Despite all belonging to the Homo sapiens family, human races bear distinct dissimilarities in appearance, language form, among other noticeable traits. That is because of microevolution, the change in allele frequencies occurring over time within the human population. Ideally, microevolution is propagated by four processes – mutation, natural selection, genetic drift, and genetic flow (Kolbert, 2018). That is to say, depending on where the initial members of the homo sapiens group found habitat, their skins (and skull structures) underwent DNA tweaks to suit them to the varying conditions such as the hot African sun or icy Antarctic weather.
On skin colour, many genes control the effect of melanin on the human skin, and their selective variation in line with each race’s native geography accounts for the distinctive differences. For instance, the National geographic observes that MFSD12, the gene mutation responsible for the light-to-dark modification, occurred 996,000 years ago, resulting in the “yellow” pigmentation seen in South Asiana and Australo-Melanesians (Kolbert, 2018). On the other hand, HERC2, a darker variation of the MFSD12, occurred 345,000 years ago, resulting in darker skin complexions observed in Black Africans such as Ethiopians and Tanzanians. Majorly, the mutations happened to promote faster Vitamin D synthesis and protection from harmful UV rays. Unaltered versions of genes such as SLC24A5 resulted in the “white” pigmentations seen in the Caucasians.
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The same reasoning can be extended to explain eye pigmentation, hair colour, height, and differences in language forms. However, some of these are a consequence of the initial evolution discussed above. Others resulted from the unique diets the communities found in their new habitats. For instance, the Inuit people, who inhabited the Arctic regions of Greenland, Canada, and Alaska, adopted a marine diet whose richness in fatty acids induced genetic tweaks in their DNA, resulting in longevity and more muscular body builds (Chen, 2015). Thus, we do not look alike because of microevolution, which drives changes in DNA to suit our habitat’s ecological demands.
References
Chen, A. (2015, September 17). “The Secret to The Inuit High-Fat Diet May Be Good Genes.” NPR . Available at https://www.npr.org/sections/thesalt/2015/09/17/441169188/the-secret-to-the-inuit-high-fat-diet-may-be-good-genes
Kolbert, E. (2018, March 12). “There’s No Scientific Basis for Race—It's a Made-Up Label.” The National Geographic. Available at https://www.nationalgeographic.com/magazine/2018/04/race-genetics-science-africa/
