Digging for DNA

Archaeology, Genetics, & the Trans-Atlantic Slave Trade


Marcela Sandoval gave me a wry grin, then covered her face with a mask. Next, a covering for her hair, goggles, booties over her shoes, and a crisp, white suit that crinkled when she moved. Finally, a pair of turgid purple latex gloves snapped into place. She put her hands on her hips and impatiently motioned for me to get on with it. I awkwardly pulled on my own clean suit and followed her into the laboratory, where a faint glow outlined test tubes and complex machines.

Here, in this quiet room, was the beginning of a complex, captivating story about genetics, ethnicity, and the archaeological past.

The pristine “clean room” in the middle of genteel, bicycle-friendly Copenhagen was far removed from the dirty excavation trenches that usually characterize archaeological research. I always felt most at home with a trowel in hand, under the wide-open sky. Wearing a filthy t-shirt, even dirtier pants, muddy boots, and a scarf tied around my head, I would excavate broken pottery, mudbrick architecture, and sometimes human remains. Discoveries were carefully recorded, photographed, then fit into a larger picture of the past. At some sites I would be lucky to shower a few times a week. This was the way I and most people understand archaeology, as digging up ancient treasures in far-off places. Yet discoveries in the clean environment of laboratories in Europe have been radically changing how archaeologists and historians understand the past.

Clean suits at the Centre for GeoGenetics at the University of Copenhagen

I was in one such lab at the Centre for GeoGenetics at the University of Copenhagen, where academic researchers like Marcela have been making stunning discoveries. The Centre is housed in the Natural History Museum, a grand old brick building full of fluorescent ores and toothy dinosaur skulls. I first visited the Centre in mid-January, and the frozen sculpture gardens made the museum look bleak and forbidding — the perfect place to re-animate the dead. The grand entrance hall was full of marble and richly burnished wood, but I went through an unremarkable side-door to the tidy, Danish Modern decor of the museum’s administration office. The bright labs on the upper floors of the building also belied the dark exterior, and had views of the red-tiled roofs and copper domes of Copenhagen.

Under the leadership of Professor Eske Willerslev, the Centre for GeoGenetics, along with a few other research labs specializing in ancient genomic sequencing, have produced a flurry of publications that are rapidly changing what we understand about the past. The study of ancient DNA, or aDNA, has captured imaginations since the movie Jurassic Park.

This idea, of resurrecting mammoths, the dodo and other extinct animals from fragments of preserved DNA, is rapidly moving from science fiction into serious academic discussions.

Recent advances in DNA sequencing and better methods to capture and enrich samples have resulted in the recovery and extraction of aDNA from samples that were not previously possible. Not content to extract DNA from plants and animals, geneticists have been working with archaeologists to use these new techniques on the remains of our ancestors.

La Braña 1, Credit: Spanish National Research Council

In March, scientists from the Centre for GeoGenetics analyzed the DNA from the tooth of a 7,000 year old Mesolithic hunter-gatherer from Spain, finding his lineage stretched all the way from Siberia. Researchers named him La Braña 1. From analyzing his genotype — the genetic make-up of an individual — researchers could tell that he was lactose intolerant, would have struggled with the starches in the diet of the later Neolithic farmers, and had dark skin and blue eyes. Facial reconstructions emphasize those piercing blue eyes, staring out from beneath thick eyebrows and shaggy hair.

Recovering this amount of detail about an individual is a breathtaking, intimate window into our distant past.

This Mesolithic hunter-gather joins a growing crowd of individuals emerging from this new research on archaeological remains. In 2011, the Centre identified the unique ancestral journey of Aboriginal Australians in a genome sequenced from a lock of hair. The hair had been donated to a British anthropologist in the early 20th century and sat in a museum for nearly a century. Samples taken from the oldest burial found in North America — the 12,600 year old skeleton of a child in Montana — definitively linked the migration of the Clovis people to Asia.

