Tuesday, October 14, 2014

Human Variation & Race (Seventh Post)


Human Variation & Race

1. The environmental stress I chose is high altitude. This environmental stress negatively impacts the survival humans, because of its alternating daily extreme climate that often range from hot days to freezing nights and winds are often strong and humidity low, resulting in rapid dehydration. In addition, the air pressure is lower which puts a strain on our bodies.

2. Four ways in which humans have adapted to the stress of high altitude, is:
Short term: Our quick response to high elevation is, an increase in breathing and heart rate, which could as much as double, even while not in motion. Pulse rate and blood pressure go up sharply as our hearts pump harder to get more oxygen to the cells.
Facultative: An example are the Tibetans, who inhale more air with each breath and breathe more rapidly. Tibetans have better oxygenation at birth, enlarged lung volumes throughout life, and a higher capacity for exercise." Additionally, there is an increase in the oxygen carrying blood cells.

Developmental: There is massive modification in the oxygen transport system of the blood, especially molecular changes in the structure and functions hemoglobin. This adaptation is associated with better developmental patterns such as high birth weight, increased lung volumes, increased breathing, and higher resting metabolism.
Cultural: Usually there is the inability to do normal physical activities, such as climbing a short flight of stairs without fatigue. Some solution we have developed are oxygen tanks or some people take medications to help deal with the dizziness or shortness of breath.

3. The benefits of studying human variation from this perspective across environmental clines, is that we can focus on specific climates and conditions and study those adaptions and then compare them to other conditions.  Information from explorations like this can be useful to help us in ways, because we can discover aspects a=that could be used in another way. For example "On returning to sea level after successful acclimatization to high altitude, the body usually has more red blood cells and greater lung expansion capability than needed. Since this provides athletes in endurance sports with a competitive advantage, the U.S. maintains an Olympic training center in the mountains of Colorado. Several other nations also train their athletes at high altitude for this reason. However, the physiological changes that result in increased fitness are short term at low altitude. In a matter of weeks, the body returns to a normal fitness level. "

4. I would use race to understand the variation of the adaptions in #2, by looking at the races that live in high climates, and have for thousands or years, like the Tibetans, Andeans, and Ethiopians. Each of these cultures have adapted in different ways.
The study of environmental influences on adaptions is a better way to understand human variation than by the use of race, because the environment is what leads to adaptions, not race.

Sources:
http://anthro.palomar.edu/adapt/adapt_3.htm

Tuesday, October 7, 2014

Language Experiment (Sixth Post)


Language Experiment

Part 1: No Verbal, Written, or Sign Language
       I found this experiment to be quite difficult pretty early on. I felt silly, like I was playing a game, and I also grew quite frustrated, not knowing how to communicate something that required words. We are so used to talking non-stop, that when we can not, it just feels ridiculous. When my partner was confused I wanted to just tell her what I meant, but I could not.
       My partner in the conversation also had a difficult time, because it was basically a one-sided conversation. They could not really ask anything other than yes or no questions, because how could I really respond to anything else? They made this realization and the format of the conversation changed, the topics were limited and uninteresting. They found the whole situation very confusing and unsure of how to continue the conversation. I can imagine, for my partner, it was like speaking to someone who slightly understood your language but could not speak it at all. This made it a challenge to keep the conversation going for the whole fifteen minutes.
       If my partner and I represent two different cultures meeting for the first time, my partner, who is able to speak has the advantage of communicating complex ideas. The speaking culture would have an irritated attitude towards the culture, me, that does not use symbolic language. In our culture if a person has a disability that effects their ability to speak or even an individual who has a different first language, those of us who can speak well and with ease, tend to speak to the individual in a slow and sometimes disrespectful manor. It can be frustrating for both sides. Another example is in high school I sat next to a girl in Art who was deaf. We always smiled at each other and I could just tell she was a nice person. I had to speak throughout her interpreter, however, as I do not know any sign language, and this was quite frustrating to me. I wanted to get to know her, but since I could not actually ask her the questions, there was a disconnect. I felt like I just could not truly get to know her. 

