What is the advantage of having darker skin near the equator?
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.
What does the equator do with skin color?
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. As latitude increases, the amount of light reflected by the skin increases. This shows that skin gets lighter farther from the equator.
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.
Is skin color an adaptation?
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 darker skin more protected from the sun?
Darker skin has more protection from the sun because it contains higher levels of melanin. This is the pigment that gives the skin its color and helps protect the cells from some forms of sun damage. In people with lighter shades of dark skin, melanin is not fully protective. For this reason, they may still burn.
How does melanin protect the skin?
The outer layer of the skin has cells that contain the pigment melanin. Melanin protects skin from the sun’s ultraviolet rays. These can burn the skin and reduce its elasticity, leading to premature aging. People tan because sunlight causes the skin to produce more melanin and darken.
Does distance from equator affect skin color?
(SAVANNAH, GA) In general, the closer to the equator an individual lives, the higher the melanin content in their skin. White skin appeared only 20,000 to 50,000 years ago, as people migrated to cooler climates.
What determines skin color?
Melanin content of skin is the main determining factor of skin and hair colour; hair is considered a form of skin with regards to pigmentation. Melanin is synthesized by melanosomes found in skin cells called melanocytes.
How is skin color an adaptation in human populations?
In global populations, skin color is highly correlated with latitude, and fundamentally, the distribution of ultraviolet (UV) radiation (Fig. These cases show the similarities and differences of mechanisms of skin color adaptation across populations, and provide some insights into human evolutionary history.
How does sunlight affect skin color?
Why is a person with a darker complexion more protected from the sun’s UV rays compared to a person with fair complexion?
Melanin helps block out damaging UV rays up to a point, which is why people with naturally darker skin are less likely to get sunburned, while people with lighter skin are more likely to burn.
Does more melanin protect you from the sun?
Melanin protects skin from the sun’s ultraviolet rays. These can burn the skin and reduce its elasticity, leading to premature aging. People tan because sunlight causes the skin to produce more melanin and darken. But too much ultraviolet, or UV, exposure can cause sunburn.
How does the equator affect your skin color?
For the most part, the further you get from the equator, the lighter skin becomes. This is not always the case however. For example, Inuit people in Canada, and people living in the arctic tend to have darker skin. This is because a large amount of sunlight is reflected off the white tundra, and can have an impact on folic acid levels.
What are the advantages of having dark skin?
Dark skin is an advantage if one lives close to the equator, because the melanin (brown pigment) blocks harmful ultraviolet solar radiation. I live in a very sunny place at 26 degrees north latitude (barely north of the tropics), and I often wish I had more skin pigment.
How did the distribution of skin color change over time?
Before the mass global migrations of people during the last 500 years, dark skin color was mostly concentrated in the southern hemisphere near the equator and light color progressively increased northwards away from the equator, as illustrated in the map. There is a strong correlation between skin color distribution and sunlight intensity.
Is skin color an adaptation to sunlight?
Human skin color is highly variable around the world. Recent research has suggested that skin color developed as an adaptation to cope with the damaging effects of sunlight.