The Invisible History of the Human Race (30 page)

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The Jefferson/Woodson story was painful because a family that had achieved so much in the face of adversity felt that they had been ejected from a larger group to which they proudly belonged and from a history that belonged to them. The Jefferson story had given family members great strength and motivation at significant moments in their lives.

The consequences for the lineages of Madison and Eston Hemings, both black and white, were different: For them the DNA provided a triumphant vindication of their family history. It was not an abstract vindication, either. As Williams pointed out the story of Madison and Eston’s paternity changed the lives of individuals within those families, and it provided the rest of the country with a newly accurate model of how some postrevolutionary families were shaped. The lineages of Madison and Eston Hemings had lost touch with each other, but when the Jefferson DNA results were published, Julia Jefferson Westerinen, a white woman and a descendant of Eston, and Shay Banks-Young, a black woman and a descendant of Madison, met for the first time. Since then, Thomas Jefferson’s white and black granddaughters have publicly spoken many times about the way that embracing each other and learning from each other has changed their lives.

It’s likely that as we become more adept at reading the stories of the past in the molecules of the present, this new knowledge will affect
whom
some people feel they belong to. When Foster analyzed the Jefferson Y, genetic genealogy was an infant science, and companies like the Sorenson Molecular Genealogy Foundation and Family Tree DNA were in their earliest stages of development. It took a private researcher like Foster, with his background in pathology, to devise the experiment, order the analyses, and interpret the results. Less than fifteen years later, anyone with a credit card can dip into his family’s invisible history via his own genome.

The power that these tests give us—to see with such clarity so far back into the history of humanity—is unprecedented. The additional opportunity to locate an individual’s personal history within that larger context was, up to the point where it became possible, completely unimaginable. Yet this new knowledge does not come without cost. Users risk discovering facts that for whatever reason they may not wish to know. The only way to truly block such risks is to halt the research or to legislatively restrict access to it. If someone could have stopped the Jefferson study before it changed history, it would have meant that on the one hand, the Woodsons would have been able to keep their legacy, but on the other, all the descendants of Madison and Eston Hemings would have continued to be disavowed.

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Despite its potential for great good, many critics have spoken forcefully about the negative impacts of reading history in DNA. The concerns are real, and much of the commentary reflects a sense of responsibility in the scientific community. Still, the collective response can give the impression of a great, looming threat.

In 2007 a group of scientists published a policy discussion about ancestry testing in
Science
, in which they stated, “Genetic ancestry testing . . . has serious consequences. Test-takers may reshape their personal identities and they may suffer emotional distress if the
results are unexpected or undesired.” The American Society of Human Genetics examined the topic with some optimism but much hand-wringing in 2010, noting that “the very concept of ancestry is subject to misunderstanding in both the
general and the scientific communities.” An earlier paper in the
British Medical Journal
stated, “Tracing genetic identity can lead to the resolution of uncertainty but can cause
more problems than it solves.” Some critics view the motives of anyone who wishes to look at his own genome as potentially suspect.

Writing about early-stage misinterpretations of genetic data, the biological anthropologist Jonathan Marks worried, “With genetic data, it seems, one could find entities that did not really exist, or impose cultural assumptions on the data and mistake them for patterns inherent in the data, yet still cloak oneself unimpeachably in the mantle of modern science.” In a caption to a racist depiction from 1842 of the different skull shapes of a Caucasian, an African, and a chimpanzee, he wrote, “As the authoritative voice on identity and descent, science’s track record is hardly blemish free”—a sentiment with which
few scientists would disagree.

Kim TallBear, an assistant professor of American Indian studies at Arizona State University, wrote that genomic scientific techniques, specifically those of the Genographic Project, have emerged out of the racial science dating back to the seventeenth century. The hope expressed by Genographic and genetic genealogy companies that this science was different—that it sought not to affirm racist categories but to demonstrate that they were cultural and unsupported by nature—was, to her mind, “naive at best.” TallBear also wrote that the claim that genetic proof of humanity’s African origins was “anti-racist” was complicated by the fact that it involved “portraying
Africa and Africans as primordial.”

The intent, of course, is to ward off the most venal use of biology, the specter hanging over all genetic research and all genealogy as well. Men like Francis Galton, Madison Grant, Heinrich Himmler, and Adolf Hitler have left in their wake a deep fear about the abuse of science, including the notion that merely considering the human genetic network will either make us all racist or justify our latent racism. I once spoke about the genetics of ancestry with a Holocaust historian who had hunted some of the last surviving Nazis in the 1990s. When I told him that little letters in our genetic code might testify to the ethnicity of our parents and grandparents, he said, “The Nazis would have loved this.” They would certainly have seized upon the idea, but in the end the full picture would have let them down just as badly as all the other dubious measures of race they tried to develop. Comparing the volumes of people’s skulls proved pointless, as did trying to formulate an objective measure of beauty. Likewise, the bits of DNA that genetic historians study do not indicate what a person will look like, think like, or live like. They are records only of ancestry; they tell us that groups once existed that, for whatever reason, lived together long enough that they ended up with genetic commonalities.

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Around the same time that the Jefferson research was taking place, another hugely ambitious genetic project was stalling spectacularly. In the early 1990s, Luigi Luca Cavalli-Sforza founded the Human Genome Diversity Project (HGDP), the goal of which was to rebuild the biological and language trees of humanity by sampling the DNA of tens of thousands of people from all over the globe. It would be hard to overstate the contribution that Cavalli-Sforza has made, not just to the science of population genetics but to the imaginations of generations of population geneticists and historians. His early projects in the 1960s were the first attempts to rebuild the history of the world through the distribution of traits found in blood. His popular book,
Genes, Peoples, and Languages
, first published in 2001, outlined his ambitious work, bringing together evidence from languages and genes to unearth the history of humans. The Human Genome Diversity Project would not only enrich history, argued Cavalli-Sforza, but would also have medical applications and, by demonstrating that there was no such thing as biological race, would be a tool against racism.

