What is responsible for darker skin?
Table of Contents
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-skin humans.
How did dark skin develop?
Evolution. Due to natural selection, people who lived in areas of intense sunlight developed dark skin colouration to protect against ultraviolet (UV) light, mainly to protect their body from folate depletion. Evolutionary pigmentation of the skin was caused by ultraviolet radiation of the sun.
Why is darker skin more common near the equator?
Darker skin absorbs more light and reflects less light, so it has lower reflectance than lighter skin, which absorbs less light and reflects more. At the equator (0 degrees latitude), the percent of light reflected by the skin is lowest. This shows that skin is darkest at the equator.
Is darker skin a dominant gene?
Inheritance of Skin Color
Each gene has two forms: dark skin allele (A, B, and C) and light skin allele (a, b, and c). Neither allele is completely dominant to the other, and heterozygotes exhibit an intermediate phenotype (incomplete dominance).
What determines the color of skin quizlet?
The pigment melanin, produced by melanocytes, is primarily responsible for skin color. Melanin comes in different shades of brown and black. Individuals with darker skin have darker, more abundant melanin, whereas fair-skinned individuals have a lighter shade of skin and less melanin.
Why did my skin get darker?
If your body makes too much melanin, your skin gets darker. Pregnancy, Addison’s disease, and sun exposure all can make your skin darker. If your body makes too little melanin, your skin gets lighter. Vitiligo is a condition that causes patches of light skin.
What is dark skin called?
synonyms for dark-skinned
black. tan. brunet. brunette.
How did different skin colors develop?
Theory held that darker skin had evolved in order to afford early humans—who had recently lost the cover of fur—a protection against skin cancer under the tropical sun. But skin cancers, Jablonski knew, almost always arise later in life, when an individual is past reproductive age.
What happened to skin color as early humans dispersed from the equator Why?
What happened to skin color as early humans dispersed from the equator? Why? The farther from the equator the lighter the skin color got. There wasn’t as much radiation to cause darker skin pigmentation.
Who has the darkest skin in Africa?
They found the darkest skin in the Nilo-Saharan pastoralist populations of eastern Africa, such as the Mursi and Surma, and the lightest skin in the San of southern Africa, as well as many shades in between, as in the Agaw people of Ethiopia.
Which skin Colour gene is dominant?
A genotype with all “dominant” capital genes (AABBCC) has the maximum amount of melanin and very dark skin.
Which factor is associated with darker skin quizlet?
the amount of melanin melanocytes produce. The more melanin produced, the darker the skin.
What factors can determine skin color?
Skin color varies considerably from individual to individual and is generally determined by the presence of melanocytes, carotene, oxygenated hemoglobin, and local blood flow. Melanocytes, found in the deep basal layer of the epidermis, contain brown granules called melanin.
What causes skin to change color?
Why is my face looking dark?
Our face skin produces more melanin compared to the rest of the body parts, so our face skin is generally a bit darker. The harmful rays of the sunlight can damage the melanin cells and as the face is more exposed to sunlight, it is the first to be impacted.
Why is my skin color getting darker?
Darker areas of skin (or an area that tans more easily) occurs when you have more melanin or overactive melanocytes. Bronzing of the skin may sometimes be mistaken for a suntan. This skin discoloration often develops slowly, starting at the elbows, knuckles, and knees and spreading from there.
What determines skin color?
Melanin
Melanin is produced by cells called melanocytes in the skin and is the primary determinant of skin color in people with darker skin.
What is the selective pressure for darker skin color quizlet?
One explanation is that the selective pressure for dark skin decreases as UV intensity decreases. At the same time there is selection for lighter skin to absorb more UV radiation, which is needed for vitamin D production.
What is the relationship of skin color to location?
These results indicate that human skin color is darker in the Southern Hemisphere than in the Northern Hemisphere at equivalent latitude. Recent research shows that UV radiation is higher in the Southern Hemisphere than in the Northern Hemisphere at similar latitude.
What is the darkest race?
From his research, he’s found that people from Senegal and the islands of Micronesia have some of the darkest skin tones in the world. That’s typical in countries close the equator, where the dark pigment melanin protects against UV damage from the sun’s rays.
Which country has the fairest skin?
It’s no secret that Irish people are some of the palest – if not the palest – people in the world. When the hot weather hits, and temperatures soar, the Irish feel it the most on that pale skin from the land of the Celts.
What genes affect skin color?
Additional associations with skin color were found in the OCA2 and HERC2 genes, which have been linked with skin, eye and hair color variation in Europeans, though the mutations identified are novel. Mutations in OCA2 also cause a form of albinism that is more common in Africans than in other populations.
Can fair parents have a dark baby?
The short answer is, yes! A couple can have a baby with a skin color that isn’t between their own. The long answer, though, is much more interesting. The long answer has to do with the parts of your DNA that give specific instructions for one small part of you.
What are the 3 main factors that contribute to the Colour of the skin?
Skin Color/Condition
Skin color varies considerably from individual to individual and is generally determined by the presence of melanocytes, carotene, oxygenated hemoglobin, and local blood flow. Melanocytes, found in the deep basal layer of the epidermis, contain brown granules called melanin.
Why is skin color dark in areas with high UV radiation quizlet?
People have darker skin that live closer to the equator because they need to produce more melanin to protect their cells from the intense UV rays. They also need to produce more melanin to protect the folate in their blood to protect their offspring.