NEW YORK (GenomeWeb) – Genomic analysis may be able to inform efforts to return remains from indigenous peoples to their homes.
After European colonization, the remains of many indigenous people were collected for both scientific research and to be displayed in museums. This has led in recent years to calls by Native Americans and Aboriginal Australians for these remains to be repatriated.
As researchers led by Griffith University's David Lambert noted, this is of special importance to many Aboriginal Australians who believe their ancestors' remains must return to their ancestral lands for their spirits to rest.
Lambert and his colleagues noted that as many Aboriginal Australian remains in museum collections are poorly labeled, it's unclear exactly from where they originated. However, he and his colleagues have now reported in Science Advances that genomic analysis comparing ancient remains to genome sequences of present-day Aboriginal Australians may be able to determine where the remains originated.
"We propose that our approach can be used now and will be used routinely in the future to return remains to their rightful kin," the authors wrote in their paper.
The researchers assembled 27 sets of ancient Aboriginal Australian remains from archeological excavations of burial sites and previously repatriated remains of known provenance. All the remains are older than European contact with Australia and should have no marks of European admixture.
For all the samples, the researchers sequenced their mitochondrial genomes to between 2.3X and 321X coverage. At the same time, they generated 10 nuclear genomes to between 0.3X coverage and 6.9X coverage. For four male samples, they also generated partial or full Y-chromosome sequences.
These ancient Aboriginal Australian sequences then served as proxies for unidentified remains in the researchers' analyses.
The researchers compared these ancient Aboriginal Australian sequences to a set of 112 mitochondrial and 100 nuclear genome sequences from present-day Aboriginal Australians with known language group and geographic relationships.
Using just mitochondrial DNA data, the researchers constructed a maximum likelihood phylogeny that revealed 38 distinct mitochondrial haplogroups. From this, they could match nine ancient individuals to a modern individual within 100 kilometers, and six ancient individuals could be matched to an exact location.
However, for 11 ancient individuals, the results were inconclusive. For one individual in particular, the closest present-day matches were from opposite sides of the Cape York Peninsula, which the researchers noted was a distance of 635 kilometers. Based on this, they concluded mitochondrial DNA alone isn't enough to determine where to repatriate ancient remains. They further estimated that if mitochondrial sequences alone are used, about 7 percent of remains would be returned to an incorrect Indigenous group.
The researchers turned to their set of nuclear genomes. Through a series of principal components and out-group f3 statistical analyses, they examined the genetic relationships between the ancient Aboriginal Australians samples, which uncovered substantial genetic structure.
When they then compared their ancient Aboriginal Australian samples to their modern ones, the researchers noted a high degree of genetic affinity between ancient and modern groups from the same geographic region, as compared to other regions. This, the researchers noted, suggests long-term population continuity.
It further could help with identifying the proper places where remains should be repatriated.
"Our findings demonstrate the feasibility of successfully identifying the origins of unprovenanced ancestral remains using genomic methods," the researchers wrote.
They added that this approach could also help identify from where members of the Stolen Generation — Aboriginal Australian individuals who were taken from their homes as children to be placed with European families or in institutions — originated. The approach could also be applied to aid in the repatriation of remains from other groups around the world, including Native Americans.