Hello and welcome back to another fun learning adventure! Today we are going to talk about humans! Specifically, we are going to delve into the science behind why we come in so many different colors. From the palest white to the deepest ebony, why are we the color that we are?
First and foremost, let’s talk about what gives skin its color. There is a brown pigment called melanin found in cells called melanocytes. Melanocytes are found in the skin and hair and give each their various colors. The amount of melanin produced by these cells determines how light or dark your skin or hair color is. The difference in melanin levels is an adaptive trait that correlates with UV radiation and geographical location.
What is the purpose of melanin, you may be asking? Melanin is basically your body’s natural sunscreen. While some UV exposure is necessary for vitamin D production in the body, overexposure can be damaging to the body. Being exposed to too much UV radiation can cause cancer, strip the body of folic acid, and cause damage to your skin cells which can lead to premature skin aging. Melanin helps to filter out some of those damaging UV rays to protect your body.
So, how does your, or more likely your ancestors’, geographical location influence the amount of melanin present in your skin cells? Depending on how close to or far away from the equator you are, the more or less UV exposure you will have. The closer you are to the equator, the more UV rays you will be exposed to because there is more direct sunlight. So, the closer your ancestors were to the equator, the more melanin you are likely to have. In the same respect, the farther away from the equator, the less melanin you are likely to have. Because there are fewer UV rays, you require less protection and need more rays to penetrate so your body can produce enough vitamin D. Now, there are some exceptions to this rule. Some indigenous populations found near the arctic who eat large amounts of seafood, which is high in vitamin D, have retained darker skin tones. They also need more protection during the winter months when a lot of UV rays are reflected back by the snow and ice.
Thank you for learning with me! It should go without saying, but EVERY color of skin is absolutely beautiful and no one should be judged based on the color of their skin. We are all just different shades of the same beautiful brown. Do you have any questions about the wonderful spectrum of skin color and melanin levels? Leave them below!
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