There's No Such Thing as Race... Or Is There?

Today we're going to take a deeper dive into one of the most popular themes in science in recent years: the recognition that genetically, there is no such thing as race. Nothing in our DNA identifies us as Caucasian, Mongoloid, or Negroid, or lends any support to the idea that any of those classifications might exist at all. No gene or combination of genes is unique to any race. Race, says today's common wisdom, is merely a "social construct" — it is a way we look at each other, make a snap judgement based on some obvious traits, and apply a label. This seems like a simple enough resolution of the question, and is not especially controversial. So why, then, does the question persist?

Humans are a relatively young species, and there is much less diversity among us than among other species. Consider how much chimpanzees look alike to us; and then consider that any two chimpanzees have about twice as many genetic differences between them than do two humans of greatly different size, shape, and color. Genetically, we are the most homogenous of any primate. Turns out that all those perceived differences between us don't go very deep at all. But that hasn't stopped some people from trying to make it seem so.

The classical definition of the races, which you can find repeated all over the Internet, comes from an old German encyclopedia, the Meyers Konversations-Lexikon, 4th edition. It contrasts the skull, face, and nose shapes of Caucasians, Mongoloids, and Negroids. Caucasians, for example, are said to have long, narrow, high noses; Mongoloids have wide, short faces with projecting cheekbones; and Negroids have long skulls with prominent jaws. Reading the descriptions, and living in the melting pot of California, what's clear to me is that I don't really know anyone who matches any Meyers racial description.

But this chasm between today's reality and obsolete racial descriptions is backed up by evidence that's a lot more substantial than my personal observation. In today's science, we don't speak so much of races as we do of populations, loosely defined as a group with a certain frequency of certain alleles relative to others. To understand what that means, let's go through some brief definitions.

An allele is one alternative form of a gene that usually has two possible variations, and usually one is dominant and one is recessive. A familiar example is one difference between Scandinavians and Asians: we're likely to find a lot of the blue-eye alleles in the Scandinavian population, and a lot of the brown-eye alleles in the Asian population. The relative frequency of various alleles in different populations is what makes the populations look distinct from one another. The allele for red hair is found a lot in Ireland. Freckles, cleft chins, dimples, blood type, color blindness, earlobe shape, and countless other traits are all controlled by alleles.

Populations, defined this way, are not distinct from one another. They blend into each other. Populations are not bounded by lines, but by clines, which are gradations. A population as a whole has a certain frequency of alleles, but any given individual is somewhere along a cline, and it is difficult or impossible to tell which population he might be from.

A genotype is your genetic fingerprint. It's the sum of all the inheritable genetic variations that make you an individual unique from everyone else. Your genotype is the dataset that we'd get by sequencing your genome.

Your phenotype, on the other hand, is a broader description. It includes all the observable traits that your genotype has conferred upon you, and also your learned behaviors and other environmental influences. Your phenotype is that combination of nature and nurture that makes you not just what you are, but who you are.

Genotype and phenotype can also apply to a single trait. A person's genotype may include several alleles affecting eye color; his phenotype is the color that finally manifests itself.

It's this difference between genotype and phenotype that has driven some apparent scientific support for racial stereotyping. One of the most dramatic examples was the 1994 book The Bell Curve: Intelligence and Class Structure in American Life. One of the points made in the book was that there are racial differences in intelligence; a point which, it turns out, is indeed supported by the data; but, importantly, only if race did exist. The book triggered enormous controversy, both in favor of and opposed to its conclusions. Any useful discussion of this is well beyond the scope of a Skeptoid episode, but we can make one point. While the authors argued for a genotypical basis for intelligence, most criticism — and most of today's scientists in the field — would argue for a phenotypical basis. When you're born poor, badly educated, perhaps raised with English as a second language, drop out of school to join a gang — sounds like one or more familiar racial stereotypes, doesn't it? — you are indeed more likely to score badly on an intelligence test. The evidence that we have today suggests that this is due to phenotype, which incorporates environmental pressures such as life experience and education.

