Ethical challenges in ancient DNA research have global reach

The complex ethics of human history

Readers are advised that this article contains images of ancient human remains.

At the end of this century’s first decade, no ancient human genome had been sequenced in full. Now, there are over 6,000 complete genomes in the archives, and more are added to the list every week.

Since it became clear that DNA could be extracted from things long since dead, scientists around the world have raced to do it on human remains. In the past year alone, genetic research has been published on a 45,000-year-old human skull from Czechia, the Tarim Basin mummies in north-western China, the Pacific migrations, and Japanese ancestry.

While the research has gone global, the implications of it are deeply local. Ancient DNA research can show much about the history of a culture, but it’s also possible that the genetic data, and its collection, is of no benefit – or even some detriment – to the place it came from.

Aerial view of archaeological site in desert
Aerial view of the Xiaohe cemetery, site of the Tarim basin mummies. Credit: Wenying Li, Xinjiang Institute of Cultural Relics and Archaeology.

To start with, some samples must be destroyed to extract DNA. And unique human genomes yield far more culturally complicated knowledge than even bones do: DNA is irrelevant to some, valuable historic information to others – or, concerningly, even something like a proxy for the human soul.

Where should genetic data be stored? How can real, informed consent be obtained from local Indigenous groups to collect it? How should the information learnt be shared?

Researchers were asking questions about the ethics of ancient human DNA years before the first complete ancient genomes were sequenced. With varying levels of urgency, different countries have begun to develop norms for handling ancient DNA – but as yet, there are no international core rules.

Ancient DNA research can show much about the history of a culture, but it’s also possible that the genetic data is of no benefit – or even some detriment – to the place it came from.

Twelve months ago, a group of over 60 archaeologists, anthropologists, curators and geneticists, Indigenous and non-Indigenous, from 31 countries, attended an online meeting to address this gap. Publishing their decision in Nature in October, the researchers described five “globally applicable guidelines” for research on ancient human DNA:

  1. Researchers must ensure that all regulations were followed in the places where they work and from which the human remains derived;
  2. Researchers must prepare a detailed plan prior to beginning any study;
  3. Researchers must minimise damage to human remains;
  4. Researchers must ensure that data are made available following publication to allow critical re-examination of scientific findings; and
  5. Researchers must engage with other stakeholders from the beginning of a study and ensure respect and sensitivity to stakeholder perspectives.

“The idea was to eventually have a set of guidelines that could be used by people anywhere in the world,” says co-author Associate Professor Bastien Llamas, an ancient DNA researcher at the University of Adelaide.

“Of course, the will to make it global meant that some people find it very shallow in the sense that these guidelines are quite broad in scope and need to be adapted to local situations.”

The Nature paper was not met with global approval. Appearing first on social media and then in other venues (including a recent correspondence in Nature), a number of ancient DNA researchers voiced criticisms of the paper.

“There are key perspectives that are missing from this paper,” says Associate Professor Deborah Bolnick, an anthropological geneticist at the University of Connecticut, US.

“Few scholars with formal training and expertise in bioethics, community engagement, Indigenous studies, settler colonial histories, and critical science and technology studies were involved in this effort. That expertise is critically important here, and it is concerning that it was excluded given the topics being addressed.”

There was an explicitly political angle to the paper. Much of the previous work on ancient DNA ethics has been done in the United States, and the paper (which has US co-authors) pointed out several times that those cultural norms were not necessarily the best fit for the rest of the world.

“There are key perspectives that are missing from this paper.”

Deborah Bolnick, University of Connecticut

“The guidelines that exist now have been formulated in very specific situations, which are first-world countries with indigenous minorities, where the indigenous minorities don’t generally have much power,” says paper co-author Emeritus Professor Matthew Spriggs, an archaeologist at the Australian National University.

The American Society of Human Genetics adopted five of its own ancient DNA guidelines in 2020, making it one of the first research organisations to do so.

“Those [US] guidelines are not universally applicable in any way,” says Spriggs. “They’re very legalistic. And they require written formal agreements that in many parts of the world are just not how things are done.

“There’s a whole different way that you have to approach communities, which is a much more intensive and a much more informal process.”

Spriggs – who has lived and worked as an archaeologist in Vanuatu for four decades – says that written agreements would be a deterrent to his research there, which relies on verbal work and trusted local collaborators.

“We’ve had 40-plus years of very dedicated, interested local people, collaborating often in a long-term relationship with researchers. And so, things are quite easily explained, but in this very informal manner.”

Spriggs’ experience is not unique among the papers’ authors. “We have had multiple experiences of writing papers about ancient DNA from Central and South America and receiving reviews stating the work did not conform to standards for Indigenous engagement developed in the USA,” reads one paragraph.

