It’s a hot summer day and you are relaxing by the pool. Ever wonder why your skin gets darker or tanner when doing so? It’s because of melanin!
Melanin is a skin pigment that can be found in humans, animals, and most organisms. It is responsible for making hair, skin, and eyes appear darker. Melanin exists in two forms: eumelanin and pheomelanin. Eumelanin is black or brown pigment and pheomelanin is red or yellow pigment in one’s skin tone.
Different Skin Colors
When you are exposed to the sun, more melanin is produced. “In human skin, melanin pigments are synthesized in organelles called melanosomes that are found in specialized cells called melanocytes in the skin epidermis.” In order for melanocytes to produce melanin, a receptor protein called MC1R, found in the melanocyte cell membrane must be activated by melanocyte-stimulating hormone (MSH) which is secreted by the pituitary gland in response to exposure from UV light. Once MC1R is activated, it triggers the production of release of cAMP and as we learned in class, this triggers a cell signaling pathway ending with the release of eumelanin, making our skin appear darker.
A short additional fact is that melanin protects us from skin cancer. Melanin can absorb the UV rays and block them from reaching and damaging the DNA within one’s melanocytes. In this case, melanin acts as “a protective agent in the skin” joining your first line of defense to protect you against pathogens or in this case to protect you against the damaging UV rays. There are three types of skin cancer: basal cell carcinoma, squamous cell carcinoma, and melanoma.
A person’s skin color depends on the amount and type of melanin (eumelanin or pheomelanin) present in one’s skin. Genetically speaking, “people with naturally darkly pigmented skin have melanosomes that are large and filled with eumelanin” (biointeractive.org). As discussed above, there is a huge biological importance of melanin; without it, humans wouldn’t have a protective skin barrier against the UV rays emitted by the earth, but throughout history the importance of melanin has been placed to the side due to the idea of race or more specially racial superiority based on ones skin tone being introduced into the conversation.
In short, while there is a biological basis of skin color, there is no biological basis or scientific explanation of race. Although it has been attempted, by Samuel Morton in the 1800s when he compared the brain sizes of the five racial groups or by Dr. Menegele during WWII when he measured facial features of the Jewish people, it is challenging to use science to support the concept of race. In fact, there are more differences within the “determined” races (African, European, Asian, Oceania, Native American) than between them! No specific amount of melanin, or any trademark alleles for that matter, specify a race. It is important to look at and understand science and evolution- looking at where people come from and why they have that skin color that they do based on melanin and weather conditions around them. It is important to take into account how we have evolved into unique humans, even though 99.6 – 99.8% of our genetic material is identical. It is important to educate ourselves about why we are the way we are and how evolution has impacted that, not how groups of people throughout history have tried to give an racist explanation for it.
Skin Colors Found Around the World
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