Essay about The Evolution of Skin Colour

Many people think that is it possible to achieve a “healthy tan,” but this thought has been proven wrong. Overexpose to UV-A and UV-B rays from the sun lead to premature aging of the skin, as well as the possible formation of skin cancer, know as melanoma. An appearance of a tan is actually a stage of burning and damage to the skin. Although a tan may be desirable to many, the fact remains that more people need to be educated on the dangers of the sun’s harmful rays, and the possible health complications of overexposure.

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).

Anthropologists and geographers have studied and overtime come to the conclusion that distribution of skin color is not random. Darker skin color has been found to typically come from near the equator and lighter skin colors are typically coming from closer to the north and south poles. Over the years, researchers have found that darker skin colors has protected the

Caucasians have the lowest amount of melanin in their skin cells when being compared to other cultures. Melanin is crucial to protecting our skin from UV rays, and so someone with a darker skin tone is better protected.

It develops in the melanocytes, which are cells that produce melanin that gives the skin its pigment or color and protects tissues from ultra violet radiation. Dark skinned people have more melanin than light skinned people do. For this reason, Melanomia is more frequent in light skinned people. (“Detailed description “, 2000, P.2

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

The basic component in tanning is ultraviolet light. Ultraviolet light, whether produced by a tanning unit or by the sun, contains two components; UVA and UVB. These are the two types of ultraviolet radiation that are known to negatively effect the skin. UVA has a longer wavelength that causes photoaging and can produce some melanomas. UVB has a shorter wavelength that also causes photoaging and has been implicated in skin cancers. Photoaging is the premature aging or deep wrinkling of skin. Indoor tanning units utilize both forms of light waves to tan a person with a minimized risk of sunburn. Tanning outdoors does not give you this option because the sun omits every type of UV rays, so a person is more likely to burn. A person’s skin epidermis consists of two layers: The germinative layer and the horny layer. Another name for the germinative layer is the “living layer.” And another name for the horny layer is the “dead” layer. When exposed to ultraviolet light, melanocytes in the germinative layer produce melanin that is absorbed by surrounding cells. Melanin is a dark pigment found in the pigment-bearing cells of the skin, and melanocytes are epidermal cells capable of synthesizing melanin. This creates a protective barrier from ultraviolet light reaching deeper into the layers of the skin. The pale pink melanin granules are stored in the core of keratin cells. UVA darkens the melanin,

As many as ninety percent of melanomas are estimated to be caused ultra violet (UV) exposure. This includes UV exposure from artificial sources, such as tanning beds. “Strong evidence now links tanning beds to melanoma, a deadly form of skin cancer that afflicts nearly 69,000 Americans a year.”—USA Today. The more one tans and the younger one is your risk for melanoma increases. However, melanoma is increasing faster in women 15-29 years old, than in men the same age. Furthermore, 10,000 people die from melanoma. This is mainly caused because of tanning beds. As a matter of fact, a person dies every fifty minutes from melanoma, the second most common cancer. Tanning beds triple the risk of one getting melanoma. In fact, every time one goes and tans, the risk gets higher and higher. Following this further, more people get melanoma because of tanning beds than developing lung cancer because of

Have you ever felt the “false sense of security that [you] may not feel under direct sunlight” from a tanning bed (Jeffrey)? Your body relaxes, you feel serene, and you get a golden glow. Some teens strive for this feeling...and the tan. Tanning is the skin's response to injury, according to Arielle Kauvar, M. D. The exposure of UV rays over time can cause skin cancer. Skin cancer is the growth of abnormal growth of skin cells that forms in the tissue of the skin (Skin Cancer). Melanoma, the most dangerous type of skin cancer, can come from UV rays. From 1998- 2008, the number of cases of Melanoma has increased by about

Melanoma is the most dangerous type of skin cancer. It develops when unrepaired DNA damage to your skin cells trigger genetic defects that lead you skin cells to multiply at a fast pace and form tumors. Melanoma can often resemble moles and some can come from previous moles. These melanoma moles can range in color from pink, red, brown, purple, white, blue and skin-colored, but more mostly seen as black or brown. It’s said that consumers who use indoor ultraviolent tanning devices are seven-four percent more likely to develop melanoma compared to someone who has never used a tanning bed before. Melanoma is usually caused from intense and over exposure to UV radiation. It has be estimated to kill around 10,000 individuals in the U.S. each year. The lifetime risk of melanoma is 1.5 times higher in males than in females. Melanoma is curable, if it is recognized early and

Applying a sunscreen with a skin protection factor of 15-30, wearing protective clothing such as thin jackets, hats, and sunglasses, and limiting time in the sun when possible are all effective options for protecting your skin against the effects of UV rays. I personally have an olive complexion and have never experienced the effects of sunburn and have often reveled in the tanning effect of time spent in the sun. It is now clear to me that no matter your skin tone, it is crucial to protect yourself from the deeper effects of exposure to UV rays and it is not as simple as using sunscreen to avoid a burn. Additionally, informing others of the significant risk associated with tanning beds is everyone’s responsibility. The risk of melanoma increases by 75% to those who use tanning beds before the age of 35; it is painfully clear that dangers of allowing the benefits of a temporarily dark complexion to outweigh the risks is both irresponsible and

2. Melanoma is also more common in people who live in areas with large amounts of UV

A major function of melanin is to act as a defensive barrier of the skin against radiation damage. Ultraviolet light between the wavelengths 280-320nm (UV-B) causes sunburn and damages the skin on nonpigmented peoples. Exposure to this degree of light causes their skin to become dry, leathery, and wrinkled in appearance similar to that associated with aging. This can be seen in Whites living in Australia and South Africa, where ultraviolet light intensity is high because of the relative latitude or closeness to the equator.

We often connect ourselves to the world through our appearances. One of the first characteristics we notice about another human is the color of their skin. It is unavoidable, as the largest organ of the body, it covers and highlights our individual features and forms a protective wall against the elements. There is no escape from the social repercussions our pigmentation causes no matter what range of the very broad spectrum of color we fall into. I have never thought so much about the genetic and social evolution of skin and its properties until I read Nina Jablonski’s Living Color: The Biological and Social Meaning of Skin Color. This book encompasses, in great detail, how our skin has evolved, adapted and mutated throughout time and in what

Traditionally, tanned skin was undesirable to the public. Prior to the industrial revolution, most manual labor was done outside under the sun where such constant exposure resulted in darker skin. Consequently, because manual labor was a staple of the lower classes, tanned skinned also became associated with the destitute