Tuesday, May 31, 2011

High levels of solar radiation



Unquestionably the environmental stress of high levels of solar radiation negatively effects survival humans.Exposure to sunlight can be very harmful to the skin and many people forget or ignore that the sun is one of the most powerful sources of energy in nature. solar radiation have a negative effect on health because one can develop various types of skin cancer. The dark skin help to protect from high solar radiation because dark skin contains a lot melanin so that little solar radiation can penetrate the skin. In other hand, people who have a lighter skin color can easily get sun burns and skin cancer. However, it doe not matter if one has dark or light skin, everyone can be affect by high levels of solar radiation.

2 Identify 4 ways in which humans have adapted to this stress.

a) Short-term adaptation: sunscreen helps to respond quickly to changes of high levels of solar radiation because little solar radiation can penetrate the skin. Sunscreen protects people for a short time, and it is easy to wash off. (I could not find a good answer for this one because sunscreen is a tool of protection)

b) Facultative adaptation: When there is less solar radiation like in winter, skin ability to tan are higher due to the increase in of the melanin granules. this change is much longer than Short-term adaptation

c) Developmental adaptation: humans can adapt over the time to high levels of solar radiation. We can develop more melanin. What is melanin?? Melanin is a dark pigment and filter of defense to solar radiation. It radiation is reflected out and prevented from entering the body. Therefore, melanin is mainly to protect the same skin from sunlight.

d) Cultural adaptation: humans have adapted very well to high levels of sol radiations because we have been developed many tool to protect us from the sun. for example, we created clothing, houses, sunscreen, umbrellas, etc.


3- study human variation in different environmental climes is very beneficial for many reasons. We can understand the causes of many diseases; consequently we know how to prevent them. Studying the high levels of solar radiation we can find the answer of why skin pigmentation is different in places in the world.


4- By studying levels of sol radiation, one can understand the diversity of skin tone among humans. The first actual humans arose in Africa between 120,000 and 100,000 years. They had a dark skin to protect from the solar radiation and high temperatures of the Ecuador. Dark skin contains a lot melanin so that little solar radiation can penetrate the skin. The exposure to sunlight incites the production of vitamin D (It increases absorption of calcium and phosphorus). When humans began to migrate out of the tropics and become established in places where they receive a much lower solar radiation their excessive natural protection against the sun was harmful. The travelers who migrated out from Africa to regions more to the south and north had a big problem developing vitamin D, so it could causes diseases like rickets and another problems related with the calcium. In others words they could not absorbed very well the light of the sun, and produce the enough vitamin D because theirs skin contained too much eumelanin. The only solution was to lose some skin pigmentation. When they began to adapt to in their new environment the melanin changed, and consequently they got a skin color lighter to survive.

Tuesday, May 24, 2011

Language Blog

 
Part 1

To start, I need to say that this assignment was difficult, but at same time funny because I really could not get the message that my friend sent me, and funny because they were just making jokes. Sometimes my friends got a little frustrated because we tried to have a normal conversation about how was our day, and I think that we understand each other like 35%  one of my friend tried to say that he have to picked up his bother in 30 minutes, and I thought that he wanted go to take louche at 3. I could not understand my other friend, but It was great because then she told that was telling me about some shoes that she saw in the mall( I don’t want to offense nobody, but all the shoes look the same for me). Also, when they got tired they wanted to say some world or write the latter in the air; consequently I think that they have frustrated impression about the assignment.

For the third question I do not need to imagine that because when I was 10 years old  I did not know anything of English, and I used to come here in summer to visit my mom and brother. My bother knew a little Spanish, but his friend only spoke English. I really never could understand his friends in conversation.  I think that one one had the advantage to communicating complex ideas. Although Spanish and English different structure, every language is equal to express anything. If we put a speaking culture with a symbolic couture, they would be unable understand each other. For the people that have problems to spoke I think that they develop their own way to being understand quick, I personality will not know what to do to have a conversation to them.



Part 2

It was a new experience for my and my friend because we never  realize how important is for us use hands, head and elevating my voice. And the conversation that we had was kind boring. My friends were affected because my words did not have emotion, and boring. If I wanted to talk about a problem or something that make me sad, they will not get the message. Today understand that body language is important to understand the feelings and emotion of other people.

I think that everyone can understand body language because last semester I took a class of ESL(English as Second Leagues) and I met many international student from around the world like Japan, French, china, North Korea etc. and something we did not  understand some words about what were saying, but the body languages help us to understand if we were boring, sad or happy. In my work  is not an environment to read body language because  my managers seem to be very friendly and nice, but I do not want to start a friendship because I learn that is not professional mix emotion with co-worker or supervisors. When one have a problem at work, it would a bad experience. 

Tuesday, May 10, 2011

Piltdown Hoax Blog Post

 Piltdown fragments were discovered in 1912 by a worker in a quarry and gave to the amateur archaeologist Charles Dawson, who presented them to the eminent paleontologist Smith Woodward (British Museum) in the Geological Society of London. For years the debate has raged about the origin of these remains, and the press said that most likely correspond to “missing link” between apes and humans.The hoax was discovered by a dentist A.T. Marston who examined the teeth and tooth  and a fluorine absorption test. when the true was found out, it was a very polemic because the British were ridiculed, scientific related fields of human evolution began to be more skeptical and people(the mass) started to do not trust in scientific.

