Human Variation and Race

1. High Altitude is an environmental stress that negatively impacts the survival of humans by disturbing homeostasis. When breathing, in high altitudes, the low air pressure makes it difficult for oxygen to enter the human vascular system, causing oxygen deprivation, also known as hypoxia: hypo, meaning low or little and oxia referring to oxygen. Hypoxia starts with the failure to take on normal physical tasks without exhaustion. This “high altitude sickness” also includes symptoms such as: lack of appetite, vomiting, headaches, distorted vision, fatigue, and difficulty thinking clearly. In some cases, the lungs and brain begin hemorrhaging and causes death within days. Also, due to high altitudes, added stress is placed on lungs, arteries and heart, which increases the risk of heart failure.

2. However, humans have adapted to high altitude stress through short term, facultative, developmental and cultural adaptations:

· Short Term: Our bodies begin adapting to the high altitude by increasing its breathing and heart rates to almost double the norm, even during resting. As the heart pumps harder to increase oxygen to cells, our pulse rates and blood pressure peak. These series of heart modifications are very stressful on the body especially for those with weak hearts.

 

· Facultative: In high altitudes our bodies produce more red blood cells and capillaries in order to efficiently carry more oxygen throughout the body. Our lungs, in turn, increase in size to process that oxygen and carbon dioxide. To enhance transfers of gas, our bodies also increase the vascular network of muscles. This results in successful acclimatization to low oxygen pressure.

· Developmental: Populations are most successful when their ancestors have lived at high altitudes for thousands of years. Natural selection plays a significant role in developmental adaptation for populations to live in high altitudes. Primary solutions for those who live in high mountain areas include: increased production of hemoglobin and increased lung expansions to increase oxygen in blood. Some populations adapt to breathing faster in order to intake more oxygen resulting in broad arteries and capillaries allowing for higher rates of blood flow and greater amounts of oxygen to muscles. A study proved that villagers, who reside at 15,000 feet, have 10 oxygen-processing genes that are not usually found in lowland populations.

· Cultural: There are many cultural adaptations to higher altitudes. Mountain climbers usually use oxygen tanks to aid in breathing in order to achieve peaks that are over 5 miles high. Many athletes, for greater lung expansion and capacity, train in higher altitudes. This physiological change, results in increased fitness levels when competing in lower altitudes.

3. There are many benefits of studying human variation from this perspective across environment clines. For example, if we are headed to Big Bear or Mammoth for a winter trip to the snow, it would be very useful to know that our bodies will be lacking oxygen and might go through hypoxia. This will probably change the way we hike up the hills or maybe change the agenda to allow for more resting time.

4. I don’t think that we would be able to use race to understand the variation of high altitude adaptations because race has no impact on how our bodies adjust to different levels of oxygen. The study of environmental influences on adaptations is a better way to understand human variation than by use of race because humans are unique in their given uses of environmental stresses. It allows for a better comprehension of physical adaptations under certain altitudes, whereas race only pertains to phenotypic characteristics and geographical ancestry.

Language

Part 1:

This week I engaged in a 15 minute conversation where I was not allowed to speak!! This experiment was extremely difficult for me. I am a person who is very verbal, enthusiastic and passionate about expressing my thoughts. With this being said, these 15 minutes felt like an ETERNITY for me! I chose to carry my typical morning conversations with my husband and kids—without the speaking part (of course).  When I began trying to express my thoughts through physical antics, my husband seemed puzzled, then very confused, and finally laughed at me saying, “it was awkward because I couldn’t communicate verbally, which comes natural to us”. My kids were getting very confused they wanted to know why I couldn’t just talk to them instead of acting out my thoughts. When I was using gestures to communicate with my kids it brought me to the feeling of when they were babies: I had to use so many hand gestures and movements to connect with them because that was their “language”. I felt like I was a baby trying to communicate with a parent. After an extensive five minutes, my husband eventually altered his way of communicating with me; using hand gestures and speaking slowly (as if I really did speak another language). I feel that if we represented two different cultures meeting for the first time that I would have had the advantage in communicating complex ideas. I think that the speaking culture would have a “snobby” and maybe even irritated attitude towards the culture that doesn’t use language because they know what they are trying to communicate but all they are getting in response would be antics. Babies and toddlers, everywhere, have difficulty communicating with spoken language and it affects adults and older children that do interact with them.  As adults we try to interact with babies by overly expressing our emotions and speaking slowly and loudly to convey our feelings and words. In the experiment, this is how my husband was trying to convey his thoughts to me while I couldn’t speak. I definitely felt like a baby.

