Do people near the equator have darker skin?

People from tropical regions of the world at or near the equator generally have darker skin than people who live in temperate regions farther from the equator, because variation in human skin color is closely related to geographic variation in solar radiation.

Why was dark skin selected for in regions close to the equator?

The darker skin of peoples who lived closer to the equator was important in preventing folate deficiency. 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.

What is the selective pressure for lighter skin color?

6. Indigenous populations in low-UV environments tend to have lighter skin tones. One hypothesis is that, in low-UV environments, the selective pressure for dark skin is low. Instead, there is selective pressure for lighter skin, which absorbs more UV radiation, since UV is needed for vitamin D production.

How can skin color be an adaptation to the environment?

The evolution of humans is written on our skin. Beyond an identity signature, human skin color represents an example on how our species has been capable to adapt to different environments. The melanin determines skin pigmentation level (it is responsible for tanning) and acts as a protective barrier.

What is fair skin tone?

The term “fair skin” is typically used to describe a human skin color that is usually considered the lightest natural shade. People with this sort of skin are typically of Caucasian or East Asian descent, though it can occur in people from various racial and ethnic backgrounds.

Does the equator determine skin color?

Previous studies of human skin color have shown a strong relationship between skin color and distance from the equator, which has been interpreted as a link between skin color, latitude, and the intensity of ultraviolet radiation. For both males and females, skin reflectance (\%) is lowest at the equator (darkest skin).

Why is skin color dark in areas with high UV radiation quizlet?

Darker skin is more prevalent in high-UV areas. 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 selective pressure for lighter skin color quizlet?

Human populations in low-UV environments tend to have more lightly pigmented skin. 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 type of adaptation is skin color?

Skin color is a well-recognized adaptive trait and has been studied extensively in humans. Understanding the genetic basis of adaptation of skin color in various populations has many implications in human evolution and medicine.

Why is fair skin?

The characteristic of fair skin, red hair, and freckling is associated with high amount of pheomelanin, little amounts of eumelanin. This phenotype is caused by a loss-of-function mutation in the melanocortin 1 receptor (MC1R) gene.

Why is skin tone different around the equator?

There’s a convincing explanation for why human skin tone varies as a global gradient, with the darkest populations around the equator and the lightest ones near the poles. Put simply, dark complexion is advantageous in sunnier places, whereas fair skin fairs better in regions with less sun.

How did humans evolve to be fair skinned?

When the ancestors of modern man separated from apes, they were covered in hair. Little UV light reached their skin and as a result, anthropologists believe they were fair skinned. As modern humans evolved however, their body hair became finer and thinner, leaving their skin more exposed to the equatorial sun.

Why does nature have selected people with darker skin?

Nature has selected for people with darker skin in tropical latitudes, especially in nonforested regions, where ultraviolet radiation from the sun is usually the most intense. Melanin acts as a protective biological shield against ultraviolet radiation.

Why does Poland have so many dark-skinned people?

Over the centuries Poland received immigrants from far away lands such as Jews, Gypsies, and Armenians who are dark haired/skinned. And overtime they mixed with poles!