melanin – BioQuakes

In a post written by Susan Eckert (teacher) and Shannon Huhn (student), the complex and complicated construct of race is broken down to reveal the true essence of society: genetics and the genetics of the skin.

Skin is one of the most important parts of our body. Firstly, as we studied in our immune system unit, we know that the skin protects us from sickness and from possible foreign invaders through the non-specific/innate bodily response. Specifically, however, our skin protects us from damage caused by UV light all because of melanin.

Although we may be familiar with this term as it is oftentimes involved in the conversation of race, research shows that the concept of race is not actually backed by science and the genetics of melanin. Before we can get into this conversation, we must learn about the science behind melanin. Importantly, our bodies contain cells called Melanocytes that produce the pigment called melanin. Through the process of melanogenesis, tyrosine is oxidized, which as we know from class means that it is losing electrons, and enzymes are utilized to produce two kinds of melanin: eumelanin which causes the skin to be dark, and phaeomelanin which causes the skin to be light. Although all of our bodies have the same amount of melanocytes, our skin color is determined by how much eumelanin and/or phaeomelanin is produced.

The production of eumelanin and phaeomelanin through oxidative and enzymatic processes.

With this knowledge, it is easier to engage in conversation on race. Throughout history, skin color has been used to fuel general racial inequalities. Darker skin, whose genetic purpose is to be able to absorb more light, has been wrongfully associated with inferiority while lighter skin, whose genetic purpose doesn’t involve absorbing a lot of light, has been associated with superiority, both based on the grounds of their appearances. Making these assumptions based solely on the physical color of the skin without acknowledging or thinking about the explanatory science should automatically negate these wrongful and incorrect accusations. According to Tiskoff and Kidd, “Humans are ∼98.8% similar to chimpanzees at the nucleotide level and are considerably more similar to each other”. Of course, we must take into consideration the confidence level and margin of error in this statistic, but nevertheless, the percentage is high, showing that race doesn’t make one inferior/superior as we are all essentially the same except for minor genes which produce specific skin colors. In general, it comes down to the production of pigments all based on necessary function.

We must combine what we know about melanin, genetics, skin, and race to move forward in our society. Although all are socially and genetically unique, we are all human on a genetic and molecular level. Conducting research and getting down to the science of various topics carries the necessary substantial weight to create change. What would you like to research next?

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

BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: melanin

Melanin: Breaking Down Barriers

The Biology of Skin Color

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