Part 2:

In the second half of the experiment, I engaged in another 15 minute conversation, however this time without any physical signals, vocal intonation or body/facial movements. I could not last the entire 15 minutes! This experiment was very difficult for me because I naturally use a lot of body and facial expressions to communicate. Every two minutes I realized I would raise and lower my voice or smile.  I carried on this rather boring conversation with my husband. He said, “I lost all track of our conversation due to the monotonous tone…it was really, really boring…sorry”. This experiment “speaks” for itself (haha).  Signs are so important to our language and our ability to communicate effectively. These “non-speech language techniques” play a large role in our communication on so many levels; it’s how we read others body language and how we are able to adapt to others emotions and antics while they speak. It pushes our language farther than just words, its feelings, passions, and insights.  There are many people who do, however have difficulty reading body language. I think it might be the way they grew up—maybe they weren’t social or brought up in a manner to think much of body language. I think an environmental condition that might have a benefit to not reading body language would be in the coldest places on Earth; where no one would want to stand in the freezing cold to move their faces or open their arms while speaking, allowing the cold to take hold of them.

Overall, I felt that this experiment reinforces the old saying, “Actions speak louder than words”.

Piltdown Hoax

In the early 1900's, Charles Dawson, an amateur archaeologist, claimed to have found ancient human skull remains while digging in a gravel pit in the small village of Piltdown. His findings fooled scientists for 40 years. With the help of Arthur Woodward and Father Teilhard, Charles Dawson soon became famous. With news that the the first remains of an early-human skull were found, many were skeptical ye, didn't express their doubts.  When The Trio, (Charles Dawson, Arthur Woodward, and Father Teilhard), discovered the second set of remains, the scientific community was ecstatic that the missing link between ape and humans were found. Findings after findings, the trio were becoming famous world wide. After Charles Dawson's death in 1916, the Piltman fossils had stopped being found. In the 1920's, ancient human remains were found in Asia and Africa. After testing, these fossils were dated back to approximately 100,000 years after the Piltdown Man. In contrast, the Asian and African remains were LESS human, and brought up the validity of the Piltdown Man remains. After World War 2, new turning points rose in the scientific community such as Fluorine Dating Testing. In 1949, scientists did fluorine tests on the Piltdown Man and arrived at the conclusion that these remains dated back to only 100,000 years before (relatively young). In 1953, a full scale analysis was done and revealed that the artifacts were stained and some of the fossil was cut with a steel knife after fossilization had occurred. They also revealed that the teeth had been filed down and parts of the jawbone were broken off to secure its real identity, a female orangutan. Although there hasn't been a guilty suspect found, theories link the hoax back to Charles Dawson who found the first and last set of Piltdown Man fossils. His clear motive, as an amateur archaeologist, was fame for his conservative campaign for science. Some people blame Arthur Kieth because he needed proof to finalize his Human Evolution Theory. After the case, more than half a dozen other archaeological findings were found; all forged by Charles Dawson.

Even though scientists are curious, creative and persistent, they do carry human faults. Some human faults that came into play in the Piltdown Hoax were national pride and self interest. These human weaknesses negatively impacted the scientific process because it led The Trio to forge all their findings to become known in the scientific community as well as change the aspect of life and evolution for world.