“Those of us who are from Mexico and Central and South America have felt that such reviews have been paternalistic at best and colonialist at worst.”

Lateral view of the mostly-complete skull of zlatý kůň - the oldest human genome.
Lateral view of the mostly complete skull of Zlatý kůň, who was found in Czechia and provided possibly the oldest human genome sequenced to date. Credit: Martin Frouz.

A central cultural difference is the meaning of indigenous.

“Identifying as indigenous varies around the world, depending on recent history,” says Llamas.

“The colonial history is not the same everywhere you go in the world. And there’s definitely differences that need to be taken into account.”

Spriggs is less polite. “Let’s give the obvious example: people in Germany – what is the ‘indigenous’ group? Who are the people who are most concerned about it? Well, they might actually be people like neo-Nazis.”

It’s unsurprising that a work explicitly distancing itself from US policies would draw criticism from US researchers.

“I note that so many of the reactions come from people inside the United States – telling the rest of the world what to do,” says Spriggs.

“Those [US] guidelines are not universally applicable in any way.”

Matthew Spriggs, Australian National University

But while many of the objections were North American, this theme was not their chief criticism of the paper. Bolnick, for instance, takes issue with the wording around guidelines (4) and (5).

“[These guidelines] are deeply concerning to me because they could actually serve to limit the input and influence of indigenous, descendant, or other stakeholder communities,” she says.

“The authors say that: ‘Once a consensus to proceed has been reached, professional scientific ethics requires that researchers are able to pursue their work up to the point of publication without requiring further approval.’ They do not cite a source for that assertion, though, and I am not aware of any ethical standards that actually state that.

“This assertion serves to concentrate power over scientific data in the hands of the scientists, and gives scientists sole authority to decide how to interpret the data and whether/how to publish.”

Llamas has a slightly different view, seeing data sovereignty as both one of the core universal values of ancient DNA work, and implicit in the paper.

“If you work with a community that defines itself as an indigenous entity, the data is theirs. You can’t claim ownership of this kind of data, because they’re theirs. Sovereignty is really the community’s.”

The other chief criticism is that the guidelines don’t go far enough.

“The guidelines proposed in this recent publication are quite basic,” agrees Bolnick.

“Most have been suggested previously by ethicists, Indigenous scholars, and critical scientists and social scientists, and have been part of standard scientific practice in this field for a long time. It therefore seems odd and a little disingenuous to present them as novel.”

Neither Spriggs nor Llamas believe that the guidelines will add anything new to their own work – but that doesn’t mean they’re unimportant. Rather, they believe that they were already meeting these ethical standards, and they now have a better way of articulating them.

For Spriggs’ work in Vanuatu, for instance, getting consent for ancient DNA work is community-led. “I turn up in a community and they know who I am, they know all the good things about me, and all the bad things about me,” he says.

“You go to the nakamal, which is like the community house, a community gathers, they have a discussion, you may go away again and come back some months later […] They say ‘actually, we think we need more time – come back in another three months’ time’ or ‘come back next year’. Or they may say, ‘look, we’ve been thinking about it and actually, we really don’t think this is what we want’. And you just go away.”

“There’s got to be a framework in which people can work, and then the moving target is probably going to be adaptations to local context.”

Bastien Llamas, University of Adelaide

Llamas’ work, in South America, begins with similar aims. “There’s going to be some people from that community who are going to work very closely with you in terms of data generation, in terms of interpretation, and [storage]. So making sure that there’s going to be training of people, there’s going to be appropriate equipment [in the local community].”

If these practices are already happening, but they differ based on local context, is it necessary at all to have international guidelines? This question, at least, appears to have a consistent answer among researchers on and off the paper: yes. There have been calls from a variety of researchers for more consistent international standards.

“I do think there is a critical and urgent need for clearer and more detailed guidance to ensure that DNA research on human ancestors is conducted as ethically as possible,” says Bolnick.

“There’s got to be a framework in which people can work,” says Llamas. “And then the moving target is probably going to be adaptations to local context.

“But there are definitely universal values and ways of doing things that should be respected all the time. Simple things like, for example, minimizing the damage done to human remains.”

But while Llamas thinks this paper is moving the field forward, he also thinks it hasn’t yet answered this demand.

“Our paper is the [most recent] of a list of papers of importance in the ethics of ancient DNA in relation to Indigenous populations,” he says.

“These should not be taken as the ultimate guidelines. This is really the product of a meeting between 60-odd researchers but still, it’s not a comprehensive list of researchers. Many, many researchers were not part of this.”

Adding more voices to the discussion will improve ethical guidelines – even if it makes it harder to reach consensus. “My hope is that in the future, there’s going to be many more of those workshops, [they’ll be] more and more inclusive with people from all sorts of backgrounds and disciplines as well,” says Llamas.

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