For all its apparent idealism, the project’s organizers did not pay enough attention to addressing the contexts in which the project’s requests for blood, and ultimately for knowledge, were made. It was one thing for middle-class westerners who have access to the educational and medical outcomes of the project to share their blood, and the information in it. But many indigenous groups of interest to the project were still fighting for basic human rights and health care. They struggled with extreme poverty, terrible health, and overrepresentation in the criminal justice system. Many had experienced exploitation and even medical experimentation at the hands of scientists.

In response, small, well-organized activist groups created many impediments to the progress of the project. They pointed out that it was unclear whether pharmaceutical companies would be able to access the DNA and not only use the information it contained to make enormous profits but even to patent people’s genes. They claimed that some indigenous groups were afraid that the scientific story of the world would be used to rewrite their own cosmologies. Their objections were connected to issues of genetic ownership too, such as the question of whether an individual had a right to share his own DNA with the project if other people in his community did not want to. Ultimately, the contradiction that millions of dollars were being invested in the HGDP but not in the people whose blood it would use became overwhelming. Among some indigenous groups it became known as the Vampire Project. (At the same time, many of the same political battles were being fought over genetic and other research conducted on ancient remains.)

A small group of cultural anthropologists accused Cavalli-Sforza and his colleagues of racism and hubris. Some even questioned the scientific merit of the project, suggesting that its questions about human history were obscure and asking whether the genetics of a single group would ever shed light on any history but its own. Years later in a United Nations address, Cavalli-Sforza said, “Ignorance can breed fear and hate, but I have discovered that it is most dangerous when mixed with the personal
political agenda of science haters.”

For obvious reasons, genetic research with subjects whose history is less troubled provokes less overt concern. Recall that the genomes of the people in the British genetics project were so overwhelmingly similar that as far as current medical genomics is concerned, they were effectively the same. Yet there were still identifiable differences that told a historical tale: The subjects’ ancestors had lived in different regions and they had left a mark in the genetics of their modern-day descendants. As far as we can currently tell, these differences were shaped by the same neutral evolutionary mechanisms that result in some groups having
differently shaped skulls.

What is perhaps most confusing about the criticism of this kind of genetic research is that its detractors often cite one of the most popular ideas of the human genome era: namely, that DNA reveals that race is a myth and that beneath the skin we are all fundamentally the same. But how can this be true when another consequence of the human genome era is that we can now have our genome analyzed and our racial history quantified? Does race exist in our genes or just in our heads?

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The modern notion that there is
no such thing as biological race and that we are more alike across populations than within them can be traced to 1972, when Richard Lewontin, an evolutionary biologist and geneticist at Harvard, conducted a landmark experiment that continues to shape how people think about the subject. Lewontin looked at seventeen places in the genome where a single letter might be different between people, and he showed that for each of these spots there were more differences
within
populations—or what we often think of as racial groups—than
between
them. The implication was that the largest differences that exist between people occur along all sorts of spectra, none of which is racial. As Lewontin wrote:

Human races and populations are remarkably similar to each other, with the largest part of human variation being accounted for by differences between individuals. Human racial classification is of no social value and is positively destructive of social and human relations. Since such racial classification is now seen to be of virtually no genetic or taxonomic significance either, no justification can be offered for its continuance.

These findings were generally taken to mean that the ways we differ from one another across racial or ethnic divides are far, far smaller than everything we have in common; that even though individuals from different parts of the world may look different from us, they are generally going to be more like us than not; and that there is no biology of race. The findings were also taken to mean that you cannot identify a person’s background from his DNA. The Human Genome Project announced that “
two random individuals from any one group are almost as different as any two random individuals from the entire world.”

However, if you look at even more bits of the genome,
the picture changes. For example, in 2007 a team led by D. J. Witherspoon, a researcher at the University of Utah, examined the same question. They confirmed that if you were comparing a few hundred bits between people across traditional racial divides, you would still find that many individuals may have more in common across the divide than within their own group. However, if you took people from different populations in different parts of the globe and you compared
thousands
of bits of DNA, the picture changed: Increasing the resolution by looking at more DNA shows that people will tend to have more in common with an individual from their own population
than from a distant one.

Witherspoon and his colleagues refined the approach even further and demonstrated that actually, when comparing populations that have been separated geographically for a long period of time, you need only a hundred bits of DNA to tell which person came from which population, which may make it seem as if race could be detected in DNA. Actually, the researchers did find something in this data, but it was
not
race.

There are many reasons for this, some of which have nothing to do with genes. The first reason they didn’t find race in the genome is because it was never there to be found;
race
is an imprecise and ultimately unhelpful notion in biology. Part of its power comes from the implication that the divisions it refers to are absolute and eternal, yet “race” is one of the shiftiest words in language. Sally Hemings’s mother had a white father and a black mother, and Hemings’s father was white (Hemings shared a father with Martha Wayles Jefferson, the president’s wife). Yet had Hemings been included in consecutive censuses since 1790, when then–Secretary of State Thomas Jefferson instituted the first American census, at first she would have been noted without name or race, and she later may have been classified at different times as “mulatto,” or “black,” or “white.” The collection of traits that are supposed to distinguish different races changes in different eras, depending on who has power and who doesn’t. Not only is race defined with a good deal of arbitrariness, but
who
gets to define it changes too. Sometimes a racial category is imposed on people, and sometimes it’s one that people choose for themselves. Race fuses cultural traits with physical traits, and it presumes either that what is cultural is determined by what is physical or that they always go hand in hand.