Part 2: Verbal communication ONLY, no expressions/gestures
       This experiment was difficult to keep a straight face. I could not help but want to laugh several different times, knowing I must look crazy. We did last the whole fifteen minutes, but not without difficulty. In addition, I, like many others, like to use my hands when I talk to put emphasis on items and also to show emotion through facial expressions, which helps define the feeling behind what is being said.
       My partner thought I looked robotic. Speaking in monotone, it was extremely difficult for them to interpret the true meaning behind what was being said. This, again, led to confusion and frustration for her. While it was easier to communicate, it was boring and felt unimportant.
       This experiment really showed me how crucial non-speech language is in communicating. Our tone and facial expression play a huge role in expressing how we feel. We take these for granted, and when those are taken away, meaning can completely be misinterpreted. In a way, this part of the experiment is like texting. When you are texting there is no way of telling the emotion or tone of the message sent. In order for the our message to get across effectively, there needs to be emphasis and emotion involved.I really had to work harder to let my words speak for themselves.
       There are definitely people who have a difficult time reading body language or even your tone. For example, children have a hard time understanding sarcasm. I love being sarcastic, but when I am around children they never seem to understand, and just take what I am saying literally. I then have to explain I was only joking. The adaptive benefit to possessing the ability to read body language is that it allows people to read how someone is feeling, whether they are uncomfortable in a certain setting, or are sad. Really it helps us read their emotions. Some environmental conditions where there might be a benefit to not reading body language is for people who are reserved and quiet. If you ignore their shy behavior and just talk to them you will see they just do not like to be the first one to speak or reach out, but are just as nice. By looking past that, you won't view them as standoffish.

Tuesday, September 23, 2014

Piltdown Hoax (Fifth Post)


Piltdown Hoax

         In 1912 a man, working as a laborer in southeast England, discovered an unusual piece of a skull while digging in the village of Piltdown. He passed it to another man, named Charles Dawson. "Dawson later claimed he noticed that the skull was extremely thick and appeared rather primitive." He gathered a group of men from different fields to begin a further search of the same dig site the laborer found the original piece of skull. They found remains of Stone Age tools and prehistoric animals, but their biggest success was finding "an ape-like jawbone with human-like teeth that seemed to link it to the skull Dawson got from the laborer." At this time the remains of primitive humans had been discovered so far in France, Germany and Asia; none had been found in England. Scientists of England were excited by the idea of being marked as another great county with ancient human fossils. Some forty years pass and new fossils of human ancestors were discovered in Asia and Africa which appeared to look less like humans, but more like apes. These new fossils were in fact older than the Piltdown ones, and this caused a clear conflict in our ancestral timeline. Professor Kenneth Oakley proves the jaw bone to be forged using fluorine analysis. This was a bit of a wake up call for the scientific community. It taught scientists that they need to always retest theories, take a closer look, and to not always completely trust what another scientist puts out.
         Charles Dawson was purely trying to establish credibility, by "discovering" this jaw bone that could have been England's first Neanderthal. He clearly was desperate, his ego got in the way, and he saw it as an opportunity to make a name for himself. The best way of describing Dawson's actions was he wanted to achieve success without having to work for it.As Giles Oakley said in the NOVA Piltdown Man video, "Scientists are no different from other human beings. They're not all dispassionate seekers after truth in some kind of neutral way, unaffected by the pressures that affect non-scientists. Egotism, pride, ambition, rivalry, these things affect even scientific judgments." For England, patriotism played a major role in their initial reaction to Piltdown man. As a country they wanted to feel like a great and important country who is home to our potentially oldest ancestor.
         Professor Kenneth Oakley, of the British Museum, used the method of fluorine analysis in the early 1950s to reveal the truth behind the Piltdown hoax. He did this by showing that a hymn skull was actually a bit older than the jawbone that was in question. Once this was proven, other scientists along with Oakley took a closer look at the bones and found it was the jaw of an orangutan, not a hominin. "The staining on the bones was superficial." When looking at Piltdown man's teeth under the microscopic they appeared to have been filed down, still showing scratch marks. This all lead to one conclusion, "somebody had forged the Piltdown fossils."
         The question "Is it possible to remove the “human” factor from science to reduce the chance of errors like this happening again," stumped me at first. I can not think of a single way that would make removing the human factors from science even possible. Science is studying the world through human observation and experiment. The human factor is inevitable, and therefore emotions and biases will always be present in scientific work. This does not always have to be a negative influence though. You would never want the human factor to be completely removed from science, because personal opinions, can and have lead to important discoveries. Sometimes it is a good idea to trust your hunch, or intuition.
         Taking information at face value from unverified sources can be a risk and I believe should not be 100 percent trusted. One should do research and experiments of their own before just going off what another said. Without having doubts and asking questions, we would not get very far in finding new discoveries.

