Human Variation & Race Blog

1. Select only ONE of the following environmental stresses:  high levels of solar radiation Discuss specifically how this environmental stress negatively impacts the survival of humans by disturbing homeostasis.

Too much ultraviolet light can cause irreversible damage to DNA and important photosynthetic structures, while too much infrared light can cause overheating. DNA damage is caused by UV-B radiation. While most living cells have adapted and can repair simple damage, increased exposure to UV radiation can cause cells to mutate beyond repair, or to die. Overexposure to UVB radiation, which is directly absorbed by the DNA within cells, can potentially cause genetic damage leading to skin cancer, it is the more harmful of the two types of UV radiation.  This damage at the genetic level disturbs homeostasis and is life threatening to the species.

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 adaptation

Skin exposed to UV radiation can develop freckles and rashes. Short-term excessive exposure to UV radiation causes sunburn – reddening, pain and in severe cases blistering and even second degree burns.

Facultative adaptation

A facultative adaptation to protect us from the harmful UVB radiation waves is skin tanning.  Tanning happens when exposure to sunlight triggers a protective mechanism through increased melanin production in the epidermis layer.  Melanin is a natural sunscreen produced by our bodies and the tanning response will remain until the overexposure to UV rays is reduced.  As we spend more time in the sun during the summer months with the warmer weather, it is common to see people of both fair and dark skin have a darker complexion and then to have their complexion return to normal during winter months.  

Developmental adaptation

Nature has selected for people with darker skin in tropical latitudes, especially in nonforested regions, where ultraviolet radiation from the sun is usually the most intense.  Melanin acts as a protective biological shield against ultraviolet radiation.  By doing this, it helps to prevent sunburn damage that could result in DNA changes and, subsequently,several kinds of malignant skin cancers.

Cultural adaptation

As a result humans have used sun screen to avoid the amount of radiation that effect their skin. In order to protect skin from the sun people wear hats and try to avoid the amount of exposure. This in turn has caused a large amount of the population to be vitamin D deficient. 

3. In my opinion there is many benefits of studying human variation across environmental clines. By studying variation across environmental clines we learn how to adapt to the ever changing enviroment and the negative and positive affects that they have on us. They help find a solutions to some diseases and help us understand who gets affected and why.

4.  I would use race initially to understand the variation of the adaptations to try to see who would be more at risk of getting affected by high levels of solar radiation. The study of environmental influences on adaptation is a better way to understand human variation than the use of race. People of a certain race have many different traits within the same race. Race should not be the only thing considered.

Language Blog

Language Blog

Spending at least 15 minutes taking part in a conversation where you are not permitted to speak was very frustrating for my partner and I. Trying to communicate and convey a message to one another was difficult and time consuming. Where a simple question like how was your day took normally about 4 seconds to ask it took about the whole 15 minutes to process and convey that message to each other. My partner did alter the way they communicated because they had no choice. When someone can’t speak to one another the way they receive and process each message can be a little challenging. My partner had to take it very slowly with each sound.

I tried to ask my partner how was your day, but there was no change in topics since we ran out of time trying to communicate. If the balance of power were between two individuals the person starting the conversation would have the power. I feel that the person leading the conversation holds the power because they hold the key in portraying or conveying a message.

If the conversation represented two different cultures, one that uses spoken language and one that did not, the culture that did not speak would have the advantage.  I feel that the culture that already had established a language would be lost trying to figure out what the other culture is trying to convey and would treat them like if they were ignorant. People today are very judgmental towards other cultures. Trying to understand each other’s native language is hard but a culture that does not use symbolic language is even harder.

Communicating for 15 minutes without any physical embellishments was not very difficult. We were able to say what we wanted to communicate but without being able to express feelings through our movements in our hands and face gestures. We would constantly forget that we were not able to communicate without using physical embellishments. It was not difficult to understand but it was a very limited conversation without being able to portray feelings. It was very dry. I feel that this experiment says that the gestures and face expression are a very important part of communicating effectively. The humans portray when someone is sad, angry, passionate, energetic and so many other emotions though a person’s body language tying everything up with the spoken language making the whole conversation more effective.  The benefit to possessing the ability to read body language is that you are able to recognize how someone feels. For example when a person is in love and wants a relationship they are able to express their emotions through body language and that’s how a person finds their mate.

