A lesson in race, for those who need it

This past semester I had the privilege of being an adjunct lecturer for a college-level general biology course. In my unit on human evolution, I taught about human diversity and skin color. At first I was intimidated; how was I going to talk about this incredibly complex topic with a class of 18- to 20-year-olds? I decided the best way to talk about race was to start with the bare facts of biology. I hope that the following (albeit reduced) explanation may help some readers understand why the ideals of white supremacy are both factually and morally wrong.

All human genes are a sequence of four different molecules. They are adenosine, thymine, cytosine and guanine. Every gene that a human being has — and every living organism has, for that matter — is made up of just these four molecules in different sequences. The human genome, the summation of these letter sequences, is 3 billion molecules long. If it were a book, it would have 200,000 pages in it, it would be as tall as the Washington monument (555 feet tall) and would take about 9.5 years to read aloud. Any given human is only 0.1% genetically different from another human. This means if we were to compare the 200,000-page books of sequences from two strangers, 200 pages of this book would vary (footnote 1).

In the eyes of biology, there is no such thing as race because it is a social construct. The reason we see such diversity in human skin color is because of environmental factors and slight changes in certain genes.

When the human species, Homo sapiens, first emerged in Africa 200,000 years ago, most individuals had dark skin. This was because they had a gene that resulted in their skin having lots of melanin, a pigment that helps protect skin cells from UV radiation. Living in equatorial Africa, this helped prevent skin cancer and early death. Individuals with lots of melanin could, theoretically, live longer and be able to reproduce, passing their genes onto their offspring because they were less likely to die of cancer at a young age.

As humans migrated across the planet and populations grew, individuals were born that had random small alterations, or mutations, in their melanin-producing gene. White skin, for example, is caused by having a mutation in the melanin gene which reduces its concentration in our cells. This mutation was more common in humans who had migrated away from the equator, to the north. At these higher latitudes, UV radiation is not as intense, thus the threat of skin cancer is not as great. It is also thought that having white skin in these more northern populations was advantageous because it helped individuals produce more vitamin D. Simply put, not having lots of melanin in these low-UV-radiation environments did not mean you would perish before producing offspring and actually helped you produce more vitamin D (2). This combination of random mutations and migration patterns in early humans is the basis for the modern-day concept of race.

When we look at what race is in the light of biology, the idea that one is superior to the other, that they should not mix, or that one must be conquered is meaningless. One race is not favored above the rest because there are no biologically defined races, just genetic diversity. Humans are 99.9% identical, no matter where they come from in the world, so why should 0.1% determine their worth? Why should a single change in a gene determine your socio-economic standing? Why should it mean you are more likely to be brutalized by others? Why can’t that 0.1% difference be celebrated as the beauty and diversity that it really is? It’s about time we start celebrating these differences in our appearances and start treating each other with the one thing we all share, our humanity.

Madeline Clark lives in Saranac Lake.


1. Shuster, M., Vigna, J., Sinha, G., Tontonoz, M., and Kilburn, K.S. (2018). “Biology for a changing world” (3rd ed.). W.H. Freeman & Company.

2. Canfield, V.A., Berg, A., Peckins, S., Wentzel, S.M., Ang, K.C., Oppenheimer, S., and Cheng, K.C. (2013). “Molecular Phylogeography of a human autosomal skin color locus under natural selection.” G3: Genes|Genomes|Genetics, 3(11), 2059-2067. https://doi.org/10.1534/g3.113.007484


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