“I Am a Zulu”
A village in Mozambique.
“I am a Zulu,” famously declared the best-known African American woman alive today, Oprah Winfrey. Being Oprah, her words were flashed around the world. Literally, of course, she is not a Zulu but an extremely gifted television host, author, businesswoman, philanthropist, and campaigner. But her choice of words was very telling: She used “I am,” not “One of my ancestors was.” Oprah’s declaration of her African genetic roots followed a genetic test of her mitochondrial DNA, and though it was not the first time an African American had made this connection, it was certainly the most celebrated.
Tracing their African roots through mitochondrial DNA has been enormously helpful to many African Americans. While European genealogists concentrate on their patrilineal genetic roots through the Y chromosome, often flowing side by side with a surname, the obliteration of genealogically meaningful names for African slaves means this avenue is closed off. There are other reasons, too, why the Y chromosome is perhaps the worst DNA for African Americans to use to connect with their African roots. Fortunately the quest for matrilineal ancestors is helped by the fact that more than 97 percent of African Americans have inherited an African mitochondrial lineage from their mothers, their grandmothers, and back through the generations to the slave ancestor who crossed the Atlantic. Of course African Americans usually have many more African ancestors than this, but the precision of mitochondrial DNA and the special place that maternal ancestors hold in all our memories make this small piece of DNA both the most reliable and the most precious.
As I saw at firsthand with Jendayi Serwah, finding a match between her and a Kenyan Kikuyu was a transforming experience for both of us. The match was an exact one in that the dozen mutations that defined her sequence were exactly the same as the anonymous Kikuyu. Anonymous because, like all academic research projects, the volunteers are protected by confidentiality clauses in the ethical approval that all such studies must obtain before they begin. These anonymous studies have been essential for revealing the indigenous patterns of African mitochondrial DNA, as we have seen, although they will never directly identify an individual as a relative. Nonetheless, close or exact matches between African Americans and indigenous research samples can give clues to an ancestral homeland in Africa. But it is not completely straightforward, for reasons that we have touched on in the previous section. For example, although Jendayi is an exact match with a Kenyan Kikuyu, that does not necessarily mean that the woman from whom they both inherited their mitochondrial DNA was herself a Kikuyu. They are both in the clan of Leisha (L2A). Leisha lived about fifty-five thousand years ago, well before the subsequent migrations within Africa that scattered her descendants far and wide across the continent. The precise sequence match means that their common ancestor lived far more recently than Leisha herself and probably within the last few thousand years. That is an average figure based on the mitochondrial DNA mutation rate, but the range of possibilities is very wide. We also know that the clan of Leisha is found not only in West Africa, but also in southeast Africa as a result of the Bantu expansions, which is what probably carried the lineage from West Africa to Kenya. We know from the history of slavery that it is far more likely that Jendayi’s ancestor was taken from West Africa than from Kenya, but we cannot be absolutely sure. But it is so much better than nothing.
Comparing the mitochondrial DNA of African Americans with their indigenous African cousins is also very revealing about the geography of slavery. At first the absence of matches was perplexing. Take the clan of Lalamika (L1C). Many African Americans are members of this clan, but among indigenous Africans whose DNA has been tested it is comparatively rare. For example, among all the indigenous Africans sampled until 2006, there were only nine. Seven were from Mozambique in southeastern Africa, another from the Cameroon mainland, and the last from the island of São Tomé a hundred miles offshore. But, among a much smaller sample of African Americans, there were sixteen who belonged to this branch of the clan. Here I am using “African American” in its widest sense, in that this number included two Mexicans, four African Brazilians, and three “White” Brazilians.
At the opposite extreme, in the sister clan of Latasha (L1D) there are sixty-one Africans among the indigenous volunteers and not, so far, any African Americans at all. This mismatch is also explained by the geography of slavery. The indigenous African representatives of the Latasha clan are made up of forty San Bushmen from the Botswana Kalahari, twenty Bantu speakers from Malawi and Mozambique, and one solitary member of the Turkana tribe from northern Kenya. There are none at all among the almost five hundred African Americans included in this study. The reason is simply that slaves were not taken from Botswana’s Kalahari Desert or from Malawi, both of which are far from the coast. They were, however, taken from Mozambique, so I think it is only a matter of time before we do see an African American in the clan of Latasha.
These two very different portraits are partially explained by the mechanics of the slave trade. While most ships left Africa bound for the Americas from the west coast, this was not always the original source of their human cargo. The Portuguese colony of Mozambique, facing the Indian Ocean, exported over a million slaves, and African Americans in the clan of Lalamika probably started their journey from there, via the offshore island of Zanzibar that had been an active Arab slave port for centuries. But before they crossed the Atlantic, slaves from Mozambique were often “stored” on the Portuguese island of São Tomé, awaiting shipment. Most likely the ancestors of the two clan members from São Tomé and Cameroon were also from Mozambique but somehow managed to avoid being taken across the Atlantic.
