what caused humans to evolve different skin tones
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Human biological adaptability Skin color is due primarily to the presence of a pigment called melanin , which is controlled by at least 6 genes. Both light and dark complexioned people have melanin. However, two forms are produced--pheomelanin , which is red to yellow in color, and eumelanin , which is dark brown to black. People with light complexioned skin mostly produce pheomelanin, while those with dark colored skin mostly produce eumelanin.
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Human skin color Research indicates the selection for the light-skin alleles of these genes in Europeans is comparatively recent, having occurred later than 20,000 years ago and perhaps as recently as 12,000 to 6,000 years ago.
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Alone we are rare. Together we are strong.â¥ Donate Today This range of colors comes from the amount and type of a pigment called melanin found in the skin. There are two types of melanin--eumelanin and pheomelanin. In general, the more eumelanin in your skin, the darker your skin will be. People who make more pheomelanin than eumelanin tend to have lighter skin with freckles.
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Human skin color People have different skin colors mainly because their melanocytes produce different amount and kinds of melanin. The genetic mechanism behind human skin color is mainly regulated by the enzyme tyrosinase, which creates the color of the skin, eyes, and hair shades. Differences in skin color are also attributed to differences in size and distribution of melanosomes in the skin. Melanocytes produce two types of melanin.
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Human biological adaptability In lighter skin, color is also affected by red cells in blood flowing close to the skin. To a lesser extent, the color is affected by the presence of fat under the skin and carotene, a reddish-orange pigment in the skin. Hair color is also due to the presence of melanin. Melanin is normally located in the epidermis , or outer skin layer.
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Human skin color Human skin pigmentation is the result of natural selection. Skin pigmentation in human beings evolved primarily to regulate the amount of ultraviolet radiation penetrating the skin, controlling its biochemical effects.umelanin is found in hair, areola, and skin, and the hair colors grey, black, yellow, and brown. In humans, it is more abundant in people with dark skin. Pheomelanin, a pink to red hue is found in particularly large quantities in red hair, the lips, nipples, glans of the penis, and vagina.
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Human skin color Melanin is formed through the process of metabolization of tyrosine, which is an amino acid. In the skin, melanin is produced by cells called melanocytes. There are certain conditions in the body that involve melanin. For example, albinism is a condition where the body lacks melanin.In albinism, the normal amounts of pigment in the body are not there.It is not only humans that suffer from albinism.n the skin, melanin is produced by cells called melanocytes. There are certain conditions in the body that involve melanin. For example, albinism is a condition where the body lacks melanin. In albinism, the normal amounts of pigment in the body are not there. It is not only humans that suffer from albinism.
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Skin Pigment Disorders Skin color is determined by a pigment (melanin) made by specialized cells in the skin (melanocytes). The amount and type of melanin determines a person's skin color. Melanin gives color to the skin, hair, and iris of the eyes. Levels of melanin depend on race and amount of sunlight exposure. Sun exposure increases melanin production to protect the skin against harmful UV (ultraviolet) rays. In addition, hormonal changes can affect melanin production.
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Modern Human Diversity - Skin Color As people moved to areas farther from the equator with lower UV levels, natural selection favored lighter skin which allowed UV rays to penetrate and produce essential vitamin D. The darker skin of peoples who lived closer to the equator was important in preventing folate deficiency.
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- Human skin color ranges in variety from the darkest brown to the lightest pinkish-white hues. Human skin pigmentation is the result of natural selection. Skin pigmentation in human beings evolved primarily to regulate the amount of ultraviolet radiation penetrating the skin, controlling its biochemical effects.he genetic mechanism behind human skin color is mainly regulated by the enzyme tyrosinase, which creates the color of the skin, eyes, and hair shades. Differences in skin color are also attributed to differences in size and distribution of melanosomes in the skin.
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- Or eastern and southern Asians. Why different skin colors may have evolved. It is pretty obvious that people whose ancestors come from Northern Europe or Japan tend to have lighter skin than people whose ancestors are from sub-Saharan Africa or Australia.
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Human biological adaptability In addition, individuals differ in the number and size of melanin particles. The latter two variables are more important in determining skin color than the percentages of the different kinds of melanin. In lighter skin, color is also affected by red cells in blood flowing close to the skin.
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Human evolution Human evolution Human evolution is the lengthy process of change by which people originated from apelike ancestors. Scientific evidence shows that the physical and behavioral traits shared by all people originated from apelike ancestors and evolved over a period of approximately six million years. One of the earliest defining human traits, bipedalism -- the ability to walk on two legs -- evolved over 4 million years ago. Other important human characteristics -- such as a large and complex brain, the ability to make and use tools, and the capacity for language -- developed more recently.
