The Science of Skin Tones
(Audience: adults uneducated on the topic of skin and melanin with little/no previous knowledge)
The young boy walked into the crowd with his head held high, attempting to hide the fear that was rising within. The adults around him looked down upon him, sneering, surprised that he even dares walk so confidently in their presence. The little boy had done nothing wrong: He was just born with dark skin. In the early twentieth century, scenes like this one were not uncommon in many parts of America. This boy, like many others, looked different from the majority and therefore was different in the eyes of many. However, the skin tone that reveals itself does little justice to show just how similar we all are underneath. There are many factors that play into the skin tone that you are born with, including ancestral heritage, melanin production by cells called melanocytes, and simple genetics. The human body is an extremely complex system, and we are still continuing to learn more about how our bodies work every day. The real question is: How much do you know about the color of your own skin?
Similar to food coloring in a glass of water, our skin is colored by certain pigments that are produced naturally by our bodies. This pigment, melanin, is produced by a group of skin cells called melanocytes. According to Britannica editor Kara Rogers, the definition of a melanocyte is as follows: “[a] specialized skin cell that produces the protective skin-darkening pigment melanin.” Everyone has the same number of these melanocytes in their bodies, the only difference is how much and what type of melanin is produced by the cells. There are two different types of melanin: eumelanin and phaeomelanin. The first type is the darker-brown pigment, while the second is a much lighter pigment that appears yellowish or pale-red in color (Rogers). The type of melanin that is produced by your skin cells and the different amounts produced of each will determine what your specific skin tone is.
Melanin, a protective pigment, is a “natural sunscreen” produced by our bodies in order to protect our cells from the harmful effects of UV rays (“Modern Human Diversity…”). Too much ultraviolet radiation, like too much of any other radiation, is not good for or bodies. An excessive amount of UV exposure to skin can lead to mutations in the skin such as skin cancer, and that is why your mom may have told you as a kid to put on more sunscreen even though you were so sure that you were not getting any sunburn. In order to prevent too much exposure and keep the UV ray absorption balanced, the human body evolved to produce more/less melanin to adapt to different living conditions. Those who lived closer to the equator were facing stronger UV rays from the sun and over time developed darker skin tones (aka increased melanin production) to better protect their bodies from the power of the sun (“Modern Human Diversity…”). The opposite happened with those who lived farther from the equator, and this process occurred during the vast period of early human evolution. This adaptation allowed for a reasonable balance of UV radiation absorption to be maintained, therefore preventing skin cell mutation and ensuring effective vitamin D formation.
Like every part of the body, sometimes the melanocytes do not function properly or effectively. This can result in different skin conditions including vitiligo and albinism. Vitiligo occurs when some of the melanocytes in the body are not able to produce melanin, resulting in patches of pigment-free skin. This can occur in anyone, no matter what their original skin tone is. Similarly, albinism is also associated with a decrease in melanin production. However, this does not occur in patches but rather all over the body. In addition, those with albinism may produce no melanin at all. Sometimes it is easy to spot someone with albinism due to their extremely pale skin and light hair, although it is not always this simple. According to a source from NHS, some diagnosed with albinism may have ginger or brunette hair depending on the amount of melanin produced by their melanocytes (“Albinism”). Those with albinism still have the same number of melanocytes as everyone else, they just function differently, leading to different pigmentation of a person’s skin and hair.
This world is full of billions of people, each with their own unique skin tone. These different skin tones are due to the production of melanin by melanocytes. Everyone has the same number of melanocytes, and these skin cells function in ways that give us all our own unique appearances. Since scientists have proven that the production of melanin was a protective mechanism carried out to help humans better adapt to their environments, it is our ancestors, along with genetics and heredity, that gives us the skin tone we are born with (“Modern Human Diversity…”). This color may be different for each person, but underneath that skin we all have the same cells working together to make sure our bodies are safe and healthy.
Works Cited
“Albinism.” Nhs Choices, NHS, 30 Nov. 2020, https://www.nhs.uk/conditions/albinism/. Accessed 29 September 2021.
“Modern Human Diversity – Skin Color.” The Smithsonian Institution’s Human Origins Program, 17 June 2020, https://humanorigins.si.edu/evidence/genetics/human-skin-color-variation/modern-human-diversity-skin-color. Accessed 29 September 2021.
Rogers, Kara. “Melanocyte.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 6 May 2009, https://www.britannica.com/science/melanocyte. Accessed 29 September 2021.