Tuesday, October 11, 2011

Human Variation

I chose to do my blog on high altitude and how humans adapt to compensate for the thinner air.  High altitudes itself has about the same percentage of oxygen in the air as sea level air does.  However, the air pressure at higher altitudes makes it harder for the oxygen to pass through selective permeable membranes in the lungs.  This causes the body to go into a state of hypoxia which is a term for lack of oxygen.

Short term adaptations

An initial response to higher altitudes is the body begins to start breathing faster and the heart starts working faster as well. This adaptation is to try and pump the oxygen throughout the bloodstream. At the same time, the body doesn't digest food as fast either to allow for the body to work harder on pumping oxygen rich blood throughout the body.

Facultative adaptations

Over a longer period of time, the body will begin to acclimatize to the higher altitude.  More capillaries and red blood cells are created to compensate for the smaller amounts of oxygen in the body.  This allows for the oxygen to spread faster throughout the body.  The lungs also expand in response to the lesser air pressure in the higher altitudes.

Developmental Adaptations

South Americans and Tibetans are two cultures that live and have lived in high altitudes for thousands of years.  The South Americans that inhabit the Andes Mountains produce more hemoglobin to carry oxygen in their blood.  The Tibetans breather faster and have larger arteries to allow for more blood flow.

Cultural Adaptations

It is believed that humans first started inhabiting higher altitudes roughtly 10,000 years ago.  These people were hunter gatherers and it is thought they settled here due to the warming climate after the Ice Age. After the ice sheets melted away in the high altitudes, vast regions were found where vegetation could be grown.  The early human populations also were able to keep warm with fire and and warmer clothing created from the fur of various animals that lived in the mountain.

In the case of studying human variation of environmental stresses, it was interesting to read that the Andean people and Tibetan people were able to adapt in different ways to the higher altitudes. A third population, the people of Ethiopia that live in higher plateaus, offer no difference than to the people of lower and yet are able to live there perfectly fine.  This helps in the evolution in regards to how humans adapt.  Why is it that one culture adapted to the same stress and another culture was able to do it completely different? Why is there another population that has no significant difference in genetic makeup or phenotypic expression that would explain why they are able to live at higher elevations.  These are all questions that have scientists exploring how and when the effects of evolution took place in these populations.

I'm not sure how you would use race to explain human variation.  Race includes a specific group of people that do not all live in the same way.  At least with environmental stress studies, the populations involved all live their life in a similar fashion.  It is easier to understand why people that live in hotter climates survive better where they are located than if they were in a colder climate.  Mountain people are better suited to live in mountains than your coastal populations would be.  Race isn't specific enough to determine a lifestyle from them.

Tuesday, October 4, 2011

Week 7 Assignment

     This assignment was somewhat easy, yet difficult at the same time.  I can't say spending a half hour of my day not saying anything was very difficult.  However, getting my g/f to understand what i needed or was trying to say was an uphill battle to say the least.

     Animation was the key to her even having the slightest clue.  I approached her about this assignment and she started laughing but was interested at the same time.  I think she quickly became frustrated as I am not a charades champion. I used pointing a lot and grunting to emphasize.  I can tell by the looks she gave me she was getting to the point where she couldn't wait for it to be over.  She likened the experience to hanging out with her baby niece.  After I thought about it, i guess that is what it is like.  The baby has no notion of spoken language but you usually know or can guess what they want or need.  Through trial and error, you learn the habits of a baby and what sounds refer to what.

     I would say expressing complex ideas is only exhibited through spoken language.  It is the quickest way to know what someone is thinking.  The attitudes of people that can speak often are very arrogant.  Spoken language is seen as a sign of intelligence and people that aren't able to speak are often called "dumb" or other derrogatory terms.  The fact they are able to label people with words that they aren't aware of is arrogance within itself.  People that can speak either speak down to people that can't speak or try to be very helpful.  It usually takes a person to warm up to a person that is different in the fact that they can't speak.  My girlfriend has a brother with Down's Syndrome as well as autism and it can be very difficult to understand what he is saying.  You either just answer with a simple "yes" or "no" sometimes just to move on. Other times make a huge effort just to listen to him and figure out what he's trying to say.  Making it increasingly difficult is he understands me perfect.