The positive aspect of the scientific process that was responsible for the revealing of the hoax was the 1949 Fluorine Test. By measuring the fluorine content found in fossils, scientists were able to roughly date them. In 1953, scientists conducted a Full Scale Analysis using microscopes to reveal staining, cutting, and filing.

I don't think its possible to get rid of the "human" factor from science to limit the chance of errors like the Piltdown Hoax. I wouldn't want the "human" factor from science because as humans we are curious and creative. Without such "human" factors, there would be no reason for science. I think the technology we have today gives room for scientists to be human. Technology can test hypothesis and prove of falsify theories and still allows the scientist to "think outside the box", by human nature.

The life lesson that I took from this historical event is not to believe everything, until I analyze it thoroughly, or until it has been scientifically prove and backed with technology. I also learned not to let some human faults determine the outcome of hard work. Fame and pride should not affect the scientific process, however, curiosity and creativeness should.

Locomotor Patterns

a). Lemurs are found only in the tropical areas of the island of Madagascar and the Comoro Islands, primarily in the treetops. As herbivores, lemurs are found eating the forest's plants. Some lemurs, eat flowers, seeds, leaves. Omnivore lemurs, such as the mouse lemur, eat insects, eggs, lizards, as well as plants.

b). Lemurs locomotor pattern is jumping from tree to tree, branch to branch, using their long tails to keep balance. Unlike their other primate relatives, lemurs don't use their tails to grip branches, instead they use their arms and legs and travel the treetops.

c). Lemur's environment have influenced their locomotor adaptation. Because they are usually traveling the treetops quickly, their arms and legs have adapted to the swift movements. Their tails have adapted in a similar way as well; to give balance as they span the rain-forests instead of being used as an extra limb like their close primate relatives.

a). Spider Monkeys are found in the tropical rain forests of South, and Central America as well as Mexico. They find their food primarily in the treetops, eating nuts, spiders, bird eggs, fruits and leaves. Spider monkeys are pretty noisy creatures; they yell and shake trees when there is danger around such as margay cats and even humans.

b). Spider monkeys locomotor pattern is swinging using all five's; arms, legs and their tail! Their elongated fingers and abbreviated thumb helps swing through branches. Their prehensile tails grip branches to allow them a graceful journey through the rain-forest's treetops.

c). The Spider monkey's environment has significantly  influenced their locomotor adaptation. Their prehensile tails are a handy adaptation for eating purposes; hanging from their tails allows them to gather food with both hands. The spider monkeys ability to grip with their fingers and thumbs allow them to get out of danger swiftly and allows them to vigorously shake the branches to scare away prey.

a). Baboons prefer to live in the savanna and other dry climates, however, few are found in the tropical rain-forests. They eat a variety of food. For example, fruits, grasses, roots seeds, small birds and rodents. Sometimes, baboons act as pests for some farmers because they attack their livestock such as sheep and also eat their crops. They spend most of their time on ground but do sleep in trees.

b). Baboons locomotor pattern is walking quadrupedally, meaning on all fours. Because they are semi-terrestrial they stay on the ground during the day but also climb trees to sleep at night. Baboons do not have prehensile tails because it is not needed as much as other primates.

c). Baboons environment plays an important part in shaping their locomotor patters. Unlike its tropical primate relatives, the baboon doesn't have a prehensile tail to use as an extra limb. What for? Those limb-like tails are primarily used for grasping branches to move from treetop to treetop. The baboon, on the other hand, stays on ground sitting upon rocks as well as sitting or sleeping on rough branches in trees.

a). Gibbons are known as lesser apes, due to their small stature. They are primarily found in the tropical and subtropical rain-forests of the South, East and Southeast Asia. As omnivores, gibbons eat flowers, fruits, leaves, insects, spiders, bird eggs and small birds. Gibbons spend most of their lives in trees, and because of their great skill of mobility in the dense treetops, most predators can not catch them.