To begin, one fault that comes in this case could be that scientific got very excited. The early twentieth century was the golden age of paleontology, and the British were very frustrated because they had not found any human fossil while the rest of Europe and Africa have found a lot. To conclude it is very big mistake make an scientific investigation combining feels, so a scientific must be the most objective possible.

The happiness of British ends when the dentist A.T. Marston found that the teeth of the skeleton belonged to an orangutan course, the loose tooth to a monkey and a human skull. To confirm that, scientific  made the
fluorine absorption test. The principle of this technique is simple: the bones absorb fluoride depending on how long they have been buried. The greater the amount of fluorine present a older bone. The remains of Piltdown’s fragments(both the jaw and skull) contained trace amounts of fluoride. Therefore,  the fragments had been buried in recent times with the intention.


It is impossible to reduce 100% the human factor from the science because science is alive for humans who dedicate their whole life to understand the mysteries of the universe. Scientists still doing mistake in their investigation, but it should not be a signal to stop science.  The Piltdown Man was a dishonesty joke, but in the end authentic scientist found out the true. The only solution to do not have another hoax is remind that scientist must be skeptical about every issues.
  
The story of Piltdown Man as a warning to all of us. We have to investigate further for any issues, so one should make his/her own judgments by and look for every kind of evidence, and be the less impulsive possible in some situations.

Wednesday, May 4, 2011

Comparative Primate



Lemurs: lemurs are endemic to Madagascar and can only be found on this island. Most of the species are arboreal and spend most of their time in trees and bushes. Most parts of the moist and tropical rainforests in the island are home to these animals. There are even desert areas on this island which are also known to serve as lemurs habitat. While most lemurs species enjoy their time high up in trees and bushes, the ring-tailed lemurs prefer being terrestrial

The locomotor behavior of the lemurs is very diverse and their diversity
Lemur Species
Locomotion Behavioral Characteristic
Indris
Vertical clinging and leaping
Bamboo lemurs
Vertical clinging and leaping
Mesopropithecus
Slow arboreal quadrupedal
True lemurs
Fast arboreal quadrupedal
Ruffed lemurs
Fast arboreal quadrupedal
Ring-tailed Lemur
Partially terrestrial quadrupedal
Monkey lemurs
Highly terrestrial quadrupedal
Sloth lemurs
Sloth-like suspensory locomotion



Spider monkeys: they can be found in the forests of Mexico, Central America, and South America. The spider monkeys prefer to be in areas of the rainforests and the semi deciduous forests as well. It has been observed that the spider monkeys rarely come down to the ground level. They prefer to be in the upper portions of the trees.

They use several different types of locomotion: quadrupedal, using all four limbs for locomotion as seen while walking or running; suspensory locomotion used when hanging, climbing or moving through the trees and bipedalism, using only two limbs when leaping. Quadrupedal locomotion is usually observed if the monkey is on a stable relatively substrate free of obstacles.



Baboon: The baboon lives in Ethiopia, Saudi Arabia, Somalia and Yemen. They can be found living from the sea level to 2600 metres. Baboons are extremely adaptable, the major requirement that baboons need for any habitat are water, and safe sleeping places.  Baboons like to sleep either in tall trees or on cliff faces. Baboons locomotor pattern is quadrupedal and on their digits. Walking on their digits means walking on their toes with the heels not touching the ground.  This is known as being a digitigrade quadrupedalism


Gibbons: They live in the deciduous and evergreen rainforests of Southeast Asia. They are arboreal and are very rarely observed on the ground. Spending less than 1% of their time on the ground.
Gibbon’s Locomotor patterns is brachiating when they brachiate, they use four fingers of their hands like a hook (but not the thumb). They can also walk along small branches high up in the air, like tightrope walkers; they use outstretched arms to help keep their balance. Gibbons can also leap acrobatically across large gaps in the tree canopy from tree branch to tree branch

Chimpanzees: live in a wide variety of habitats, including tropical rain forests (in the forest edges and clearings), woodlands, swamp forests, and grasslands in western Africa. While they spend equal time on land and in trees, they do most of their feeding and sleeping in trees.

Locomotion and posture of chimpanzees are quadrupedal and bipedal. the common chimpanzee moves on the ground it moves quadrupedally and bipedally. In addition, in the tree this species also moves in a quadrupedal manner


The ways in how the primates move are very relative to their environment. The above primates show different types of displacement that can be classified in: leaping, arboreal quadrupeds, terrestrial quadrupeds and bipedism. The environment was creating different needs for the primates, so they developed these abilities to survive. In addition, one interesting thing about living in the trees is that it helps primates to be safer from many predators.

Leaping is present in arboreal species to move between discontinuous supports

The arboreal quadrupeds is more appropriate to move from a continuous branches, and is safer for large primates.

Terrestial quadrupeds help move easily land on solid ground.

Bipedism is a form arboreal locomotion in which the primates can swinging from tree branches, only using their arms.

To conclude, it is important to say that the locomotion of the primates is the response of their adaptation to survive in their  environment.