Melanin
Melanin has played a significant role in human evolution. In this paper I will discuss the importance of melanin in its role in the human biological system and how it relates to the natural selection of suitable human life according to geography and environment.
Human pigmentation is influenced by hemoglobins within blood vessels in the skin, carotene and melanins. Melanin, the basis of pigmentation, can be found in the forms of eumelanin and phaeomelanin. Eumelanin is the brown-black pigment located in the skin, hair, and eyes. Phaeomelanin is a yellow to reddish-brown pigment found in small quantities within the skin, eyes, and red hair. Because of these two pigments, to a greater or lesser degree, we have the variation in human pigmentation that is seen today.
Melanin is the product of cells located within the skin called melanocytes.The function of melanocytes is to manufacture the pigments eumelanin and phaeomelanin. Eumelanin, which is more photostable than phaeomelanin, is the main product of the melanocytes. In melanin, various chemicals, under the influence of enzymes, build a very stable compound that is distributed throughout the body of pigmented peoples. In an experiment by Wasterstrom, 1984, melanin exposed to up to 600 degrees C was shown to retain close to 50% of its original properties. In addition, melanin has been found in 1,000-year-old mummies and in extinct mammoth skins, according to Daniels et al., 1972.
After production, melanin is packaged in membrane bodies called melanosomes. Dark skin has large melanosomes that are in a single state and also contains more melanosomes than lighter skin such as in Europeans. Most Asian skin, on the other hand, has smaller concentrated groups of melanosomes, whereas European skin has the smallest melanosomes, which are combined into bound materials. The spacing and amount of melanosomes are what gives the appearance of skin color due to the dispersal of light hitting the skin.
A study of Melanesians found that the darker skinned inhabitants possessed large, singly dispersed melanosomes, whereas the lighter skinned inhabitants had smaller melanosomes bound in complexes . This infers that the large single state melanosome is directly related to dark skin. The size of these melanosomes are not specific to "race". For example, Africans with light skin contain the smaller ...
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...pplements and sun block creams have allowed individuals to stay healthy in many parts of the world, causing the adaptive qualities of skin and hair pigmentation to be minimized.
In conclusion, melanin production has played a considerably important role in human evolution. Not only does it influence color pigmentation through its protective role of defending against harmful UV rays, but also determines detrimental features such as eye-sight and hearing. Furthermore, melanin production and its evolutionary adaptions mark an important presence upon our biological systems to this day. Therefore, in the process of furthering human evolution, melanin production has played an enormous role in human evolution by selecting for several features that allow for particular adaptions according to the human's geographical location and environment.
Bibliography
Kitties, Rick. "Nature, Origin, and Variation of Human Pigmentation." Journal of Black Studies, Sep '95, Vol. 26 Issue 1, p36, 26p,
Hamilton, William J. Life's Color Code. McGraw-Hill Book Company. New York, 1973. Chapter 10.
Weiss, Peter. "Blue Eyes, Big Earplugs, Bad Hearing?" Scien
Based from the film “melanin plays a role on how Africans have been able to create and developed some of the sciences that they have come to be known for”. It is also believe that melanin is a factor to soul because people with more of it moves, speaks, and acts differently than those who do not. According to a group of Africans known as the “melanin scholars” they reported a scientific base that “melanin is involved in the regulation of all psychological and physiological processes of the human body.” This makes people with more melanin stronger and smarter than those with less.² This is why, according to Welsing, whites had ambition to destroy the African race because they were inferior to their genetic superiority. In agreement to Welsing, Wade Nobles, Richard King, and other researchers/ scientists reported that whites are not entirely human since they stopped evolving with the central nervous system
Melanocytes, embryologically derived from the neural crest, are distributed in the epidermis and thus are found throughout the skin. They produce a brown pigment known as melanin and are responsible for racial variation in skin color and also the color of moles. Malignant degeneration of the melanocyte gives rise to the tumor, melanoma, of which there are four subtypes. These are: superficial spreading, nodular, lentigo maligna, and acral lentiginous melanomas, accounting for 70%, 15% to 30%, 4% to 10%, and 2% to 8% of cases, respectively. Malignant melanoma may develop anywhere on the body. In men, it is most common on the trunk. In women, it is most common on the back or legs. The subtype also may influence where the tumor develops, lentigo melanoma is more common on the face while acral lentiginous melanoma is more common on the palms of the hand, soles of the feet, or in the nail beds.