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- Unrelated people whose ancestors came from the same part of the world often are generally similar in terms of such body features as skin and hair color, facial characteristics, body shape, and stature. Not surprisingly, these traits have a strong genetic component as well. However, they can be affected by environmental influences. For instance, skin color often can be darkened, or tanned, seasonally by prolonged exposure to ultraviolet radiation from the sun. Likewise, stature can be affected by nutrition.
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- In the case of illness or injury, the person's skin may change color, becoming darker (hyperpigmentation) or lighter (hypopigmentation). Hyperpigmentation in skin is caused by an increase in melanin, the substance in the body that is responsible for color (pigment).
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Human evolution Human evolution is the lengthy process of change by which people originated from apelike ancestors. Scientific evidence shows that the physical and behavioral traits shared by all people originated from apelike ancestors and evolved over a period of approximately six million years. One of the earliest defining human traits, bipedalism -- the ability to walk on two legs -- evolved over 4 million years ago.
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How Did Skin Color Evolve? Updated November 29, 2015. There is no doubt that there are many different shades and skin colors across the world. There are even very different skin colors that live in the same climates. How did these different skin colors evolve? Why are some skin colors more prominent than others? No matter your skin color, it can be traced back to human ancestors that once lived on the continents of Africa and Asia.
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Human evolution Over time, genetic change can alter a species' overall way of life, such as what it eats, how it grows, and where it can live. Human evolution took place as new genetic variations in early ancestor populations favored new abilities to adapt to environmental change and so altered the human way of life. Dr. Rick Potts provides a video short introduction to some of the evidence for human evolution, in the form of fossils and artifacts.
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- Skin color is due primarily to the presence of a pigment called melanin , which is controlled by at least 6 genes. Both light and dark complexioned people have melanin. However, two forms are produced--pheomelanin , which is red to yellow in color, and eumelanin , which is dark brown to black.
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Human skin The actual skin color of different humans is affected by many substances, although the single most important substance is the pigment melanin. Melanin is produced within the skin in cells called melanocytes and it is the main determinant of the skin color of darker-skinned humans. The skin color of people with light skin is determined mainly by the bluish-white connective tissue under the dermis and by the hemoglobin circulating in the veins of the dermis.
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Human skin color Melanin: The pigment that gives human skin, hair, and eyes their color. Dark-skinned people have more melanin in their skin than light-skinned people have. Melanin is produced by cells called melanocytes.It provides some protection again skin damage from the sun, and the melanocytes increase their production of melanin in response to sun exposure.Freckles, which occur in people of all races, are small, concentrated areas of increased melanin production.elanin: The pigment that gives human skin, hair, and eyes their color. Dark-skinned people have more melanin in their skin than light-skinned people have. Melanin is produced by cells called melanocytes.
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Human skin color Human skin color ranges in variety from the darkest brown to the lightest hues. An individual's skin pigmentation is the result of genetics, being the product of both of the individual's biological parents' genetic makeup.
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Human skin color Extended Coloured family from South Africa showing some spectrum of human skin coloration. Human skin color ranges in variety from the darkest brown to the lightest hues. An individual's skin pigmentation is the result of genetics, being the product of both of the individual's biological parents' genetic makeup.
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Hormones in Ethnic Skin Human skin color can vary from almost translucent to almost black. This range of colors comes from the amount and type of a pigment called melanin found in the skin. There are two types of melanin--eumelanin and pheomelanin. In general, the more eumelanin in your skin, the darker your skin will be. People who make more pheomelanin than eumelanin tend to have lighter skin with freckles. Like many other traits, the amount and kind of pigment in your skin is controlled by genes.
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The Evolution of Human Skin Color Folate is linked to natural selection which can be caused by excessive exposure then theirs a higher chance of problems in pregnancy. All other things being equal which skin tone would you expect to be correlated with higher levels of folate.
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Accounting Clerk Job Description Sample Supports accounting operations by filing documents; reconciling statements; running software programs. This accounting clerk sample job description can assist in your creating a job application that will attract job candidates who are qualified for the job.Feel free to revise this job description to meet your specific job duties and job requirements.ccounting Clerk Job Duties: 1  Maintains accounting records by making copies; filing documents. 2  Reconciles bank statements by comparing statements with general ledger. 3  Maintains accounting databases by entering data into the computer; processing backups.