It’s easy to have an “us-vs-them” mentality today. It’s easy to see the division between people across political borders and easy to see them in our own communities and social groups. It’s impossible to not look at another human being and notice how they look different from other ones, or from ourselves.

What if I told you that skin pigmentation has nothing to do with who a person is, that race is nothing more than a social construct; that race does not exist in humans?

Race, in a biological context, refers to a subspecies that is isolated and ONLY breeds within this isolated population, causing a great deal of genetic similarities.

This is not the case in humans. While there are isolated groups of people, and many people choose to reproduce within their own culture and skin pigmentation, it is not enough to cause a new race of people. There are no subspecies of humans; differences in bone structure and skin pigmentation are an evolutionary coincidence, not caused by isolated reproductive events of subgroups of humans.

Why is it that humans have different skin pigmentation, why are we not one color?

Shortly after Darwin, scientists started to notice that people in select regions of the Earth have similar skin pigmentation, but that skin color still varied greatly outside of these regions. It was soon discovered that people who live (or whose ancestor’s lived) in areas with high amounts of UV rays, such as around the equator, tended to have darker skin pigmentation than those who lived in areas with relatively lower UV exposure. This is because, melanin, the brown pigment in the skin, helps to naturally protect people from the sun and ultra violet radiation.

Natural selection favored reproduction in people who were able to battle the ultra violet rays of the sun. Since UV radiation strips away folic acid, which is imperative to healthy fetuses, natural selection caused people who were pigmented darker to have greater reproductive success in areas of high UV radiation, and fostered healthy fetuses in lighter-pigmented people who lived in areas with low UV exposure.

Since some UV exposure is necessary to produce Vitamin D, lighter pigmented people had the reproductive advantage in these areas. They were able to have a balance between natural sun protection (less exposure) and enough sun to produce Vitamin D (less melanin).

However, this did not explain how some early people in low UV exposure areas were more darkly pigmented, but still were able to have relatively high reproductive success rates; the answer is seafood. For darkly-pigmented natives in the Arctic and Canada, the UV exposure was still low, but they were able to get Vitamin D from a diet rich in seafood, and were getting UV exposure from the reflection of ice.

Other genetic differences that we typically attribute to race, such as facial structure and bone density, have their origins in geographical human evolution as well. For instance, eye shape varies around the world because of climate differences. For instance, our ancestors that lived in northern Asia, developed their distinctive, narrow eye shape due to the need to protect the eye from cold and windy conditions.

Race then, is not a biological construct, as we are able to reproduce with any other willing human (with an exception for those who are unable to produce children for various genetic and health related reasons). Race is a social construct that we must begin to think outside of.