b). Gibbons locomotor pattern includes brachiating, traveling from tree to tree by swinging under branches with hand over hand motion. Sometimes, gibbons walk upright, bipedally (on 2 feet), on the tree branches. When they are walking on the branches high in the rain-forests, they stretch their arms out to keep balance, like a tightrope walker. The most common locomotion, however, is brachiation, in which they spend 90% of the time doing.

c). The gibbons environment influences it's locomotor patterns.Their long arms, strong shoulders and lightweight have been adapted for means of traveling, which allows the gibbons to spend most of their lives swinging from branch to branch or walking on branches. The gibbons find all their food supply high on the treetops so there is no reason for them to go on ground. When they are on ground, they have the ability to walk upright, which is an adaptation for outrunning predators.

a). Chimpanzees live in social communities found in  African rain-forests, grasslands, and woodlands. They are usually vegetarians, usually eating fruits, plants, and leaves.However, sometimes male chimpanzees consume insects, eggs and meat. Chimpanzees are very intelligent, pleasant and peaceful animals.

b). The chimpanzee's locomotor pattern is mostly walking quadrupedally as well as walking upright. While walking on all fours, the chimpanzee is also called a knuckle walkers, like gorillas. The chimpanzee also has the ability to swing from tree to tree, where they do most of their eating and sleeping.

c). The chimpanzees locomotion has been greatly affected by its environment. Whether they are walking in groups quadrupedally, or swinging from branch to branch, their locomotor ability is always adapting to their needs. These interchangable traits are constantly at work to the chimpanzees advantage.

I believe that the environments plays such a significant role in influencing physical and behavioral traits . All the primates studied are so alike. However their environmental stresses causes them to physically look different from one another as well as act quite differently from each other as well. Some primates have long arms and strong tails to brachiate and even eat at the same time. On the other hand, some primates lack these prehensile tails because its not necessary where they live. The primates adapted how to walk, swing or jump all because of their differing environments. I think that environments play an enormous role in how organisms adapt their common physical and behavioral traits.

Homologies and Analogies

Homologous traits are those that are shared between two different species that have a common ancestor that possessed those traits and then passed it on to the next generations. Two different species that share a homologous trait are the beaver and the elephant.

Beavers are known as one of the largest rodents. As herbivores, they prefer to eat leaves, bark, roots, and aquatic plants. Beavers are famous for re engineering landscapes and transforming unsuitable habitats by building dams. 

Elephants are the largest land dwelling mammal on Earth! Like the beaver, elephants are also herbivores. They like to eat grasses, bamboos, leaves, bark roots, bananas and sugarcane; eating about 300-400 pounds a day.

One homologous trait that both the beaver and the elephant share is that they both have incisor teeth that have been adapted to for different roles.  For example, the beaver uses its strong, chomping, incisor teeth to fell and gnaw through trees.  With their powerful jaws and strong teeth they create dams, massive log, branch and mud structures.  Elephants, on the other hand, use their elongated incisors, called tusks, for larger tasks which include: digging, stripping bark, moving obstacles out of the way, defense, and even attracting mates.

 With close examination, both are a modification of the basic incisor. With time, evolution adapted these animals' incisors to perform different functions. These homologous traits were inherited from a common ancestor who, most likely, had incisor teeth. I think the Moeritherium was that common ancestor. Its teeth suggest that it was a herbivore that ate freshwater plant and dwelled in swamps and rivers. Fossils showed the beginnings of the enlarged incisors (tusks) but no signs of trunks.


Analogous traits are not the result of a common genetic history, but are due to a common environmental pressure that caused both species to develop a similar adaptation to that stress. Two different species that share an analogous trait are the flying squirrel and the sugar glider.

