In 2003, scientists completed the Human Genome Project, making it finally possible to examine human ancestry with genetics. Scientists have since tackled topics such as human migrations out of Africaand aroundthe world. And it’s not just scientists who are excited about human genetics: widely affordable at-home ancestry test kits are now readily available from companies like 23andMe, Family Tree DNA, and Ancestry. For $99—around the price of a romantic dinner or a pair of Nikes—a customer can receive an analysis from 23andMe indicating that they are, for instance, 18.0% Native American, 65.1% European and 6.2% African.
The soaring popularity of ancestry testing bespeaks a widespread perception that we can use these tests to dissect, delineate, and define our ancestral composition. Indeed, social media is teeming with blog posts, and even livestream videos, from excited customers bursting to broadcast their test results and their reactions. Ancestry test kits are the new “it” item—and with their success is the tacit admission of our belief that our DNA can sort us into categories like the “five races:” African, European, Asian, Oceania, and Native American (Figure 1A).
New findings in genetics tear down old ideas about race
Estimating our ancestral composition down to 0.1% seem to suggest that there are exact, categorical divisions between human populations. But reality is far less simple. Compared to the general public’s enthusiasm for ancestry testing, the reaction from scientists has been considerably more lukewarm. Research indicates that the concept of “five races” does, to an extent, describe the way human populations are distributed among the continents—but the lines between races are much more blurred than ancestry testing companies would have us believe (Figure 1B).
A landmark 2002 study by Stanford scientists examined the question of human diversity by looking at the distribution across seven major geographical regions of 4,000 alleles. Alleles are the different “flavors” of a gene. For instance, all humans have the same genes that code for hair: the different alleles are why hair comes in all types of colors and textures.
In the Stanford study, over 92% of alleles were found in two or more regions, and almost half of the alleles studied were present in all seven major geographical regions. The observation that the vast majority of the alleles were shared over multiple regions, or even throughout the entire world, points to the fundamental similarity of all people around the world—an idea that has been supported by manyother studies (Figure 1B).
If separate racial or ethnic groups actually existed, we would expect to find “trademark” alleles and other genetic features that are characteristic of a single group but not present in any others. However, the 2002 Stanford study found that only 7.4% of over 4000 alleles were specific to one geographical region. Furthermore, even when region-specific alleles did appear, they only occurred in about 1% of the people from that region—hardly enough to be any kind of trademark. Thus, there is no evidence that the groups we commonly call “races” have distinct, unifying genetic identities. In fact, there is ample variation within races (Figure 1B).
The divisions between races are doubtlessly blurred, but does this necessarily mean that race is a myth—a mere social construct and biologically meaningless? As with other race-related questions, the answer is multi-dimensional and may well depend on whom you ask.
In the biological and social sciences, the consensus is clear: race is a social construct, not a biological attribute. Today, scientists prefer to use the term “ancestry” to describe human diversity (Figure 3). “Ancestry” reflects the fact that human variations do have a connection to the geographical origins of our ancestors—with enough information about a person’s DNA, scientists can make a reasonable guess about their ancestry. However, unlike the term “race,” it focuses on understanding how a person’s history unfolded, not how they fit into one category and not another. In a clinical setting, for instance, scientists would say that diseases such as sickle-cell anemia and cystic fibrosis are common in those of “sub-Saharan African” or “Northern European” descent, respectively, rather than in those who are “black” or “white”.
However, even if scientists agree that race is, at most, a social construct, any cursory search of the internet reveals that the broader public is not convinced of this. After all, if an Asian person looks so different from a European, how could they not be from distinct groups? Even if most scientists reject the concept of “race” as a biological concept, race exists, undeniably, as a social and political concept.
The popular classifications of race are based chiefly on skin color, with other relevant features including height, eyes, and hair. Though these physical differences may appear, on a superficial level, to be very dramatic, they are determined by only a minute portion of the genome: we as a species have been estimated to share 99.9% of our DNA with each other. The few differences that do exist reflect differences in environments and external factors, not core biology.
Importantly, the evolution of skin color occurred independently, and did not influence other traits such as mental abilities and behavior. In fact, science has yet to find evidence that there are genetic differences in intelligence between populations. Ultimately, while there certainly are some biological differences between different populations, these differences are few and superficial. The traits that we do share are far more profound
Science and genetics: Instruments of modern racism
Despite the scientific consensus that humanity is more alike than unlike, the long history of racism is a somber reminder that throughout human history, a mere 0.1% of variation has been sufficient justification for committing all manner of discriminations and atrocities. The advances in human genetics and the evidence of negligible differences between races might be expected to halt racist arguments. But, in fact, genetics has been used to further racist and ethnocentric arguments—as in the case of the alt-right, which promotes far-right ideologies, including white nationalism and anti-Semitism.
Those who disagree with alt-right ideologies may assume that the alt-right is merely spewing ignorant nonsense. This is certainly true for some of the alt-right. What is perhaps a more difficult truth is that many of the alt-right do, in fact, understand biology and genetics to an impressive extent, even if this understanding is flawed.
However, this claim ignores that while there is evidence for the effect of Neanderthal DNA on certain traits, there has been no evidence for its effect on intelligence. Furthermore, scientific research indicates that the Neanderthals were not necessarily more intelligent simply because they had larger skulls. Unsurprisingly, the alt-right tends cherry-pick the ideas that align with their preconceived notions of racial hierarchies, ignoring the broader context of the field of human genetics.
Fighting racism with understanding
Just as the alt-right is no longer an easily dismissed fringe group, their arguments have some factual basis, and cannot be swept aside as the babbling of the scientific illiterate. The alt-right is not clumsy in their use of science and genetics in their battle for their “ideals.” Those who oppose the alt-right, and other racist entities, must arm themselves with the same weapons: education, namely scientific and genetic literacy.
Mounting scientific evidence has shown that humans are fundamentally more similar than different from each other. Nonetheless, racism has persisted. Scientific findings are often ignored, or otherwise actively misinterpreted and misused to further racist agendas of extreme political groups. Opponents of these forces must, through their own education and awareness, combat these misleading interpretations and representations of scientific findings.
Today, the question of “race” is no longer merely a political and social issue: as science has rapidly advanced, it has become irrevocably intertwined. The genome contains powerful insights about our biology that could unite us as a species, but which could also be dangerous and divisive if used without understanding. As we look forward to 2017 and onwards, it becomes ever more important to understand what our DNA says about what it means to be human.
Vivian Chou is a Ph.D. candidate in the Biological and Biomedical Sciences program at Harvard Medical School.