During the First Punic War Rome, Rome successfully defeated the Carthage. The conflict was chiefly due to who would control the important trade waterways of the Mediterranean Sea.
In today’s culture, being tan coincides with what is believed to be beautiful. As a result, it is no surprise that in the United States of America, an estimated 922,000 people are currently living with some level of melanoma. Even though the news media and doctors warn people about the risks of too much sun exposure and give information as to how to prevent contracting skin cancer, people are still disregarding this important information and going into the sun for extended periods of time unprotected.
Have you ever wondered how and why people are different colors? This paper discusses the evolutionary theories behind diversity in human skin pigment. Though previous theories hypothesized that darker skin evolved in order to protect people from sunburn and skin cancer, the prominent theory today relates to folate protection and vitamin D production.
The word melanoma comes from the Greek words, melas (black) and -oma (tumour). It is a very serious cancer that most often occurs in the skin and less frequently in the eye or in the lining of the nose, mouth, or genitals. Melanoma begins in melanocytes, cells that make a pigment called melanin. Both light- and dark-skinned people have melanin, which gives colour to the skin, hair, and parts of the eye.
Melanin helps reduce the absorption of wavelengths into the skin (Chaplin, Jablonski, 59). The more melanin in the skin, the greater the protection against harmful UV rays, and the amount of melanin in the skin correlates with the skin’s color (more melanin means darker skin)....
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 skin from having skin cancer. Recent studies have shown that “skin color is the product of natural selection acting to regulate the effects of the sun’s ultraviolet radiation on key nutrients crucial to the reproductive success” (169).
Melanin is the body’s way of protecting the skin this is why darker people tan easier because their melanocytes produce more melanin.
When people are exposed to UV light, from the sun or, for example, in a tanning booth, the melanocyte cells make more melanin and pack together tighter, resulting in darker skin tones. If the skin is receiving too much ultraviolet light, the melanocytes may begin to grow abnormally and become melanoma during this process.
The color of your skin used to depend on where you live. (Before transportation became so easy.) Darker skinned people would live where it is hotter, and the sun shines more. Lighter skinned people would live in cooler, less sunny areas. This is because the darker pigments in your skin would keep you from burning.
For instance, some may want to learn a new language for a job opportunity, but then learning a new language, in itself, paves new roads for your professional opportunities.
Jablonski, N. G. (2000, Feb). The Evolution of Human Skin Coloration. Retrieved October 6, 2011, from http://www.bgsu.edu/departments/chem/faculty/leontis/chem447/PDF_files/Jablonski_skin_color_2000.pdf
Therefore, this is able to encourage the ability to communicate and appreciate the depth and diversity of the world. Communication with two different countries, or three, or four, will further bring the world closer together, in hopes of closing the divide between some countries. By learning a second language, it can significantly broaden your native language as it gives you stronger vocabulary skills, improved literacy skills and a better understanding of the grammar and construction of your own native language. Furthermore, this can help you in other educational studies. Though it is possible to travel to another country without acquiring the native language, the experience you will have is greatly diminished as you will not see beyond the surface of their culture. Additionally, knowing the native language makes travelling easier, by being able to order meals in restaurants, ask and understand directions. Additionally, it makes it easier to find accommodation, it’s more enjoyable, informative and more satisfying. You are able to further understand and appreciate international literature, music and films, by being able to understand word plays, innuendoes, cultural references, metaphors and further improve your ability to speak the
The issue focused on importance of learning of foreign languages. Many people ask "Why should I learn foreign languages?" Learning a foreign language takes assiduity and free time. In order to understand this importance we need first to understand benefits of knowing and learning foreign languages. I offer several groups of these benefits below, which may help to convince you to take the plunge, if you need such persuasion. One groups of benefits represent economic and practical reasons, others have intellectual and even sentimental content, but whatever reasons you choose, you will have a clear idea of why learning foreign language so important and how it can help to motivate you in your studies.