How to replace the word nigger, nigga, nig ext. as a cool terminology or jester for black affectionate greeting towards one another. Replace it the word mellin. what's up mellin, melan, mellan. you feel where I'm coming from. Its time for a change, real change we can believe in.
Melanin reduces ultraviolet induced DNA damage by absorbing or scattering the ultraviolet radiation that otherwise would have been absorbed by the DNA. This prevents the development of melanoma, a potentially deadly form of skin cancer, as well as other health problems related to exposure to strong solar radiation. The amount of UV radiation that is absorbed or scattered is determined by a number of factors: the size, shape, and distribution of melanosomes, as well as the wavelength of the incident ray.
Skin color depends upon the size, number, shape, and distribution of melanosomes, as well as the chemical nature (level of activity) of their melanin content. There are 6 different skin types that are defined by dermatologists.
There is a striking correlation between geographic conditions, particularly exposure to sunlight, and skin tone. These differences have evolved to find the balance between the benefits and the dangers of the ultraviolet (UV) radiation we absorb from the sun.
Early humankind living in the sun-soaked savannah plains of Africa developed a dark-toned skin, rich in the pigment melanin. Within the skin cells, melanin concentrates above the nucleus, shielding the vital DNA from radiation damage. In an environment where there is little to break the path of sunlight onto the skin, this barrier is a great advantage.
There are other benefits to having a high concentration of melanin in the skin and other parts of the body. Melanin boosts the immune system, and darker-skinned groups have been shown to have a lower incidence of a number of serious diseases, including Parkinson’s, multiple sclerosis, and spina bifida. Darker-skinned individuals also age better, as their skin is better protected from sun damage.
It seems that, as early peoples migrated away from the equator into areas less exposed to the sun, there was not enough UV radiation to produce sufficient vitamin D to prevent diseases such as rickets. Their bodies compensated by producing less melanin, so that more sunlight would be allowed through. They could then produce sufficient vitamin D with less exposure to sunlight.
Light-skinned people visiting sunny locations may not have enough melanin to block the sun sufficiently, and may burn their skin without the protection of sunblock. Dark-skinned people visiting areas where there is less exposure to the sun may apparently not produce enough vitamin D, but can get it from supplements or food sources. Many foods such as milk and bread are now vitamin D fortified.
As the distribution map of skin color shows, skin color variation is not deter mined purely by distance from the equator. For example, people in snow-covered areas often have a dark skin tone. This may be because they are exposed to high levels of reflected UV radiation from the snow, or because their diet with its high proportion of fish is rich in vitamin D.
Skin color
Image showing the absorption spectra curve of melanin, and also the irradiance/insolation from the sun, and the absorption curve of DNA. (one graph).Melanin reduces ultraviolet induced DNA damage by absorbing or scattering the ultraviolet radiation that otherwise would have been absorbed by the DNA. This prevents the development of melanoma, a potentially deadly form of skin cancer, as well as other health problems related to exposure to strong solar radiation. The amount of UV radiation that is absorbed or scattered is determined by a number of factors: the size, shape, and distribution of melanosomes, as well as the wavelength of the incident ray.
Skin color depends upon the size, number, shape, and distribution of melanosomes, as well as the chemical nature (level of activity) of their melanin content. There are 6 different skin types that are defined by dermatologists.
Table showing different skin colors
| Skin type | Description |
|---|---|
| Type 1 | Always burns, never tans. Very fair skin with red or blond hair and freckles. |
| Type 2 | Burns easily, tans minimally. Fair skin. |
| Type 3 | Sometimes burns, gradually tans. |
| Type 4 | Minimum burning, always tans. White, with medium pigmentation. |
| Type 5 | Seldom burns, always tans. Medium to heavy pigmentation. |
| Type 6 | Never burns, but tans very darkly. African Americans, Africans, or dark-skinned individuals with heavy pigmentation. |
Balancing the benefits and the dangers of ultraviolet radiation for differing climates
The darkest skin tones are found in tropical latitudes with open grassland, while areas further from the equator that are forested tend to favor lighter skin tones
Early humankind living in the sun-soaked savannah plains of Africa developed a dark-toned skin, rich in the pigment melanin. Within the skin cells, melanin concentrates above the nucleus, shielding the vital DNA from radiation damage. In an environment where there is little to break the path of sunlight onto the skin, this barrier is a great advantage.
There are other benefits to having a high concentration of melanin in the skin and other parts of the body. Melanin boosts the immune system, and darker-skinned groups have been shown to have a lower incidence of a number of serious diseases, including Parkinson’s, multiple sclerosis, and spina bifida. Darker-skinned individuals also age better, as their skin is better protected from sun damage.
Vitamin D and skin color: finding a balance
It is the UV component of sunlight that helps the body utilize vitamin D. This vitamin helps promote bone growth, maintaining the right balance between calcium and phosphorus in the body. A deficiency of vitamin D leads to rickets and similar diseases.It seems that, as early peoples migrated away from the equator into areas less exposed to the sun, there was not enough UV radiation to produce sufficient vitamin D to prevent diseases such as rickets. Their bodies compensated by producing less melanin, so that more sunlight would be allowed through. They could then produce sufficient vitamin D with less exposure to sunlight.
Light-skinned people visiting sunny locations may not have enough melanin to block the sun sufficiently, and may burn their skin without the protection of sunblock. Dark-skinned people visiting areas where there is less exposure to the sun may apparently not produce enough vitamin D, but can get it from supplements or food sources. Many foods such as milk and bread are now vitamin D fortified.
As the distribution map of skin color shows, skin color variation is not deter mined purely by distance from the equator. For example, people in snow-covered areas often have a dark skin tone. This may be because they are exposed to high levels of reflected UV radiation from the snow, or because their diet with its high proportion of fish is rich in vitamin D.
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Grains in breads and cereals are often fortified with vitamin D.
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Fish is a natural source of vitamin D.
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