I always read the press releases about this research with glee. The idea of our ancestors lurching forward to lean out from the past is arresting, and inevitably someone finds a photo of a movie star that remarkably resembles the ancient person. Our Mesolithic hunter-gatherer was favorably compared to Gerard Butler, best known for his role as the muscular, shouting Spartan King Leonidas in the movie 300. Still, I wasn’t sure how the muddy holes in the ground that I had been digging could be connected to producing a would-be prehistoric celebrity.

While archaeologists have been using information from population genetics since the 1980s, it is the recent improvements in the extraction and analysis of aDNA that have radically improved the fidelity of these studies. The field of population genetics, a sub-specialty of evolutionary biology that examines the changing genetics of populations due to evolutionary processes, has significantly advanced over a short amount of time. After the development of the technique of amplification, that is, making many copies of small pieces of degraded DNA, researchers have mined the collections of museums for traces of aDNA, resulting in a steady stream of these headline-making publications.

But for her PhD research, Marcela Sandoval was doing something different. She was not looking at museum samples or mesolithic hunter-gathers. Marcela was studying DNA from much more recent ancestors: Africans enslaved and transported during the Trans-Atlantic Slave Trade.

Cape Coast Castle, Ghana. Used for the Transatlantic Slave Trade.

The lab was still — the only other white-shrouded scientist in the room was in a far corner, huddled over a series of vials. From behind her mask, Marcela explained how the DNA was processed. First she would pulverize the sample of organic material, usually bone. Then the powder was “digested,” meaning that the structures of the bones were broken up to extract the strands of DNA. In most of the samples taken from old bones, the DNA was fragmented, much like any other archaeological remains. To be able to identify the DNA fragments, the sample needs to undergo amplification, and then is chemically prepared for sequencing. One of the problems with aDNA research is that the sample could contain other genetic material; samples collected from the remains of mammoths and neanderthals included DNA from bacteria, dogs, and modern humans.

Each of the researchers dealing with aDNA have to get their own genotype created so they can identify contamination.

After identifying and isolating the endogenous DNA — the DNA that comes from the ancient human and not other contaminants — the DNA is mapped to the human genome and analyzed for sequences that may identify specific traits such as eye color, or geographic origins. The specific techniques for each of these steps is quickly improving, and lab methodologies can change completely within the space of six months.

Only a few years ago, ancient DNA researchers had to content themselves with analyzing very short stretches of DNA, only a few base pairs (bp) long; today they study entire genomes. The recent, rapid pace of development in population genetics has not yet made an impression in mainstream archaeological research. In 2014, at the two biggest archaeological conferences in the world, the Society for American Archaeology and the European Association of Archaeologists, each with thousands of participants, a scant two papers and a single session mentioned genomic research. A clue to this discrepancy may be in the type of samples required to conduct this research: human remains.

As she was explaining the procedures in the lab, Marcela opened a large freezer full of opaque plastic bags and boxes. She pulled out a small bag and we peered inside.

The samples she used to extract aDNA were at the bottom and would be recognizable to anyone — human teeth.

These teeth were gathered after the excavation of burials as part of archaeological field work on the remote island of Saint Helena in the South Atlantic. When the United Kingdom outlawed slavery, the Royal Navy captured slaving ships and would land the formerly enslaved Africans on Saint Helena, one of the three court locations that could adjudicate cases against the slavers.

After enduring the wretched conditions on a slave ship, many of the refugees on Saint Helena were in bad physical shape. Over 8,000 of the liberated Africans died and were subsequently buried on the island. Enslaved, then freed, only to die on a remote island, the burial of these Africans represents the stark horror and deep, lingering violence of the Trans-Atlantic Slave Trade. In their mid-Atlantic death, they also represent a unique archaeological population — Africans who were enslaved, but did not survive to reach their destination in the Americas. By conducting this research, Marcela is able to shed new light onto a problem that has long eluded historians: who was enslaved during the Trans-Atlantic Slave Trade, how diverse were these people and where did they originate?

EUROTAST fellow Cesar Fortes Lima talking about his research to colleagues in Senegal.

