Puzzle Pieces of History: Section 1

The Depth of Darkness: Exploring the Wonders of Melanin

Despite efforts to avoid it, discussing skin color can often become a sensitive topic. While some shy away from the subject, others actively engage in it. Understanding skin color could save someone’s life. Dr. Keith Cheng’s “lab’s specific work is aimed at increasing understanding of the basis of phenotypic variability, particularly as it may impact cancer; basic mechanisms underlying the relationship between human skin pigmentation and skin cancer.” -Penn State Cancer Institute

Understanding Melanin: Its Role and Importance

Melanin is a pigment that gives color to our skin, hair, and eyes. It is produced by cells in our skin and helps protect us from the harmful effects of the sun’s UV rays. Humans have three forms of melanin: eumelanin, pheomelanin, and neuromelanin.

Eumelanin, a brown-to-black pigment, is the most prevalent form of melanin, it is the black form of melanin. It is created through melanogenesis, which involves the oxidation of the amino acid tyrosine and subsequent polymerization. Eumelanin protects against UV radiation by effectively absorbing light and dissipating over 99.9% of absorbed UV radiation. This property allows eumelanin to safeguard skin cells from damage caused by UVA and UVB radiation, reducing the risk of folate depletion and skin degradation.

Pheomelanin is a melanin pigment that has a reddish-yellow color and contains sulfur. It is created when melanocytes malfunction due to a recessive gene and is a cysteine-derivative with polybenzothiazine portions that contribute to the red or yellow tint seen in some skin and hair colors. In addition, Pheomelanin is responsible for the pinkish hue found in areas such as the lips, nipples, vagina, and penis glans.

Neuromelanin is a dark melanin pigment found predominantly in some dopaminergic neurons of the human brain.

Unveiling the Land Touched by Sunlight

As individuals reside closer to the equator, their complexion tends to be darker due to increased melanin production. But then, when humans migrated away from the equator, their skin tones gradually became lighter. Numerous genes, including TYR, OCA2, and MC1R, influence skin color variation. Among them, SLC24A5, extensively researched and funded by Dr. Keith Cheng, specifically impacts pigmentation by decreasing melanin production, ultimately leading to lighter skin tones.

The SLC24A5 gene variant is believed to have first appeared and spread in populations of European ancestry around 6-15,000 years ago. There are many theories on how this genetic change occurred, but there is no denying that SLC24A5 is a genetic mutation.

Africa is the epitome of genetic diversity, the birthplace of anatomically modern humans (Homo sapiens sapiens). As individuals migrated from Africa to what we now recognize as Europe, the activation of the SLC24A5 gene occurred, gradually leading to the emergence of lighter skin tones associated with populations in other regions and worldwide.

Redefining Black Skin

According to Oxford Languages, the term “black” encompasses various definitions. However, specifically when referring to a group of people, it often denotes individuals with dark skin, particularly those of sub-Saharan African descent. Additionally, one of the definitions also includes the concept of the color or pigment black. The black pigment can range from light brown to very dark brown.

When identifying individuals, skin color is often used as a visual cue. However, it is essential to note that not all individuals with light brown or dark brown skin identify as black. There are various reasons behind this perspective, and it is crucial to respect their self-identification. However, referring to every light-brown to dark-skinned individual as black can be considered disrespectful and disregards the diversity of their experiences and cultural backgrounds.

In contemporary discussions, confident individuals, including Zahi Hawass, an Egyptian archaeologist, challenge the prevailing belief that ancient Egyptians were primarily of black African descent, despite numerous depictions depicting individuals with varying shades of brown skin. The debate regarding the classification of black skin remains ongoing. Nonetheless, it is unquestionable that black skin encompasses a broad spectrum of tones, ranging from light brown to very dark brown. The rich diversity within black skin should be acknowledged and respected. Therefore, let me conclude by saying

Knowledge is Power