Part 2

     I was able to make it the entire 15 minutes because I thought I had no choice but it wasn't difficult either.  My wonderful girlfriend of mine doesn't like cheaters so I had my face covered by a paper bag to prevent any facial gestures.
     It was interesting to note that she was really more frustrated with the spoken part of the assignment with no emotion attached to my voice.  It gives off the impression that I'm not interested in what I'm saying.  Although she knew it was part of the assignment, she got turned off from wanting to talk to me because it felt like a one sided conversation.
     I never realized how much people use their hands when they speak. Often, the hands are good just to capture someone's attention.  They focus on the movement and are able to pay attention to you.  That has some truth behind it because I can't listen to talk radio, but I can watch it on TV when they do the live feeds of radio station.
     Many people, including I, have difficulty reading body language.  I'm not able to capture the slight and subtle movements that clue me in to what someone is thinking. I can't even clue in on the obvious signs that show what someone is trying to emphasize.  People that are able to read body language get so much more information out of an individual.  People can recognize passion from someone that speaks about something they actually care about and they can recognize insignificance when someone is continuously talking about something they have no feelings for.  A situation that is misunderstood is commonly caused by a misinterpretation of body language.  I am not able to think of a situation that i can relate this too.  It would be the equivalent of someone asking me a question I may or may not care about and them assuming one over the other based on something I did that persuaded them to believe on one side.

Tuesday, September 20, 2011

The Piltdown Hoax

1. The Piltdown man is an infamous hoax that is believed to have been conceived by Charles Dawson. Charles Dawson was an amateur at the time of the discovery in a small English town of Piltdown.  Dawson made discoveries of skull fragments in a gravel pit in Piltdown. The overall response from other scientists was that the the Piltdown man skull was a forgery and that it included bone fragments of a human cranium and an ape's jaw.

2. Dawson's ambition and greed paved way for this forgery to happen.  He made up a new species from existing  species' fossils and made it his own.  Same can be said of the scientist, Dr. Arhur Keith, who wanted to support his own idea of the evolution of the human. He saw Piltdown man as a way to confirm his own ideologies and was set on doing everything he could to confirm it.  This would greatly skew the scientific process as evidenced by the many different results from testing the same bone fragments that was down by scientists.

3. Positive aspects that can be taken from the scientific process was the other scientists willing to retest the samples and see if they could come up with the same results as Dawson. Scientists were able to date the fossils with a method measuring the fluorine content in the fossils.  The fossils proved to be roughly only a hundred years old and that number easily put to rest of an ancient human ancestor thought to be a million years old. They were also able to use a microscope and find grooves in the teeth that would suggest the teeth were filed down to a desired wear pattern of a human from an orangutan jaw and teeth fossil. The fossils were stained and manipulated to removed obvious signs of the origins of the fossils.

4. As long as humans are using the scientific process, I would imagine it being extremely difficult to remove the human element from it.  Every scientist has a subliminal bias and way to view the evidence in a way most beneficial to them.  I wouldn't want to remove the human factor from science because then science wouldn't be there.  Most discoveries are done by accident and are usually done in a fashion similar to see if they can disprove or support a theory with new tests.  Humans will be needed to study science to help create a better understanding of how things work.

5.  You learn that you must do your own testing to and research to reassure the facts.  Taking the word of somebody online that tells a story one way is often not told in a truthful manner. You hear all the time about journalists taking comments out of context and twisting the words into a way of a negative connotation.  Celebrities are constantly subject to this practice and us as the readers have no way to know the actual context of the interview.  Until the person confirms or denies that is how they said  and meant something, as a reader we are subject to just know what's been said.

Wednesday, September 14, 2011

Primate Order: Dentition Patterns

Lemurs

  1. Lemurs are native to the island of Madagascar off the southeastern coast of Africa.  Madagascar is very hot, humid and known to have cyclone seasons due to the winds that come in from the east. 
  2. The dentition pattern of the lemur is that of a six-tooth teethcomb with 2 canine like premolars towards the back.
  3. The toothcomb allows for the lemurs to groom each other and is also used for shearing leaves and eating into the bark of trees to get into the sap portion of the trees in the region it lives.

Spider Monkey

  1. Spider Monkeys are prevalent in the Southern Mexico to South American rainforests.  The rain forests bear lots of fruit, the main food source for the Spider monkey.
  2. The teeth of a spider monkey jut out from its mouth.
  3. The way the teeth go outward in a slant helps the spider monkey in devouring fruits from the rain forest in which it lives. 

Baboon

  1. Baboons are found in African and Arabian savannahs and woodlands.  They are able to adapt to any land as long as there is a water source and a safe place to sleep such as a tall tree or a cliff side.
  2. Baboons are known for their very long canine teeth. This is due to the fact that baboons actually have a fair amount of meat in their diet ranging from fish, to even small antelopes.
  3. The longer teeth allow the baboon to bite into and kill smaller animals to eat meat.  This helps in the savannahs where there isn't as much vegetation to sustain a proper diet for the baboons.  Although a baboon's primary source of food is vegetation, it also eats more meat than most primates do.

