KNOWLEDGE YOU CAN USE

KNOWLEDGE YOU CAN USE
Do Racial Differences Exist on a Genetic Level?

In a fraction of a second, we are aware of someone’s size, gender, approximate age—and race. But what is race? Does race have biological meaning? And can humans be categorized into groups that can scientifically be called races?

Question 10.9

Q: What is race, biologically speaking? The biological species concept hinges on a straightforward question: can two individuals interbreed under natural conditions? The concept of race, conversely, is not straightforward. Some biologists have proposed that races are groups of interbreeding populations that have different and distinct traits but are reproductively compatible. But it is important to note that, in humans, beyond phylogenetic distinctions, religion, culture, ethnicity, and geography are common aspects of many legal, social, and political conceptions of race. So do such social constructions of “race” reflect meaningful divisions?

Question 10.10

Q: What do human racial groupings reflect? Are blacks and whites genetically different? The answer is obviously yes; black-skin alleles differ from white-skin alleles. Moreover, the prevalence of some genetic diseases varies by race and ethnicity. Sickle-cell anemia, for example, is relatively common among Africans and Southeast Asians because the genes that cause it also improve a person’s resistance to malaria, a disease prevalent in Africa and Southeast Asia.

Yet Africans from the southernmost part of the continent have no greater risk of sickle-cell anemia than do the Japanese, because malaria is similarly rare in both of their homelands. Should we use this trait rather than skin color when determining a person’s race? If we did, southern Africans would be grouped with the Japanese and northern Africans with southern Asians (who share their genetic resistance to malaria and the higher risk of sickle-cell anemia).

This observation reveals an important problem with racial groupings, one that DNA sequence comparisons also show: similarity in skin color between two people doesn’t tell you anything about overall genetic similarity. There is, for example, a huge variation in blood type among Africans: some are type O, some AB, others A or B. But the same goes for any population in the world, Asians and Turks, Russians and Spaniards. Yet we do not group people according to blood type or any other physiological and biochemical variations.

Question 10.11

Q: What is the future of race? Racial groupings such as “Hispanic” or “black” or “Asian” do not reflect consistent genetic differences. Still, race remains an important part of individual, social, cultural, and ethnic identity for many, and its use is mandated by federal agencies. For these reasons, it will remain a powerful social construct, even as scientific consensus emerges that racial groupings do not reflect meaningful genetic distinctions.

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