The remains of Indigenous Australians — taken from their resting places after European colonization — could now be returned, with help from ancient-DNA sequencing techniques.

In a 19 December paper ¹ in Science Advances , researchers showed that they could accurately match DNA from ancient Aboriginal Australian remains to modern inhabitants from the same geographical area. The research could enable the repatriation of the hundreds, if not thousands, of Indigenous Australian remains in museums that lack documentation indicating their origins.

“This paper is really an incredible step forward in the story of repatriation. It’s really, really exciting work and a major advance,” says Emma Kowal, a cultural and medical anthropologist at Deakin University in Melbourne, Australia. “This sets out a lot of work for museums, but also gives Aboriginal communities hope that they are going to be able to identify more of their ancestors and get them home.”

Undoing wrongs

After their arrival in 1788, European colonists removed thousands of human remains and sacred objects from Aboriginal burial sites, dispersing them to museums in Australia, Britain, Germany, North America and elsewhere.

The first Indigenous Australian remains were returned in 1976 and repatriation of these remains and objects is part of Australian government policy. So far, more than 2,500 sets of human remains and 2,200 sacred objects from Australian museums have been returned to their communities of origin, according to the government office responsible for these efforts. Australia has also repatriated around 1,500 human remains from international collections.

Decades of efforts to repatriate remains of known provenance has meant that a growing proportion of indigenous remains still held in museums lack the documentation necessary to return them to the appropriate Aboriginal Australian group.

“Years ago, if someone found Aboriginal remains in Australia, they put them in a cardboard box and left them in the back steps of museum. Hardly ever did they have any detail where they came from,” says David Lambert, an evolutionary geneticist at Griffith University in Nathan, Australia, who co-led the study with population geneticist Martin Sikora at the University of Copenhagen.

It is vital to many Aboriginal groups that human remains be reburied in their ancestral home — known as Place and Country. “You would most certainly never want to repatriate remains to a Place and Country that was wrong,” Lambert adds.

A 2014 report from the Australian government’s Advisory Committee for Indigenous Repatriation recommended the establishment of a national resting place for remains whose exact provenance is unknown. This site would be located in Canberra, adjacent to the country’s parliament.

DNA decisions

A team led by Lambert and Joanne Wright, an ancient DNA researcher at Griffiths University, obtained DNA from 27 ancient Aboriginal remains with known origins. The team — which includes representatives from the Aboriginal groups that now hold the remains — recovered partial or full nuclear genomes from ten specimens, the first ancient nuclear genomes ever recovered from Australia. The researchers also sequenced mitochondrial DNA, which is present in larger quantities in bone and inherited maternally, from 27 remains.

Next, the researchers tried to match the genomes of each set of human remains to nuclear and mitochondrial genomes from 100 modern Aboriginal Australians from different parts of the country. For the ten sets of remains for which nuclear data were available, the closest matches were to individuals from the regions where the remains were known to have originated.

But comparisons made using mitochondrial DNA proved to be less accurate. For 11 individuals, there was no conclusive match to information in a database of 112 individuals — either because the mitochondrial sequence was widespread in Australia, or there was no match in the database of contemporary DNA.

And two sets of ancient remains were matched to the wrong geographical area when mitochondrial DNA was used.

That means that unprovenanced remains should be matched using nuclear DNA, says Lambert. His team hopes to grow its database of contemporary genomes to improve the chances of finding a match. Adding ancient human genomes from remains whose provenances are known will help. But, says Lambert, “we’ve got to accept that as we start to do more of this work, we might find examples where it doesn’t work, or it’s not as accurate as we like”.

Alan Cooper, a palaeogeneticist at the University of Adelaide in Australia, notes that the matches between ancient remains and contemporary individuals presented in the paper were very close. “This is the ideal situation,” he says. If remains come from regions where there are no contemporary genome data, it will be much more difficult to find a match, he says. Cooper’s team plans to address this challenge by sequencing the genomes of around 7,000 hair samples, collected by anthropologists between the 1920s and 1970s, in collaboration with Aboriginal communities .

Lambert’s team hopes to test its approach soon on remains from the Queensland Museum in South Brisbane, before expanding to other Australian museums and, eventually, to international collections, such as those at the British Museum. “Aboriginal people can’t wait any longer for this sort of work,” says Lambert, who considers this paper to be the most important of his career.

Ancient One

Ancient DNA might also allow for the return of indigenous remains in other countries, says Lambert. A US federal law called the Native American Graves Protection and Repatriation Act, for example, mandates the return of remains and artefacts to groups that can demonstrate a connection to them.

In 2017, a 8,500-year-old skeleton known as Kennewick Man or Ancient One was returned to Native American communities in Washington state that had been seeking repatriation, after DNA sequencing determined that the remains were Native American and therefore fell under the jurisdiction of the Repatriation Act .

The oldest US mummy was returned to a Nevada tribe after it, too, was determined using ancient DNA to be Native American in 2016. However, this technique has not yet been used to link specific Native American groups to ancient human remains, under the repatriation law.

Drawing these links depends on determining whether modern Native American populations are closely related to ancient groups from the same region, says Lambert. “We think it would be worth a try.”