Gibbon

  1. Gibbons are native to the northeastern rain forests of India into Indonesia and Southern China.
  2. Gibbons have small jaws with long canine teeth, similar to the baboon.
  3. Gibbons have the long teeth in helping them with the small portion of meat they do eat in their diet.  They prefer however to eat lots of fruit, especially fruits high in sugar such as figs.  The smaller jaw helps with the biting into the fruit.

Chimpanzee

  1. Chimpanzees are found in the forests of west and central Africa.
  2. Chimpanzees have the same outward jutting jaw as the Spider Monkey that helps in the fruit eating diet.  They also have the longer canine teeth but are not known to be meat eaters.They also have a thinner enamel than other primates to help them form sharper teeth they need to tear through leaves and fruit that they eat.
  3. The jaw is the most relevant of the teeth of the chimp as it offers the best reason for eating fruit. The thinner enamel was slo interesting in knowing it allows for sharper teeth to help tear through the leaves of their secondary food source. 

Having looked at the dentition patterns of all the primates covered, it was interesting to see the slight changes the primates have gone through.  The fruit eaters have the jaw that juts out that allows for bigger bites of the fruit. The long canine teeth of the baboon and gibbon that help with their carnivorous habits, and the teethcomb of the lemur that allows them to effectively groom each other and allows for them to bite into the trees for the tree sap they also like to eat.  The overall structure of the dentition patterns of the primates are all very similar with very acute differences that benefit the species in its own unique way. It would seem since forests are the main place of habitat for primates, that environment didn't heavily figure in their adapted teeth.  Many of the functions of the teeth were to eat fruit from the forests with the exception of the baboon which had much longer canine teeth to help in its eating of meat.

Thursday, September 8, 2011

Homologous, Analogous

The Tail

Humans vs. Dogs

Humans belong to the kingdom of Animalia according to taxonomy.  Dogs also are a species of the same kingdom.  Humans are bipedal with imposable thumbs as opposed to their best friend the dog, who walk on all fours and have a tail.

Humans also have a tail.  It is a vestigial structure known as the tail bone, or the coccyx.  It is believed that humans possess the tail bone as a result of an ancient ancestor that once possessed a tail, just as a dog has today.  Dogs today use their tails, or caudal vertebrae, today as a means of balance while humans have no beneficiary use of their tail bone.

Scientists believe that all mammals at one point used to be sea animals and eventually grew limbs to be able to walk on land.

Skeleton of a dog

The human eye vs the eye of an octopus

Humans are bipedal mammals that live on land.  The octopus is an eight legged sea creature that lives in deep ocean depths

Although humans and octopus are very different species, they share a common trait amongst each other.  Both the human and the octopus have eyes that they use for their sense of sight. Eyes serve as a the primary structure of interpreting what an organism can see.

I believe that both of the organisms did share an ancient organism with the shared trait.  It's hard to imagine an organism that didn't have the trait of being able to see.  The probability of an organism who can see versus another organism that can't see is astronomical except for some very extreme cases.

Thursday, September 1, 2011

Thursday, August 25, 2011

Darwin's Most Influential

This blog is in response to my Anthropology assignment asking who Darwin's most influential scientist. 

1.) I believe that Charles Lyell, the British lawyer/geologist, had the biggest impact on Darwin as they both held a belief in uniformitarianism.

2.) Charles Lyell is known for his work in the field of geology.  He wrote many books on geology that popularized the idea of the Earth changing due to slow moving processes and forces.  This theory was also known as uniformitarianism.

3.) The point most effected by Lyell in respect to Charles Darwin's work is the point: If the environment changes, the traits that are helpful or adaptive to that environment will be different. Charles Lyell made popular the belief that Earth was gradually changing due to slow-moving processes that supported Darwin's theory of natural selection.  The slow changing of the environment allowed for the idea that some species used to be more successful and after the environment underwent changes, these same species were not as "fit" to continue their species.  Darwin originally lacked a time frame for his theory of evolution until he accepted Lyell's ideas on a slowly changing environment. 

4.) I believe that Darwin may have been able to come up with his theory but it would lack the time frame of how long it took for a species to evolve.  With Lyell's work on explaining the Earth being shaped by gradual processes, Darwin was able to fit in his ideas of gradual change among a population.

5.) The church didn't affect Darwin or his eventual publication very much.  Although many clergymen were quick to dismiss the theory, many other clergyman were able to accept it as part of God's design for natural selection.  The Vatican never officially banned the book or made a statement in regards to his book until recently, some 150+ years later.