The relatively few absolutely exact genetic matches between African American and indigenous Africans in this example is partially a reflection of the extreme intrinsic diversity of African mitochondrial DNA that has had so very long to accumulate its huge range of mutations. Outside the family, almost everybody else is different. But it is also due to one other important but often-neglected reason. Put simply, if a region has not been sampled, there will be no matches within it. The research results we have been examining are distilled from about twenty different projects. By the nature of academic research, these projects are limited in scope. They are constrained by the amount of funding available, by the opportunities and permissions to study particular tribes or particular regions and by the time pressure to publish the conclusions. Fortunately the results from these separate projects can be combined because the mDNA sequences are all directly comparable. But there are always regions where no research has been done. Either it is too dangerous, or permissions are hard to get, or stretched funding agencies are not eager to pay for yet another project that looks awfully similar to the last one—there are a host of reasons. Angola, for example, was not widely sampled until recently due to the long-running civil war from 1975 to 2002. After the war was over and genetics results were published, mDNA matches between indigenous Angolans and African Americans began to appear.
The strength of feeling connecting African Americans to their African cousins now has its ambassador, its go-between, in mitochondrial DNA, and thousands of African Americans have drawn great strength from the genetic testimony it carries. Though this phenomenon shares some of the ingredients of the deep-rooted desire of many Europeans to discover which of the “Seven Daughters of Eve” is their ancestral clan mother, it has the added dimension of revealing, if only dimly, a past that has been completely and deliberately hidden. It bolsters the feeling of identity that many African Americans feel for their ancestral continent. While there were hints of this in the early days, as my experience with Jendayi had shown me, it was only when public access to testing became widely available that the full extent was revealed.
Public participation by African Americans began in earnest in the United States on February 21, 2003, when Dr. Rick Kittles and his business associate, Gina Paige, set up African Ancestry. Rick is a physician and geneticist, now at the University of Illinois, and as well as his work on the genetics of prostate cancer he has been instrumental in developing ways of estimating the proportion of African DNA in individual genomes, in ways that we will come to later. He told me when I visited him in Chicago that he remembers the start date of African Ancestry very precisely, as he and Paige had to rush to launch the company during Black History Week. Being an African American himself, like Paige, he realized the potential in linking individuals to Africa using their DNA, and appreciated the intrinsic qualities of mitochondrial DNA to do this. But as we have seen already, the potential is severely limited without large numbers of indigenous African DNA sequences for comparison. In 2002 there were not that many available, so he set about collecting his own. This is where the conflict between the academic and commercial worlds began, and it is one that I am familiar with myself.
The natural inclination of academics is to make results freely available through publication in scientific journals. Indeed it is an obligation for anyone employed by a university. Academic research was the only source of mitochondrial sequences until a decade ago, and without it there would have been nothing on which to base any commercial service. And without that there would have been no widespread public access, and no one outside a university research department would have been able to have his or her DNA analyzed on request. I know some of my university colleagues shrink from the idea of commercialization, but I believe they are mistaken. It seems to me that academic research should do the trailblazing, but after a while, when the rules are understood and the field settles down, it doesn’t seem appropriate that public money or research charities should pay for all the implementation. Researchers should get on with something new, or explore avenues that are unsuitable for private funding.
Kittles and I met in his office at the University of Chicago, and we both soon realized that we had shared similar experiences in opening the academic closet and letting people see inside—“taking the American Journal of Human Genetics to the street,” as he put it succinctly. Although Kittle’s main career has been centered on cancer genetics, he started out doing a graduate dissertation in biological anthropology. Being African American he naturally wanted to focus on Africa, but there were just no samples. There may be many shortcuts in research, but there is no getting away from the fact that to look into African genetics you need African DNA. However, there was an ongoing research collaboration in the department with Finnish scientists who were looking into the possible genetic basis for their country’s distressingly high rates of alcoholism. And for that reason the lab freezers were full of Finnish DNA. You couldn’t get much farther away from Africa, on the equator, than Finland on the Arctic Circle, but Kittles relished the thought of using the then newly discovered tools of mitochondrial and Y-chromosome DNA, albeit in much cruder ways than nowadays. In a nutshell he found that roughly half of Finnish Y chromosomes had come from Asia, while the mitochondrial component was determinedly European. As is often the case, the Y chromosomes were much more limited in their genetic diversity, a sure sign that a few men had more than their fair share of children. It is a picture I recognized only too well from Celtic Britain.
After finishing his thesis, Kittles was able to focus on Africa when he got his first position at Howard University in Washington, D.C. Howard was founded in 1867, just after the end of the Civil War, with the express intention of admitting African Americans, a guiding principle it maintains to this day. The medical school, which Kittles joined, has a reputation for training doctors from Africa, so, as well as a good complement of African Americans, there was a constant flow of students back and forth. That was the means by which Kittles built up his collection of indigenous African samples. He soon found a match for his own mitochondrial DNA, which is in the clan of Lingaire (L2C), among the Hausa of northern Nigeria. His Y chromosome on the other hand is European. The natural assumption for an African American is that one of his enslaved maternal ancestors was impregnated by a white man, possibly her owner—an extreme version of proprietorial rather than aristocratic diffusion, in other words.