Marcela’s study of the aDNA from the remains of Africans buried on Saint Helena is one of thirteen PhD research projects that form EUROTAST, a collaborative, interdisciplinary network that explores the history, archaeology, and new genetics of the Trans-Atlantic Slave Trade. EUROTAST is funded by the European Union Marie Skłodowska-Curie actions. Named for the two-time Nobel Prize winning scientist who is famous for her work on radioactivity, Marie Curie initiatives are designed to promote research and innovation through mobility across national borders: Marcela is originally from Mexico, and there are fellows from Germany, Iceland, New Zealand, Slovakia, United States, Canada, Brazil, India, United Kingdom, and the Caribbean island of Saint Lucia. The PhD fellows attend universities outside of their own country, promoting the cross-pollination of ideas and research contacts, ultimately creating an international research community. Together, these researchers are examining how slavery fundamentally shaped the cultural and biological experiences of people of African descent around the world.

Hannes Schroeder and Tom Gilbert, EUROTAST project coordinators

EUROTAST came together under the guidance of Tom Gilbert and Hannes Schroeder at the University of Copenhagen. I met them both in January, after I was hired as a research postdoc for the network. At the time, two years of the four-year EUROTAST project had passed. Used to explaining his complicated, nuanced research to non-specialists, the startlingly young Hannes is relaxed and informal, leaning back to clasp his hands behind his head as he speaks. His accent reveals a peripatetic career, sometimes German, English, then a bit Danish — Hannes was born in the former East Germany, received an archaeology degree from University College London, then a D.Phil from Oxford. When I ask about his vision for EUROTAST, Hannes becomes animated, leaning forward in his chair. He excitedly explains the purpose of EUROTAST:

“the history of the Trans-Atlantic Slave Trade has been largely the domain of historians; but we brought in archaeologists, anthropologists, geochemists and geneticists to uncover new facts about the Trans-Atlantic Slave Trade and its legacies today.”

One of the big questions the EUROTAST researchers are trying to address relates to the origins of the millions of Africans who were transported to the Americas as slaves. The geographic and ethnic origins of enslaved Africans is a deeply important, personal question for many people from the African diaspora. The records and histories written by the slavers homogenized enslaved Africans into a single group of other people, people without a history or family, people that subsequently could be safely considered chattel. Some African Americans have been resisting this homogenization by using oral histories and genealogical information to trace their roots back to regions and ethnic groups in Africa, with varied success. The advent of genetic ancestry testing has offered a new line of evidence, one that appears to provide direct links to African ancestors. Yet the link between the enslaved Africans and the African diaspora remains diffuse, disconnected from other supporting evidence in the historical or archaeological record.

To address these questions, the EUROTAST fellows came from a variety of backgrounds, broadening from the focus on aDNA to incorporate methods from anthropological ethnographic studies, computer science, history and scientific methods in archaeology such as protein extraction and isotopic analyses to shed new light on the Trans-Atlantic Slave Trade.

While scientific research can be extremely competitive between labs, through the EUROTAST network the fellows are able to share data sets, methodologies, and collaborate on writing research papers, sometimes using samples from the same individual for different analyses.

This approach can both mitigate the loss caused by these destructive methods and lend incredible detail to the final results. This level of attention to the archaeological remains of a single individual would not normally be possible, as each research institution can be incredibly specialized. EUROTAST brings together the resources of a network of researchers at large institutions who can use a wide range of methods to collectively study the Trans-Atlantic Slave Trade.

Erna Johannesdottir, making a cast of a tooth at the University of Bristol.

I met Erna Johannesdottir and Judy Watson at the same time, over a beer near their home institution, the University of Bristol. We had just finished a day-long meeting to discuss research on the burials from Saint Helena, and Marcela was there too. Earlier, the fellows had presented their progress on their research and they all looked relieved but slightly wilted. Originally from Iceland, Erna examines teeth from the same burials on Saint Helena that Marcela uses for aDNA sampling, but in a very different way. Marcela uses the teeth from the back of the mouth, the premolars, to extract aDNA. Erna takes casts of incisors, the front teeth, through a non-destructive process, leaving the originals on Saint Helena. These teeth exhibit incised marks that might be linked to different ethnic groups in Africa. With ethnographic research, Erna can approach the question of ethnic origins through body modification, evident in the preserved teeth from the burials.

