RACE DNA IF RACE IS A SOCIAL CONSTRUCT, WHAT’S UP WITH DNA ANCESTRY TESTING? BY JOSEPH L. GRAVES ILLUSTRATION BY KEN ORVIDAS THE CONCEPT OF RACE is the elephant hold positive views of the police, only 52 make it sound like we’re examining the in the collective American living room. percent of African-American individu- elephant while blindfolded. Some of us It a!ects how we think about virtually als and 51 percent of Mexican-American describe the trunk, while others the tail every aspect of our society and cul- individuals share that view. In addition, and still others the feet. Our descrip- ture—and yet we struggle to talk about when asked the question of whether the tions and definitions are di!erent, and or even define it. police use lethal force only when neces- without understanding how they fit Numerous studies demonstrate sary, 59 percent, 16 percent and 23 per- together, we cannot ascertain a com- that members of socially defined racial cent of European-American, African- plete picture of the elephant. groups in the United States experi- American and Mexican-American indi- To speak meaningfully about race, ence the realities of life di!erently. For viduals respectively responded in the we need to truly understand how dif- example, a recent public opinion sur- a"rmative. ferent people perceive and define it and vey showed that while 80 percent of Often, when we try to describe the how these definitions fit together. This European-American (white) individuals elephant in the room, our attempts includes understanding socially defined !"!TEACHING TOLERANCE SUMMER !"#$%!" race, biological race, human variation gene flow among its major population wherever malaria is found, including and ancestry. Unfortunately, most centers (or regional clusters of inhabi- West Africa, the Arabian Peninsula, Americans do not, with the result that tants). Indeed, all modern humans liv- the Mediterranean Basin and in India. many racist beliefs are passed along ing today are descended from people It is not found among Kenyans whose as scientific fact. Have you ever heard who once lived in East Africa. (The old- ancestry is from high-altitude regions the stereotype “African Americans are est modern human fossils come from of that country. Therefore the sickle lazy”? Someone who understood how Omo Kibish in Ethiopia.) Humans did cell gene can’t be used to define races. human behavioral variation relates to not begin to populate the rest of the Another relevant example is skin socially defined race would know this world until about 60,000 years ago. color. Skin color variation is associ- statement is not logically possible—and Some of the first recorded civilizations ated with solar intensity, and thus all yet it has been used for centuries as one were located in Ethiopia (prior to 3,000 populations with tropical ancestry have of a number of scientifically impossi- B.C.E.) and then moved up the Blue Nile darker skin than those whose recent ble justifications for the subjugation to modern-day Egypt. Thus many of the ancestry is from the temperate and arc- of African-American individuals. biological traits not found in sub-Saha- tic zones. Solomon Islanders, for exam- ran Africans are relatively new; fair skin ple, have physical traits very similar to Taking O! the Blindfolds and the blue-eye allele are—at most— sub-Saharan Africans, yet these Pacific The majority of Americans still operate 6,000 years old. Finally this also means Islanders are much further apart on on the assumption that there are legiti- that when most people think of biolog- overall gene frequency (the percentage mate biological races within the human ical ancestry, they are really envision- of genes of a given type) from sub-Sa- species, and that these racial categories ing recent ancestry relative to our spe- haran Africans than from Europeans. align with physical features—in other cies’ existence (within the last 50,000 A less visible evolutionary trait is the words, the way that race is socially years or so). ability to tolerate milk beyond the defined in the United States. To debunk This is where our understanding age of weaning, which evolved both in this misconception, it is important to often gets fouled up. How is it possible Europeans and in some Africans (Masai understand two often-conflated defi- that geographically based genetic and tribe) due to the domestication of cat- nitions of race. physical variation can tell you some- tle. It stands to follow that if we attempt k BIOLOGICAL RACE has been thing about an individual’s recent bio- to infer relatedness between human defined by combinations of physical logical ancestry, and yet that variation groups based only on physical traits features, geographic ancestry, frequen- is not useful in identifying an individ- like dark skin and milk tolerance, we cies of genes (alleles) and evolutionary ual’s biological race? Isn’t it true that