Wednesday, September 17, 2014

Comparative Primate (Fourth Post)

Comparative Primate  -  Dentition Patterns


Lemurs (Prosimians/Strepsirhini)
  1. "Lemurs live in trees but some large species of them also spend time on the ground. They are only found on the Comoro Islands and Madagascar Islands. They live all over the place rather than in just one particular region. Some Lemurs live in the rain forests but others live in very hot and dry areas. Overgrown forests seem to be the location where the highest number of Lemurs are found."
  2. "They have long, curved, rodent-like incisor teeth. The lemur dentition is heterodont (having multiple tooth morphologies). Lemurs are unusual among primates for their rapid dental development. The toothcomb in lemurs normally consists of six teeth (four incisors and two canines). Lemurs are also dentally precocious at birth, and have their full permanent dentition at weaning."
  3. "In the toothcomb of most lemurs, the bottom incisors and canine teeth are procumbent (face forward rather than up) and finely spaced, thus providing a tool for either grooming or feeding. While fork-marked lemurs use their relatively long toothcomb to cut through tree bark to induce the flow of tree sap. Indri, the largest living lemurs, have teeth that are perfectly adapted for shearing leaves and crushing seeds. "
Spider Monkey (New World Monkey/Platyrrhini) 
  1. Spider monkeys live in the tropical rain forests of Central and South America and occur as far north as Mexico. These monkeys spend most of their time aloft. These New World primates gather in groups of up to two- or three-dozen animals. At night, these groups split up into smaller sleeping parties of a half dozen or fewer. Foraging also occurs in smaller groups, and is usually most intense early in the day. Spider monkeys find food in the treetops and feast on nuts, fruits, leaves, bird eggs, and spiders.
  2. Spider monkeys have large incisors and small molars with low rounded cusps.
  3. The larger incisors and small molars of the spider monkey reflect the largely frugivorous, mainly fruits, diet.
Baboon (Old World Monkey/Cercopithecidae) 
  1. All five different species of baboons live in Africa or Arabia. Baboons generally prefer savanna and other semi-arid habitats, though a few live in tropical forests. They climb trees to sleep, eat, or look out for trouble. They spend much of their time on the ground. Baboons are opportunistic eaters. They eat fruits, grasses, seeds, bark, and roots, but also have a taste for meat. They eat birds, rodents, and even the young of larger mammals, such as antelopes and sheep.
  2. They have heavy, powerful jaws with sharp canine teeth. Males can have canine teeth as long as 2 inches.
  3. The long canine teeth you see on a male baboon are adaptations for male-male competition; males use these teeth to fight with other males and gain access to females. More commonly, males do not even have to use their teeth: they simply display them to other males in an open-mouthed threat or yawn, which serves as a signal to other males to stay away.
Gibbon (Lesser ape/Hylobatidae) 
  1. These acrobatic mammals, endemic to the dense forests of southern Asia, ranging from northeastern India to southern China to Borneo, are perfectly adapted to life in the trees and rarely descend to the ground.
  2. They have teeth that are downward in shape. Their teeth also are similar to the great apes, with molars that are bunodont and lack lophs. The upper molars usually have a cingulum, which is sometimes large. The canines are prominent but not sexually dimorphic. 
  3. The molars are sharp which can help them for fighting off predators and for food. 
Chimpanzee (Great ape/Hominidae) 
  1. Wild chimpanzees are only found in Africa, where they inhabit 22 African countries, from the west coast of the continent to as far east as Tanzania. Chimps live in tropical rainforests of what used to be the equatorial forest belt of Africa. Some chimps are able to move into quite arid areas, such as southwest Tanzania and Senegal, where they are found in secondary forests, open woodlands, bamboo forests, swamp forests, and even open savannah. Chimps seldom venture far away from forests, except when moving from one forest patch to another; They spend considerable time in trees, where they sleep, forage and socialize.
  2. Apes (humans included) all have the same dentition pattern. They also have baby teeth, known as their “milk teeth,” that they loose when the adult teeth come in.
    One difference between our dentition is that though non-human apes have canines in the same place as humans, their canines are much larger than ours.
  3. "What we know about diet probably doesn’t explain why they would have almost carnivore-sized canines. Since they eat mostly fruit, leaves, and other plant items as well as sometimes small mammal meat. Still, even that small amount of meat wouldn’t be the reason for why non-human apes have such large canines. What other purpose can teeth serve if not to chew up food? Threat. Certainly large canines are quite intimidating, and can serve as a warning to enemies to stay back, or else you could get bit and it’ll hurt!"