Judy Watson is a fellow American and we chatted about the differences between research in the UK and the USA, and how hard it was to be far away from home. Judy also uses teeth from the Saint Helena burials for isotopic analyses. Performing isotopic analyses on teeth involves comparing the number of heavier atoms of a given element to the number of lighter atoms of the same element in dental enamel or collagen from dentine. The ratio between heavier and lighter atoms of carbon and nitrogen gives us information about a person’s diet, whereas the ratio between heavier and lighter atoms of strontium are determined by where someone lived when their teeth were forming.

For example, the isotopic analysis of tooth enamel using strontium could identify if a person was born in a region in West Africa, then went to another chemically distinct area such as Barbados. Or moved from the US to the UK, for that matter.

By combining the multiple lines of evidence gathered from research performed by Marcela, Erna, and Judy on a single individual, archaeologists can start to understand more precise geographic characterizations, even within a highly mobile population such as what was present in West Africa during the Trans-Atlantic Slave Trade.

Another scientist at the table in the pub was Jessica Hendy, a New Zealander based at the University of York, who is looking at health and disease in enslaved populations from a molecular perspective. Using the same burials from Saint Helena, Jessica is trying to identify the remains of diseases present among the liberated Africans. She is combining aDNA analyses with ancient proteomics, the study of ancient proteins. Though ancient proteins are more stable than aDNA — DNA chains degrade ten times faster than ancient proteins — the study of ancient proteomics has lagged behind. But with the development of sensitive new instruments, ancient proteomics is being used to identify the different bacteria that may have caused diseases, as well as specific immune responses. While on the hunt for these diseases, Jessica has also found evidence of the diet of the liberated Africans.

These details about health, ethnic origins and diet can help re-humanize individuals in a population that has been conglomerated through the brutality of history into a indistinguishable mass of anguish.

The immediacy of personalized accounts of enslaved individuals are particularly resonant. With recent movies such as 12 Years a Slave and Django Unchained, ongoing debates about reparations for slavery, and the relentless, systemic violence, brutally manifest in the recent shooting of Michael Brown in Ferguson, Missouri, research that highlights inequities through personal accounts can provide context for modern injustice.

To locate individuals in the historical record, Brazilian historian and EUROTAST fellow Carlos da Silva has been sifting through the ledgers made by slavers as they loaded their ships with captives to be brought to the New World. These ledgers include the age, height, sex, ship name, year, where the enslaved people were taken on board and then dropped off, and a name. These names have been the primary vehicle for investigation of the origins of black ancestry. Alex Haley wrote about his search for African origins in Roots: The Saga of an American Family:

Yeah, boy, dat African say his name was “Kin-tay”!… He say de guitar a “ko,” de river “Kamby Bolongo,” an’ he was choppin’ wood to make hisself a drum when dey cotched ‘im!’
I explained to her [Cousin Georgia] that I wanted to try to see if there was any way that I could possibly find where our “Kin-tay” had come from… which could reveal our ancestral tribe.
The thought made me feel something like… My God!”

These names are linked to individuals, but investigating the names for clues toward the ethnicity of enslaved Africans can be difficult. The names, when legible, are transliterated and the slavers writing down names failed to hear nuances in pronunciation which resulted in badly mangled phoneticizations. What is left can be difficult to connect to recognizable names of the period.

Professor Kodzo Gavua, University of Ghana, speaking at a EUROTAST meeting

In EUROTAST workshops in Ghana and Senegal, Professors Kodzo Gavua and Ibrahima Thiaw examined these ledgers, finding names that had clear ethnic origins, but also some anomalies. One of the enslaved Africans gave his name as “You are My Master,” thus ensuring that any future owners would unwittingly pay homage to him. There were several names that were linked to social relations, such as “smallest boy in the group” and “one twin.”

