Consider, for a moment, how divisive skin color has seemingly always been. Now consider that our unique skin tones aren’t a matter of having melanin or not, as if often thought. Everyone has melanin. Rather, the differences in our skin tones are the result of the amount, type, size, and distribution of melanin our bodies make – which is determined by our genetics, by the way.
What is melanin, exactly?
To better appreciate just how subtle the differences are, let’s backtrack and define what melanin is. It’s created by cells called melanocytes, of which we all have roughly the same amount.
We’re born with all of our melanocytes, but they don’t start to function until the second trimester of development. That’s why newborn skin can darken over the first few months. It’s most apparent in darker skin tones.
The skin color that ultimately develops is dictated by the ratios of two kinds of melanin: eumelanin, which manifests as brown and black pigment, and pheomelanin, which appears as yellow and red. How much of each type of melanin is produced accounts for the skin color variances among us.
But not just us. Melanin also creates the beautiful colors of butterflies and bird feathers. Traces of melanin have also been found in dinosaur fossils.
Melanin’s not just behind our skin color
Melanin also isn’t only responsible for the color of our skin. Anywhere you see pigment on your body (or a lack thereof), it’s a direct result of melanin.
The color of your eyes, for example, was determined by genetics. It also correlates to the amount and type of melanin in the front layer of your irises. Brown eyes have the most melanin. Blue eyes have none at all. Blue eyes actually get their color the same way water and the sky get theirs: by scattering light so that blue reflects back out.
Your hair follicles also contain melanocytes. The kind of melanin that comes from those melanocytes – and, in turn, your hair color – also boils down to genetics. Just like your skin, the ratio of eumelanin that’s produced dictates whether you have darker hair or lighter hair. (Fun fact: It’s estimated that more than 90% people worldwide have black or brown hair.)
Finally, freckles can’t turn into skin cancer, but they can signal your susceptibility to developing it. They can darken and, potentially, turn into hyperpigmentation when melanocytes overproduce melanin following sun exposure.