Analysis: How Pigmentation Has Changed Throughout The Years

11. My hypothesis was fairly accurate. Those born with very light pigmentation in a high UV climate wouldn’t have survived, at the same time it makes sense that as the genetics changed more offspring of the successful colour would have been produced.

Two times of melanin are produced within the body, one is called eumelanin and it is responsible for the golden brown color we normally associate with tanning. Another pigment is called pheomelanin and it produces a red color. Redheads and blondes produce more pheomelanin and less eumelanin, which is why they don't tan as well. Sunlight and ultraviolet rays affect the pituitary gland, a gland at the base of the brain that secretes hormones, which then produces melanocyte-stimulating hormone. This hormone flows through the bloodstream to the melanocytes, which makes them able to produce more melanin. (The Science of Tanning)

In the article Skin Deep written by Nina Jablonski and George Chaplin, they discuss and look deeper into the diverse differences in skin color. Our skin color has developed over the years to be dark enough to prevent the damaging sunlight that has been harming our skin and the nutrient folate that it carries. At the same time out skin is light enough to receive vitamin D.

5. In the film, Dr. Jablonski explains that melanin, located in the top layer of human skin, absorbs UV radiation, protecting cells from the damaging effects of UV. Genetics determines the type of melanin (i.e., brown/black eumelanin or red/brown pheomelanin) and the amount of melanin present in an individual’s cells. Based on this information, write a hypothesis for where in the world you would expect to find human populations with

An example of an area would be in the European areas, where the UV radiation doesn’t beam down as strong onto our skin. If it was another hot open area such as Australia then the skin pigmentation stayed darker. In short, the skin pigmentation adapted to the lifestyle and the surround environment to better help survive in that climate. This is due to the body producing more melanin so the effects of the sun’s rays can be counteracted. Through generations successful genes are passed through the blood line, the human body also has a tendency to produce a particular amount of melanin depending on the location of where one

The hormonal changes cause the skin pigments to change too. Other reasons may include the excessive use of cosmetics. Cosmetic products should be used with care and due diligence. One should analyze it carefully the type of cosmetic product that suits the skin. Otherwise it can cause serious repercussions. Moreover the diet you’re taking in also defines your skin type.

The article from www.Sciencedaily.com. “ Natural selection has altered the appearance of Europeans over the past 5,000 years” discusses how scientists have finally discovered how natural selection played a role on the human genome in the past 5,000 years and how it caused transformations in the appearances of people, in their skin, eye and hair pigmentation. This research had been on going for a long time and unfortunately; the methods the geneticists originally used did not produce good results.

This is not too provocative but relevant to this weeks discussion. My husband and I were talking about the lighter skin colors in Neanderthals because of the genome sequencing the scientists have done on DNA from finds. He asked why they would have lighter color skin when they were not even human. I told him

Rana et al. (1999) are interested in human pigmentation variation. What locus did they sample and why? What populations did they sample? Did they include any outgroups? (4 points)

Geographical isolation in the past has caused a variation in skin color; natural selection selected specific skin pigments depending on environmental factors. Early humans who moved to Europe were introduced to a place that had less sunlight than their former place of residence. Overtime, light skin (skin with lower levels of melanin) was selected for since there were not as many UV rays that the skin needed protection from. But, what was wrong with having dark skin in Europe? How is extra melanin a disadvantage in this case? One thing to remember is that even though the sun can provide UV rays, sunlight is also a great source of natural vitamin D (Jablonski; Kirchweger). Vitamin D helps bones absorb calcium and is particularly essential for developing embryos in pregnant women. The adaptation for lighter skin was important because the skin needed to absorb as much sunlight as it could in order to receive optimal amounts of vitamin D (Kirchweger). However, too much vitamin D can be fatal. So as high amounts of melanin protected the skin from excessive UV rays in Africa, they also protected it from excessive vitamin D (Kirchweger).

As the research continues it becomes ever more important to discuss how exactly the differing pigmentation of one race of people actually occurs, because I feel that it has an effect on the way colorism is handled throughout the African American community. There are two ways in which a person of African descent can be of a lighter complexion; the first being amalgamation, which is the coming together of both the black and white races and reproducing to make a mulatto or mixed race child and the second is the use of cosmetic creams in attempt to bleach one’s skin until they too appear mulatto (Dorman 48). This is relevant because, it shows the extremes that people are willing to go to reach the highest plateau of social acceptance. Many of these creams were painful acidic chemicals slowly burning away the pigmentation as people slept, while others were considered mild abrasive materials used to “gently” scrape away dark pigments (Dorman

Many things that were thought to be dangerous in the past are now things that are seen or used everyday. One of these things was tomatoes. Tomatoes were once thought to be very deadly. People avoided them at all cost because they thought these fruits could kill you. These people believed that tomatoes were poisonous for many years. After eliminating tomatoes from their diets, it was observed that people were still being killed by what people thought they were not ingesting. After this conclusion, people decided to investigate these common plants further. It was discovered that the tomato itself was not poisonous, but the cutlery that was used by the people was. Instead of being poisoned by a fruit, they were being

Within European populations eye colors such as blue, gray, hazel, and green are found at much greater rates than in any other part of the world. The frequency of the trait for light colored eye varies quite a bit with some regions of Europe experiencing levels as low as 50%, and some experiencing levels as high as 80% or greater. Globally however, brown, or black eye color is the more prevalent iris color. This high frequency of dark eye color globally has led many geneticist’s to believe that at one time all humans had the phenotypic trait of brown eye color. They argue that the much higher melanin concentration found in the brown colored iris would have offered our ancestors greater protection from eye diseases such as macular degeneration which can be brought on by an over exposure to UV radiation from the sun, and such protection may well have acted as a selective force favoring brown eye color (Duffy et al., 2007; Sturm and Larsson,

The evolution of human being has been linked to human variation where the variation will be in reference to the biological aspect of the human being which will relate to the racial differences that may include the physical differences, as well as the skin, and the skeleton of the human being. However, despite the variations which may be seen in terms of race, in the current world today, human beings belong to the same particular species which is normally known as Homo sapiens.

Color fills our world with beauty. We delight in the colors of a magnificent sunset and in the bright red and golden-yellow leaves of autumn. We are charmed by gorgeous flowering plants and the brilliantly colored arch of a rainbow. We also use color in various ways to add pleasure and interest to our lives. For example, many people choose the colors of their clothes carefully and decorate their homes with colors that create beautiful, restful, or exciting effects. By their selection and arrangement of colors, artists try to make their paintings more realistic or expressive.