In a particularly emotional moment, Ibrahima recognized a name — the name of his grandmother.

This other woman was not related to him, but the implication could not be missed: the Trans-Atlantic Slave Trade reached into the lives of millions — millions of people with names and families, and severed them from their loved ones.

Yet research into the genetics and complicated history of the Trans-Atlantic Slave Trade also reveals the resilience and acumen of these individuals. One such case is that of Hans Jonatan, an unlikely but important ancestor of nearly 500 Icelandic people. Born into slavery in 1784 on a sugar plantation in St. Croix, a Danish colony in the Caribbean, Hans Jonatan was transferred to Copenhagen, where he was mistreated by slave holder Henriette Catharine Schimmelmann. Escaping this ill-treatment, Jonatan joined the Danish Navy where he excelled in battle. Upon his return, he was once again retained by Schimmelmann. His enslavement was at the center of a lengthy historic court case that tested the then newly passed abolition legislation in Denmark. Did Jonatan’s stay in Denmark set him free, or did his birth in the Danish West Indies make him a slave regardless? In his case, the judge ruled that slavery was still illegal in Denmark, but that Jonatan would go back to St. Croix as Schimmelmann’s property.

Jonatan then disappears from Danish history. Two centuries would pass before authorities in Copenhagen would learn his whereabouts. As we now know, Jonatan turned up in a tiny port in East Iceland, having escaped slavery by setting sail on an outgoing ship. He married an Icelandic woman, Katrín Antoníusdóttir, and lived until 1827.

Jonatan fathered three children, two of which survived and became respected citizens of the community. It is not known how he or his children were perceived by this community of Icelanders, many of whom had never seen a “Negro.”

The case of Hans Jonatan, his life and eventual ancestors, demonstrates the complicated genetic legacy of the Trans-Atlantic Slave Trade, and challenges perceptions of historic ethnic purity. In Iceland, genealogical records stretch back 1,000 years. Roughly 40,000 Icelanders have had their genotypes sequenced. This combination provides a unique example of a historic record that can be compared to genetic results. At DeCode Genetics, near the University of Iceland in Reykjavik, I met with computer scientist and EUROTAST fellow Anuradha Jagadeesan, who is tracing Jonatan by an unusual method — through the remains of his genotype found in his ancestors.

As we ate our Icelandic lunch of smoked herring in the airy cafeteria at DeCode, Anuradha explained that the descendants of Jonatan each retain a legacy from their ancestor — there are very few examples of African admixture in the Icelandic gene pool. Anuradha is identifying these shared genetic fragments, and then using them to reconstruct the genome of Jonatan. Through the construction of a vastly complicated algorithm, Anuradha hopes to not only reconstruct Jonatan’s genome, but then to use this genome to identify Jonatan’s phenotype and biogeographical ancestry. If Anuradha is successful, she will set the standard for the use of genetics to better understand the temporal fragmentation of the genome. The ability to retroactively reconstruct individual ancestral genomes from descendant communities will be within reach.

Anuradha Jagadeesan, EUROTAST fellow

Anuradha’s research does not rely on the presence of the skeletal remains of Hans Jonatan, but it is unique in this respect. Though some aDNA research is conducted on domesticated plants and animals, most of this research is closely linked with bioarchaeology, the study of human remains.

Perspectives regarding bioarchaeology are tied to geographic region and ethnicity, but there is a growing global awareness of the contested nature of research on human remains. This is especially prevalent in archaeological research in the United States and Australia, where the removal and storage of the human remains of indigenous people was performed without the consent of their descendants. Reflecting concerns over the cultural patrimony of Native Americans, in the United States the Native American Graves Protection and Repatriation Act (NAGPRA) was enacted in 1990, which establishes the rights of indigenous descendants to human remains, including the ability to reclaim previous collections of human remains.

