Post by Minna Krejci
The image above — showing a sample of a 2009 exhibition in Brazil called Naucier, by French artist Pierre David — was meant to be a statement on racism. The idea was to show what it means to be reduced to just the color of your skin. Literally.
Perhaps in a more positive sense, Naucier also provides an interesting way to observe and appreciate the wide variety of skin tones that exist across our species. Nina Jablonski, a professor of anthropology at Penn State, fittingly refers to this variety as the “beautiful sepia rainbow that defines humanity.”
Watch Jablonski’s TED talk below on the evolution of skin color:
I first saw this video last year, when it was played at a TEDx program (an independently organized version of the TED talks) that focused on issues of identity, particularly with respect to sex and race. The talks addressed how we need to be moving our thinking forward in these areas to keep up with contributions from modern science and technology.
In her talk, Jablonski explains Darwin’s claim that skin color has nothing to do with climate, and this this claim was simply a result of a lack of appropriate evidence. Now, we have that evidence, thanks to NASA satellite imagery:
The NASA data revealed an unmistakeable correlation between global ultraviolet measurements and published data on skin color in indigenous populations from countries across the world: the weaker the ultraviolet light, the fairer the skin.
Here is Jablonski’s explanation of how this happened:
- The origin of man is in Africa, where there is ample exposure to ultraviolet light. In order to protect the skin from damage from UV radiation (which includes the risk of cancer and the breakdown of folate in the body) the body evolved to produce the pigment melanin, a natural sunscreen. Apparently we were first all darkly pigmented, 1.5-2 million years ago.
- Then we moved, several times, to spread our species across the globe. Humans were ending up in areas with much less access to ultraviolet light. While the harmful effects of UV radiation are well known, the importance tends to be less talked about: UV-B catalyzes the production of Vitamin D in our bodies, which is an important hormone for our immune systems, mental health, and more.
- Humans in low-UV areas then evolved, by natural selection, to have less melanin in our skin, in order to have more access to the limited supply of UV-B radiation. This gave rise to, as mentioned earlier, the “beautiful sepia rainbow that defines humanity.”
So what does this mean today? We definitely see plenty of people with darker pigmented skin living in northern climates, as well as people with lighter pigmentation living near the equator. From a health and wellness standpoint, this means that we’re living in a lot of the wrong areas, a lot of the time! In other words:
- People with lighter skin who have high exposure to UV radiation are more at risk for skin cancer and the breakdown of folate. (Fortunately, doctors tend to be quite good at making us aware of these risks and explaining the benefits of sunscreen.)
- People with darker skin who have low exposure to UV radiation (as a result of high latitudes, desk jobs, etc.) are more at risk for Vitamin D deficiency. This can have deleterious effects on bones, immune systems, mood, and mental health.
So there can actually some serious health benefits to not wearing sunscreen? Vitamin D can be also taken as a supplement, although there does also appear to be some debate over what the daily recommended intake should be. (By the way, I highly recommend these gummy vitamins — they’re seriously delicious.)
Jablonski closes her talk with the following somewhat dramatic statement: “You have the evolution of the history of our species, part of it, written in your skin… You are the products of evolution.” Might this change the way people think about skin color, at least a bit?