Evolution of human skin colour

Tanning involves not just the increased melanin production in response to UV radiation but the thickening of the top layer of the epidermis, the stratum corneum. The lighter skin color in Europeans has been linked to ThrAla allele as well as to SerTyr, while it is seldom found in any other ethnic group.

The environment was incredibly sunny and provided little shelter. Research indicates the selection for the light-skin alleles of these genes in Europeans is comparatively recent, having occurred later than 20, years ago and perhaps as recently as 12, to 6, years ago.

They no longer needed as much protection from the sun, and the melanin was blocking out essential vitamin D. This would also cause them to have very dark skin.

There are several factors in the story of how our skin evolved to be the color that it is. But really, if all humans started out from the same place on earth, how did our skin become different colors? But it can also cause conditions such as premature skin aging and skin cancer. Melasma describes the darkening of the skin.

But different groups of people in Africa have almost every skin color on the planet, from deepest black in the Dinka of South Sudan to beige in the San of South Africa.

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Research shows at least 10 differences in MC1R between African and chimpanzee samples and that the gene has probably undergone a strong positive selection a selective sweep in early Hominins around 1.

The team proposes that the variants arose in Africa as early as 1 million years ago and spread later to Europeans and Asians. All of them are caused by different genetic mutations.

Modern Human Diversity - Skin Color

In the summer they get high levels of UV rays reflected from the surface of snow and ice, and their dark skin protects them from this reflected light.

At the same time, they collected blood samples for genetic studies. Alternatively, this great migration may have included people carrying variants for both light and dark skin, but the dark variants later were lost in Eurasians.

In some people, the armpits become slightly darker during puberty. Vitamin D helps with our immune system, cell growth, and calcium intake.

Albinism is a recessively inherited trait in humans where both pigmented parents may be carriers of the gene and pass it down to their children. UV rays can, for example, strip away folic acid, a nutrient essential to the development of healthy fetuses. Men and women are not born with different skin color, they begin to diverge during puberty with the influence of sex hormones.

For those with darker skin colors, these discolorations can appear as patches or areas of ashen-gray skin. The cause of vitiligo is unknown, but research suggests that it may arise from autoimmunegenetic, oxidative stressneural, or viral causes.

Following these markers through the generations reveals a genetic tree of many diverse branches, each of which may be followed back to where they all join — a common African root.

Generally, those who start out with darker skin color and more melanin have better abilities to tan. In a person with albinism, melanocytes can be entirely absent, or fail to produce melanin, or melanosomes can fail to mature and be transferred to keranocytes.

The more melanin someone has, the darker their skin will be.

Human skin color

Irregular Pigmentation Irregular pigmentation is characteristic of all individuals regardless of their ethnic background. Around the same age, women experience darkening of some areas of their skin.

UV rays can, for example, strip away folic acid, a nutrient essential to the development of healthy fetuses. Humans with different skin colors are now spread out all over the world. That idea, however, counters three genetic studies that concluded last year that Australians, Melanesians, and Eurasians all descend from a single migration out of Africa.

The study adds to established research undercutting old notions of race.

Human Skin Color Variation

The climate was extremely hot, the landscape a dry, open savanna. The evolution of a naked, darkly pigmented integument occurred early in the evolution of the genus Homo. The most dramatic discovery concerned a gene known as MFSD Skin with high amounts of melanin would have protected early humans from dying of diseases caused by UV rays before they could reproduce and pass on their genes.

But different groups of people in Africa have almost every skin color on the planet, from deepest black in the Dinka of South Sudan to beige in the San of South Africa.

Human skin color

In the summer they get high levels of UV rays reflected from the surface of snow and ice, and their dark skin protects them from this reflected light.Skin coloration in humans is adaptive and labile.

Skin pigmentation levels have changed more than once in human evolution. Because of this, skin coloration is of no value in determining phylogenetic relationships among modern human groups.

Modern Human Diversity - Skin Color

In evolution, skin pigmentation in human beings evolved by a process of natural selection primarily to regulate the amount of ultraviolet radiation penetrating the skin, controlling its biochemical effects.

The actual skin color of different humans is affected by many substances, although the single most important substance is the pigment melanin. Many aspects of the evolution of human skin and skin color can be reconstructed using comparative anatomy, physiology, and genomics.

Enhancement of thermal sweating was a key innovation in human evolution that allowed maintenance of homeostasis (including constant brain temperature) during sustained physical activity in hot environments. Skin coloration in humans is adaptive and labile.

Skin pigmentation levels have changed more than once in human evolution. Because of this, skin coloration is of no value in determining phylogenetic relationships among modern human groups. Variations in human skin color are adaptive traits that correlate closely with geography and the sun’s ultraviolet (UV) radiation.

As early humans moved into hot, open environments in search of food and water, one big challenge was keeping cool. New gene variants reveal the evolution of human skin color.

By Ann Gibbons Oct. 12,PM. Most people associate Africans with dark skin. But different groups of people in Africa have almost every skin color on the planet, from deepest black in the Dinka of South Sudan to beige in the San of South Africa.

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Evolution of human skin colour
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