The World Archaeological Congress code of ethics states that “respect for the mortal remains of the dead shall be accorded to all, irrespective of origin, race, religion, nationality, custom and tradition” and “respect for the wishes of the dead concerning disposition shall be accorded wherever possible, reasonable and lawful, when they are known or can be reasonably inferred.”

Research on the remains of enslaved Africans has further implications. Even beyond the auspices of slavery, the bodies of people of African-descent have been scrutinized and exploited by scientists who reflected racist, colonialist attitudes of their time. In life, Saartjie Baartman was examined by scientists and displayed to a paying public as the Hottentot Venus.

In death, Saartjie Baartman was dissected by Georges Curvier who preserved her genitalia under a bell jar.

Later, from 1932–1972, the Tuskegee Syphilis Experiment involved research on impoverished African American sharecroppers to track the progression of syphilis, with the penicillin cure withheld by researchers for decades. This outrageous experiment was conducted by the U.S. Public Health Service. It is widely cited as leading to the establishment of institutional review boards that monitor subject participation in research.

Resistance against the exploitation of the bodies of black people for scientific research came to the fore with the excavation of the New York African Burial Ground in the early 1990s. After sharp, protracted community resistance to the excavation of over 400 African and African-descent burials at what was marked on historic maps as the “Negroes Burial Ground,” Michael Blakey from Howard University took over archaeological investigation of the site. In contrast to descent communities that abjure any analyses that require the destruction of human remains, the burials were shown respect by the extensive analyses performed by Blakey and his team. The descendant community required a detailed analysis of the cultural background of the Africans, including bone and dental chemistry analyses in order to preserve the Africans as individuals.

EUROTAST research on the African burials on Saint Helena followed the example established by Michael Blakey and his team at the New York African Burial Ground. A tiny, windswept, outcropping of basalt, Saint Helena is known primarily for the exile and eventual death of Napoleon, who called the island a “cursed rock.” One of the most remote places in the world, Saint Helena can only be reached by a monthly mail ship or private yacht. In anticipation of the construction of a new airport, Dr. Andrew Pearson conducted extensive excavations in Rupert’s Valley, where the Africans liberated from slave ships were landed at a depot.

In terrible condition from their kidnapping, torture and confinement, many died and were buried in the valley. After the conclusion of the excavations at Rupert’s Valley, EUROTAST fellows Erna and Judy travelled on the mail ship to Saint Helena to examine the excavated burials. Erna took impressions of modified teeth, while Judy selected two teeth from each skeleton for destructive aDNA analyses.

Judy struggled while she worked with the collection of human remains from Rupert’s Valley. The violence suffered by the liberated Africans before their death was visible on the bones. They had a panoply of diseases — anemia, scurvy, infections, and were heartbreakingly young. Slavers favored children and young adults for their resilience and the value of a long life spent working. Judy’s task had further complications as selecting human remains for destructive analyses is an imprecise process. While archaeology is known as a destructive science — as Kent Flannery stated,

“Archaeology is the only branch of anthropology where we kill our informants in the process of studying them”

— selecting parts of a human body to pulverize to extract a sample is very different than tearing down an ancient wall with a pickaxe. Unhelpfully, the visual appearance of a tooth may have no connection to how much DNA can be extracted from it.

As techniques in processing aDNA rapidly improve, processing samples immediately or waiting for six months for better results can be a fraught decision. While gathering the teeth from the Saint Helena collection, the fellows gave a museum talk about their research goals to the community. During this talk, Judy spoke of her anxiety to the audience:

“There is a decision making aspect to try to figure out what are the most likely teeth to yield DNA. I don’t want to leave here without being able to identify people. It would be heartbreaking to get back and find out that a tooth was not very good for DNA.”

To mitigate the problems with destructive analyses, the researchers working with the Saint Helena samples tested a strategy that would minimize the amount of material they needed to extract and are strategically sharing data so that the destructive tests will not have to be repeated. In this case, the violence of the Trans-Atlantic Slave Trade can be partially addressed by identifying details about individuals, such as their origins and their ethnic identity. Finding this balance between scientific inquiry and the diverse interests of descendant communities is incredibly important for ethical archaeological research.