Are there people who have difficulty reading body language and can you identify them? Can you describe a situation where there might be a benefit to not reading someone’s body language, i.e., a situation where perhaps body language does not give you reliable information? There is people that have a difficult time reading body language and usually they are not very effective communicators. They miss a lot of the messages that come from body language. One benefit that body language brings is that you can sense weather or not someone likes you or dislikes you. A disadvantage is that many people misread body language and portrays message completely different from the actual message.

Piltdown Hoax Blog Post

The Piltdown Man was a paleoanthropological hoax in which bones found were presented as fossilized remains of early humans by Charles Dawson at Piltdown, East Sussex England in 1912. The scientific establishment believed that the large modern brain preceded the modern omnivorous diet, and the forgery provided exactly that evidence. In 1949 a fluorine test was performed on bones and it was discovered that skull was about 100,000 year old and of a modern human instead of the skull being million years old and of unknown early human. Jawbone of an orangutan deliberately combined with the cranium of a fully developed modern human. The hoax was exposed in 1953 as a forgery and the suspects have included Dawson, Pierre Teilhard de Chardin, Arthur Keith, Martin A. C. Hinton, Horace de Vere Cole and Arthur Conan Doyle. The Piltdown man fraud significantly affected early research on human evolution.

Scientist’s greed and ambitious need for scientific prestige and to belong to royal society took over not realizing they would affect the scientific work of others. The ethical and honesty of the whole evolution theory was put into question.

The only positive aspect of the scientific process is that the hoax was exposed by using science (fluorine test) and was able to be proven.

It is not possible to remove human factor from science to reduce the chance of errors and avoid another hoax. This would only be possible if the whole process would be run by a computer in the future and the process to be less manual “run by a human” to avoid the possibility of it happening again.

The life lesson is that even though the information comes from a reliable and seemly trustworthy source there is always a need to have proof or evidence that claim is valid.

Analogy/Homology Blog Post

Analogy/Homology Blog Post

Humans and monkeys have similar homologous traits. A monkey's tail and the human tail bone, or coccyx, are examples of homologous structures. Humans and monkeys developed from a common ancestor that had a tail, but while monkeys kept the structure as they evolved, humans did not. The Chimpanzee is a common ancestor to both the human and the monkey.  Chimpanzees do not have tails. They are not like other primates such as the Monkey species; they are more like the Ape, and the Gorilla, which doesn't have a tail.

                                                                        

 Dolphins are mammals and sharks are related more heavily to fish, but the two share several structures with shared functions between the two species. Dolphin and shark dorsal fins and body shape are some analogous traits that are shared between both species. Even though they look very similar I was not able to find any common ancestors and believed it happened thru convergent evolution.

Jean- Baptiste Lamark had the most influence on Darwin’s development of his theory of Natural Selection.

Jean-Baptiste Lanmark suggested

·         dynamic relationship between species and the environment such that the external environment changed.

·         animals activities patterns would change to accommodate new circumstances; physical change would respond to bodily needs and structure would be modified. Alterations would make the animal better suited to its habitat.

·         New traits would be passed on to its offspring. (Proven wrong later).

·         http://evolution.about.com/od/Pre-Darwin/ss/8-People-Who-Influenced-Charles-Darwin.htm#step2states. Article states Lamarck was one of the first to propose humans evolved from a lower species through adaptation over time.  I feel that without Jean-Batiste Lamark, Darwin would not be able to develop his theory of natural selection. I feel that Darwin embraced most of his ideas and developed his own theories after analyzing Lamark. I strongly feel that Darwin’s development of natural selection strongly resembles Lamark. Even though some of Lamark’s ideas were proven incorrect later on, his initial suggestions were taken.