However, I was fascinated to discover that there could be another explanation. Kittles told me that along the coasts of West Africa he had found that between 5 and 10 percent of fishermen also had a European Y chromosome. Coastal fishermen often have a different gene pool than do their inland neighbors. This was picked up a long time ago around the coast of Scotland when the blood-group composition of fishing communities was found to be quite different from that of the inland population nearby, and much more similar to that of fishermen and -women from other parts of coastal Scotland. The explanation of the European Y chromosomes among West African fishing communities is more about the flow of genes around the coasts of the Atlantic. The same flow has brought African DNA to the islands off the west coast of Scotland, as I discovered in my British research. It means, of course, that some African Americans may have gotten their European Y chromosomes from fishermen on the Atlantic coast of Africa, and not from white men in America. Some, but not all.
Kittles is one of the many African Americans who have visited the homeland of their ancestors in so far as it can be identified through DNA. A few years ago he traveled to the Jos plateau in north-central Nigeria to visit the Hausa, the African tribe with the closest mitochondrial DNA matches to his own. It was both a frightening and a reassuring experience, he told me—frightening because the Jos plateau, in common with much of northern Nigeria, is embroiled in a war between Christians and Muslims. The roads were terrible, there were no lights, and no one dared to drive at night. There were potholes everywhere and larger craters with cars and even buses sticking out of them. The most profoundly disturbing images, however, were the unburied human bodies that littered the sides of the roads. Approaching a Hausa township one day, the car was pulled over and the driver gestured that he had better get out. Kittles was immediately surrounded by a hostile crowd, dressed in the long robes of Islam. However, what could have been a very dangerous moment was suddenly transformed. Among the men who surrounded the car was someone he recognized. Standing there was a man who was the spitting image of his uncle Clifford, his mother’s brother. They looked almost exactly alike. It wasn’t his uncle, but the mutual sense of recognition brought about by their shared ancestry immediately defused the tension. Rick suddenly felt the warm sense of kinship. It was, as he told me, “a very weird moment”. Not really scientific at all.
Not being an African American, I don’t expect I shall ever be able truly to understand the strong feelings of not knowing my roots and the void that it leaves: knowing you come from Africa, but not which part. Claiming in your mind the whole of Africa until you get a call from the messenger in your cells and can return to your home and begin to shape your true identity. That being said, many African Americans realize only after they visit Africa that they have more in common with America than Africa and that they can never truly go “home” again.
But things don’t always work out as expected. Around a third of Kittles’s African American customers turn out to carry European Y chromosomes. How do these men take the news? Not always well. About half of them are angry and frustrated and call up the company. They get mad and they want their money back. They know the general history of their race, but they look black and they certainly feel black. “How can I have a European Y chromosome?” they ask. “There must be some mistake.” So the tests get repeated, and the answers come back the same. By then a lot of them have had time to think about it and have quieted down. Maybe they have asked their grandmother on their father’s side, and she may have said there was talk of a white ancestor in the family a long time ago. Always ask a woman about these things, I have learned. Women always know more than the men.
When African Ancestry started out, it wasn’t easy to know how to respond to the intensity of the reaction. Had Kittles anticipated it, he told me that he would have engaged a psychologist from the start. He has one now, who helps to manage the responses to unexpected or unwelcome news. With the experience of the years, Kittles has come to realize that a client’s response to a DNA test is a mixture of two things: motivation and expectation. Many of his clients have well-established oral histories, and when the genetics runs counter to these expectations, it gets hard.
I feel a lot of empathy with Rick Kittles because at Oxford Ancestors we occasionally come across dissatisfied customers who just refuse to believe the implications of their DNA results. One of the services the company offers is to give our estimate as to whether a customers’s patrilineal ancestor was a Viking or a Saxon or a Celt. The “Tribes of Britain” test, as it’s called, is based on a large genetic survey of Britain and Ireland involving thousands of volunteers. Just recently I spoke with a man who was so sure his ancestor was Celtic that, when the “Tribes of Britain” tests showed his ancestor was probably a Viking, he called us. “I am certainly not a Viking,” he said before demanding his money back. (I secretly suspect that many of our clients would prefer to be descended from Vikings, but he clearly wasn’t one of them.) Usually the office staff can smooth things over, but he was so insistent that I called him myself. “I want my money back,” he said immediately. When I asked why, he replied, “Well, you said I was a Viking.” “Yes,” I replied. “But I’m not a Viking, I’m a Celt.” Thinking that sometimes you just can’t win, I asked, “How do you know?” “Because I am dark haired and short.” At that point I gave up, realizing once again that DNA always struggles to reverse the deepest of psychological perceptions or identity associations.