consistently incorrectly assign groups lineages. Biological races exist within Norwegians have fair complexions and of people together. some species. This is why we know they Nigerians are dark? Physical factors fail to correctly clus- do not exist within our species, modern It is true that all modern human ter humans and thus cannot be used to humans. populations have genetic di!erences assign people to racial groups—a fact k SOCIALLY DEFINED RACE has been that reflect adaptation to the environ- scientists have known since the 1940s! defined by an arbitrarily organized ments their “recent” ancestors inhab- Yet today, most Americans still combination of physical traits, geo- ited. There are also genetic changes utilize physical features to judge the graphic ancestry, language, religion that resulted from simple chance racial alignment of individuals. This and a variety of other cultural features. events. Have you ever heard the term mistake is understandable in the con- Social definitions of race di!er depend- “genetic drift”? This refers to chance text of American history, since physi- ing on context and always operate in the events that alter gene frequencies in cal features were a reliable indicator service of social-dominance hierarchies. populations. This happened when of ancestry for much of the nation’s The modern consensus of evolu- human groups migrated out of Africa history. Western Europeans (mainly tionary biologists is that our species at different times and in different from England) founded this coun- does not have enough genetic variabil- directions. Members of a given group try. They invaded the territory of the ity among its populations to justify carried a unique subset of all human American Indians (whose recent bio- either the identification of geograph- genetic variation with them. For all logical descent was from Central ically based races or of evolutionarily these reasons, there is no single phys- and Northeast Asia), and then cap- distinct lineages. This is because we are ical trait or gene that can be used to tured, transported and enslaved peo- a relatively young species (150,000– unambiguously assign people to racial ple from West and Central Africa. 200,000 years old) that has always groups. Here’s an example: The sickle This meant that the original inhabi- maintained significant amounts of cell allele is found in high frequency tants of our country were drawn from !"!TEACHING TOLERANCE geographically disparate portions of ancestors have been on this continent π LEARN MORE ∏ the human genetic spectrum. However, for 13 generations. This also means you soon after these populations were contain—from that time to now—the History reveals many brought together they began to amal- genetic material from as many as 8,192 instances in which gamate (sometimes willingly, some- individuals! And that estimate doesn’t times by force). Soon physical appear- even begin to touch the number of institutional racism ance was no longer a reliable determi- ancestors who came before your genes influenced science and nate of ancestry. arrived in North America. Although it is not possible to deter- vice versa. Learn how one Genetics of Race and Ancestry mine someone’s socially defined race physician’s theories —which We’ve determined that “biological by examining their DNA, it is possible races” in the human species do not to estimate the continental origin of we now know to be deeply exist. They cannot be determined by different segments of an individual’s flawed—were used to either physical or genetic measures; DNA. Remember that all of us have deep what we think of as “races” are socially ancestry in East Africa; the proportion justify chattel slavery. assigned sets of characteristics that of our variable DNA that falls into that Visit our sidebar at change depending on context. This category is about 85 percent. This means does not mean that there is not geo- that about 15 percent of our “recent” tolerance.org/ graphically based genetic variation DNA could potentially be differenti- samuel-morton-wrong found in our species. It simply means ated by continent or region within a con- that this variation is not su!cient to tinent. No single genetic marker is going describe biological races within the to be a reliable estimate of ancestry, so species. How then is the concept of statistical methods, such as maximum ancestry different from that of race? likelihood, are used to make estimates Understanding the di"erence requires of a person’s ancestry. understanding these two definitions: Ironically, ancestry studies have k BIOLOGICAL/GENETIC ANCESTRY revealed a great deal about the history is the proportion of recent ancestry displayed in an individual via genetic material inherited from one’s ancestral geographic origins. k SOCIAL/CULTURAL ANCES! TRY refers to the origin of atti- tudes, beliefs and behaviors dis- played by an individual.