In conclusion, each of these primates have similar teeth structures with the large canine's being the outlining pattern. A fruit being a common meal, their teeth have developed to help with seeds and the skin of fruits. As said on the example Primate website, "All primates have essentially the same kinds of specialized mammalian teeth adapted to eating a wide variety of foods." Depending on the environment and the type of food that is available to them, certain teeth are put to better use then others.


Sources:

Thursday, September 11, 2014

Analogy and Homology Traits (Third post)


Analogy and Homology Traits


1. Homologous traits
  
a.The two different species that share the homologous trait are the common bird and the                          arctic fox who has similar bones in their legs as a bird does in its wings. 
   b. The 
bones look quite similar, but the fox has them in its legs, while birds have them in their wings. Therefore the fox uses them to run, and a bird uses them to fly. Both are of a similar exertion, regardless of their placement, because it is what pushes each of them forward. 
   c. The fox shares a common ancestor with all organisms, but is more closely related to vertebrates like reptiles, amphibians and birds.
   d.

2. Analogous traits
   a. The two different species that share the analogous trait are the domestic dog and the bear, who both have long snouts, or sometimes called, muzzles.
   b. Bears and dogs both have the same long muzzle that look remarkably similar. These help them chew and tear up meat when eating. The long snout gives them a better sense of smell, which is crucial for hunting prey. In addition, for example, in polar bears the long snout helps warm the inhaled air.
   c. Dogs and bears are both part of the Caniformia (Canoidea) suborder, which includes the "dog-like" carnivores (order Carnivora), like bears, dogs, etc. Caniforms first appeared as tree-climbing, superficially marten-like carnivores in the Eocene around 42 million years ago.
        Bears and dogs are different enough to be granted their own separate families though, but do share a common ancestor along way back.  There once was even an animal called a Bear Dog. 
   d.




Thursday, September 4, 2014

Thursday, August 28, 2014

Charles Darwin's Influencers (First Post)



Charles Darwin's Influencers                                                                                                              by Alexandra Jones

I believe, of the five individuals listed, Thomas Malthus' work and contributions influenced and shaped Charles Darwin's work the most. Since Malthus inspired both Darwin and Alfred Russel Wallace, who both later came to the same conclusions on their own about natural selection, Malthus is the clear connection.

Thomas Malthus' writings, An Essay on the Principle of Population, brought up that although animal populations consistently increase in numbers, the supply of food and water seem to stay roughly the same. Malthus was in fact unconcerned with changes in species, but focused on the "limits to human population growth" (31). He not only shed light on these issues, but he also thought of some solutions. He believed "populations needed to stay within appropriate limits by either raising the death rate or lowering the birth rate."
"Even though Malthus was not a scientist, he was an economist and understood populations and their growth or decline. Charles Darwin was fascinated by the idea that the human population was growing faster than food production could sustain." 
The points most directly affected by Malthus' work are: All organisms have the potential of reproducing exponentiallyMalthus realized some animals (offspring included) had to die off or there would not be enough food, etc. for all of them. Resources are limitedpart of Malthus' work included, populations grew faster than food supplies could sustain. Who gets better access to these limited resourcesthis brings up the idea of competition, it is not a matter of random but of who is stronger, faster etc.

I believe Malthus' influence on Darwin was a crucial part of what helped lead him to the idea of natural selection. This is due to the fact that the idea of competition was first brought up by Malthus.
"...when population size is limited by resource availability, there is constant competition...Competition among individuals is the ultimate key to understanding natural selection" (32).
The attitude of the church caused Darwin to be leery about publishing his work, knowing he would receive backlash. Any thought of evolution was viewed as going against Christianity and the Church. In addition, "He was deeply troubled that his wife, Emma, saw his ideas as running counter to her strong religious convictions" (37). These worries led the publication of his book On the Origin of Species to take longer. 


Sources:
http://evolution.about.com/od/Darwin/tp/People-Who-Influenced-Charles-Darwin.htm
http://evolution.about.com/od/scientists/p/Thomas-Malthus.htm