Outside of science, the idea of race has, quite obviously, been responsible for a massive proportion of all the bad things in human history. Nearly everyone wants to discard it completely, but we can't, because we find we still have needs for it. Race comes into play when we design programs intended to undo some of the harm that was done to certain populations. But perhaps least controversially, and most complicated, is the fact that we still need it for the medical and biological sciences.

A fundamental difference between race and ancestry is that ancestry is a bottom-up process, while race is a top-down classification. Except for their immediate siblings, every person on Earth has a different ancestry, and each of us has become — through countless generations — increasingly diversified from everyone else. Our ancestry includes all that we are, and it is unique to us. Race, however, discounts the intricacies of ancestry and instead takes a single superficial glance at a few basic traits, then rubber stamps us with one of a very few categories. Race is a label that dismisses a massive amount of data, so it would seem to be an idea that's not of very much use to biologists.

Yet it is still used, and used a lot. The idea of race has hung on for so long in biological circles because many diseases are highly correlated with race. We had to understand why this is, in order to understand the disease and develop a way to fight it. So, even though it was politically incorrect, studying cystic fibrosis in "white people" or sickle cell anemia in "black people" made a certain amount of sense. Researchers and even healthcare providers still often ask patients to identify themselves by race, because the idea has always been that it's a useful predictor of susceptibility to certain diseases, or of reaction to certain treatments.

This is largely wrong, but it isn't entirely wrong. People who appear to be of the same race probably do share many of the same alleles, thus they're also more likely to share the same disease-related markers. This is often the case with people from the center of a population, such as people with a deep Chinese heritage whose ancestors have lived in the same area for a thousand years. It's far less likely to be the case in a country like the United States, where everyone's ancestors came from populations all over the globe, each of whom followed a different braid of intermarriage to get there. So the likelihood is far less, but even people in the United States with similar physical appearances are more likely to share disease markers than are two people with different racial identifications.

This limited utility of a "race" classification in biology is becoming more limited with each generation, as populations become increasingly blended. About all it has going for it is convenience due to nearly everyone's ability to self-report. But the convenience of access to bad data is not necessarily a merit.

The problem is that we don't always have access to good data. Many of the alleles related to diseases haven't yet been identified, so there are still a lot of cases where we can't look at someone's genotype and know their susceptibility to a certain disease. But in some of these cases, we can still look at them and say something like "Hmmm, you look Asian, you'll probably react well to this particular drug." It might not be right in this particular person's case, but unless we have a family history that gives us better information, it might well be all we have to go on.

In some ideal future, we may have a Star Trek tricorder paired with a fully grokked human genome, and we'll immediately know everything that genomics can tell a medical professional about any person. That day will come, but it is not here yet, not by a long shot.

So where does all of this leave us? With a reminder that genetics is an exciting field that should tempt any student. Even though the human genome has been completed, there's a lot we still don't know, and indeed including much that may never be known. Too much remains hidden in our genes for the biological sciences to completely abandon socially-derived categories for human beings. Race, however, brings little to the table; especially in a globalized populace, a visual phenotyping is past the point of utility in determining genotype. Population and ancestry are far more useful than race, but they are not always evident or available. Given the lack of a Star Trek medical tricorder, the simple fact is that we don't have a solution yet. Biologists and geneticists must struggle on with inadequate tools.

Race, from a sociological perspective, still has relevance when we seek to help everyone achieve their potential. Although fraught with shortcomings, it still has an awkward place in some biological sciences. We can't ignore the fact that the very idea of race has had devastating and offensive consequences to our history; that's quite an accomplishment for something that provably does not exist. We find ourselves mired in a self-defeating bog of damned-if-you-do, damned-if-you-don't. The problem is not one with a tidy solution. But it is not a hopeless situation. With each passing day, the usefulness of race in any science diminishes, and then it will have no place at all. It will, ultimately, find itself in the landfill of discarded human follies where it so rightly belongs.

By Brian Dunning
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