it is swimming. They are also very similar in structure and appearance since both species live in water.

c.      One of the biggest difference is the fact that a dolphins are mammals and sharks are fish. Besides the pectoral fins, sharks and dolphins have some major differences when it comes to anatomy. However, I think the common ancestor of the dolphin and shark did share this analogous trait. It was perhaps a species that lived in the water.

d.     

Week 2

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Week 1

1.     Select one of the five individuals listed above who you would argue had the most influence over Darwin’s development of his theory of Natural selection. This could be a positive or a negative influence.

I strongly believe that Thomas Malthus had the strongest influence on Darwin’s hypothesis on evolution. Malthus wrote “An Essay on the Principle of Population” which influenced Darwin with his discovery of natural selection.

2.     Briefly (but completely) describe the contribution this individual made to the scientific community. You must provide one link to an online source of information besides your textbook.

Malthus’ essay was about the influences that the environment, as well as how natural resources affects human population growth. He stated that the amount of resources stay relatively the same, so the population of humans normally adjust and compete for what is available to them. He also stated that if the human population was not regulated, resources would quickly run out and we would all perish from famine. Darwin took his ideas a step further by applying them to the rest of nature.

http://www.ucmp.berkeley.edu/history/malthus.html

3.     From the bullet point list above (under “How does evolution work?”), identify the point (or points) most directly affected by this individual’s work and thoroughly explain how this point was influenced by your selected individual. Again, this could be a positive effect, meaning Darwin built upon the knowledge this information provided, or a negative effect, meaning that Darwin demonstrated that this individual’s idea(s) were incorrect and the mechanism of natural selection was an alternative explanation.

The point that is most applicable with the ideas of Malthus is: “Resources are limited.” Malthus stated in his essay that without regulation of the size of population, resources will become scarce and famine will consume and destroy mankind. Darwin used this idea to explain is idea of natural selection. Since resources are always limited, species must compete with each other to attain those resources. The weak eventually die out, while the stronger reproduce.

4.     Could Darwin have developed his theory of natural selection without the influence and ideas of this individual? Explain.

I think it is hard to determine whether or not Darwin could have been able to come to his conclusions on natural selection without the contributions of Malthus or any of the other scientists listed. However, I also strongly believe that Malthus' contribution is very significant and more influential on Darwin than anyone else.

5.     How did the attitude of the church affect Darwin and his eventual publication of his book On the Origin of Species?

The church considered anything that seemed against the teaching of God’s word was heresy. Of course the church would have a huge issue with Darwin’s publication, but that didn’t stop him. Although he received a lot of criticism from the church, he equally received praise from the scientific community.