The flying squirrel, found in North America and Asia, are small tree-dwelling creatures with fragile bones. They have large black eyes and round ears. They have soft brown/gray fur with white bellies. The flying squirrels possess a patagium, a flight membrane that extends between their hands and feet. However, these are NOT wings, more like sails, the patagium allows the flying squirrel to glide over 100 ft.


The sugar glider, found in Australia,  is much like the flying squirrels. They have almost the same color fur as well as the fact that they are tree dwelling as well. They are active in the night while they hunt for insects and small vertebrates. Sugar gliders are also named for their sweet tooth and their ability to glide through the air like flying squirrels.


One analogous trait that the flying squirrel and the sugar glider share are their unique ability to glide to treetop to treetop as well as their similar look. However these creatures do have differences; they are found on opposite of the world, sugar gliders is a marsupial and carries its babies in a pouch, whereas the flying squirrel has larger babies and is from the placentals. By studying there genes and other traits, scientists have come to the conclusion that they are probably not that closely related and they have similar features, such as the patagium due to there environmental stresses of getting from one treetop to another.

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Malthus the Mentor

Thomas Malthus

(1766-1835)

Thomas Malthus played the most positive influence over Darwin's development of his theory of Natural selection. Malthus's An Essay on Principle of Population was inspiration to Charles Darwin's discovery of natural selection.

Malthus's contribution to the scientific community was his argument in which limits should be placed on population sizes because eventually food supplies and other important resources will run out. An example of his hypothesis being tested is the current human population approaching 7 billion. Thomas Malthus also inspired Charles Darwin's theory of natural selection. Darwin stated in his autobiography (1876), "In October 1838, that is, fifteen months after I had begun my systematic inquiry, I happened to read for amusement Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on from long- continued observation of the habits of animals and plants, it at once struck me that under these circumstances favorable variations would tend to be preserved, and unfavorable ones to be destroyed. The results of this would be the formation of a new species. Here, then I had at last got a theory by which to work" http://www.ucmp.berkeley.edu/history/malthus.html.

Although Malthus had no interests in species change, he did argue limits to human population. His major point in his essay was "that in nature animal populations increase in numbers when resources are plentiful and/or there aren't many predators" (pg. 34). The points most directly affected by Malthus's work are:

1. All organisms have the potential of reproducing exponentially.
• In Malthus's An essay on the Principle of Population, he explains that for a population to increase, it relies on the the amount of resources available. All organisms do in fact have the potential of reproducing exponentially as long as the food supply remains stable.
2. What is preventing organisms from reproducing at their potential?
• Malthus believed that humans could produce more food to lower the amount of restraints on population sizes. However, Malthus also believed that "the lack of resources would always be a constant source of misery and famine for humankind if our numbers continued to increase" (pg. 34). In this case, the lack of resources would soon be preventing humans from reproducing to our full potential.
3. Resources are limited.
• The most important point Malthus makes is the fact that when the population is limited due to a lack of resources available, there will be a continuous race for those valuable resources. This will be the basis of Charles Darwin's theory of natural selection. Survival of the fittest.

In my opinion, Charles Darwin might have eventually developed his theory on natural selection without the help of Thomas Malthus because he was studying by himself when he found thirteen different finches, all resembling one another, however, slightly adapted to the different environments they were found. However, I also believe that if it weren't for Thomas Malthus's An essay on the Principle of Population,  there would not be a basic foundation for Darwin to form his hypothesis upon.. With this being stated,  Thomas Malthus essays and work played a significant role in influencing Charles Darwin's theory of natural selection.

The attitude of the church, during the 1820's,  viewed  evolution, theories, and scientists as suspicious and associated them with atheism and socialism. The fear that if these ideas were widely popular "the church would crash, the moral fabric of society would be torn apart, and civilized man would return to savagery" (pg. 34). Darwin, being cross to the idea of religion, ended up studying theology. After his graduation Darwin voyaged the world. While in the Galapagos Islands, he studied a species of finches which leads to the publication of his book On the Origin of Species. This will forever change the way we perceive the natural world.