The intricacies of conducting research on aDNA, ethnic origins, and the Trans-Atlantic Slave Trade become more obvious when similar research is misappropriated to present reductionist ideas about race. Even after developing a strategy that involves minimal destruction of remains and reflects the best research methodologies possible to better serve the descendant community, this research can misused. Nicolas Wade’s recent book, A Troublesome Inheritance: Genes, Race, and Human History, links differences in behavior and societies to human evolution and genetics. Wade’s charge that geneticists are reluctant to discuss their results because of political sensitivity is only partially true — geneticists are reluctant to discuss results because these results may be misappropriated by popular journalists such as Wade.

Anthropologists around the world objected to Wade’s characterization of social behavior as derived from genetics. The American Anthropological Association hosted an online debate between Nicholas Wade and Augustín Fuentes, a professor of anthropology at Notre Dame. During this debate Fuentes challenged Wade to provide a biological definition of race. Wade did not respond. A final, stunning censure was delivered by over 100 faculty members in population genetics and evolutionary biology who stated that:

“there is no support from the field of population genetics for Wade’s conjectures.”

The misappropriation of research based on genetics, ethnic origins, and archaeological remains can be addressed by direct action, such as the actions taken by academics against Wade. This approach is effective, but is a reaction rather than a preemptive consideration of potentially harmful misinterpretation. To better understand the impact of genetic research, EUROTAST fellow Sarah Abel is examining the social context of the legacy of the Trans-Atlantic Slave Trade.

Sarah Abel, conducting an interview for her research on ancestry genetics testing.

Sarah, a gifted polyglot from England, is an anthropologist based at the Centre International des Recherches sur les Esclavages (CIRESC) in Paris, but conducts her ethnographic research in the United States and Brazil. Sarah examines the increasingly inexpensive and popular genetic ancestry tests, such as those offered by 23andme and ancestry.com, to understand the social impact of genetics testing on ethnicity and identity in post-slavery societies. Sarah’s research methodology involves holding interviews about genetic ancestry tests. She conducts an interview before the subject takes the test and then again after the results have returned.

Her questions are direct — she asks if “the experience of taking a DNA ancestry test made you think differently about your identity, or other people’s identity?” and “Do you think DNA ancestry tests can tell us anything about ‘race’, or is that something different?” In this way, Sarah can understand current perceptions of race and genetics and provide context to the studies conducted on aDNA and the Trans-Atlantic Slave Trade.

Sarah’s questions reveal how population genetics are shifting how we understand our origins. As an archaeologist, I was accustomed to digging up houses and pots and speaking with local communities about the people who used to live there. Sometimes there appeared to be remarkable continuity in how people were using the various landscapes where I worked, re-using Roman roads, building out of mudbrick, collecting salt for offerings. There was the frisson of familiarity, recognition, and excitement about the past.

More often archaeologists echo David Lowenthal’s sentiment, that the past is a foreign country, and that these connections to the past, like memories, are “eclectic, selective reconstructions.” So what does it mean when we share genes with those people who dwelled in the “foreign country” of the past? Yet Hannes Schroeder, one of the directors of EUROTAST reminds us that:

“at the end of the day, DNA isn’t the only answer. It is just another document for us to use to compare and consider the past.”

The EUROTAST fellows have not finished their research; there are still tests to run, ethnographies to write, articles to publish. The evidence that Marcela, Erna, Judy, and Jessica have for the origins and lives of the liberated Africans buried on Saint Helena provide a strong foundation for building new stories about the individual struggle of people under slavery.

The perspectives that population genetics, computer science, history, and social anthropology can bring to questions about ethnicity, origins, diet, and the impact of the Trans-Atlantic Slave Trade is welcome and necessary in archaeological research. As advances in aDNA research bring us face-to-face with more of our ancestors, building collaborative teams that have a strong connection to descendant communities and an understanding of the personal and political impact of research on heritage and origins is vitally important.