title: Return to Country: genomics and the repatriation of ancient Aboriginal Australians
Creators: name: Wright, Joanne Louise
Publisher: name: Griffith University
Year: 2018
Subjects: subject: Genomics
subject: Ancient Aboriginal Australians
subject: Mitochondrial phylogenetics
subject: Chromosome painting symmetry statistics
subject: Repatriation method

description: Since European settlement of Australia in 1788, Aboriginal Australian remains have been deposited in museums worldwide. For the past fifty years Aboriginal Australians have campaigned for their ‘return to Country’. However, for many remains there are no details of their geographic origins, tribal affiliations or language groups, and as a result they cannot be repatriated. This research, undertaken in collaboration with Aboriginal Australian Traditional Owners and communities across Australia, tests whether it is possible to determine the origins of ancient individuals using DNA-based methods. Thirty mitogenomes and 10 nuclear genomes from ancient pre-European Aboriginal Australians of known provenance (up to 1,600 yr BP) were recovered and used as proxies for unprovenanced remains. These ancient genomic sequences were compared against assembled reference datasets of contemporary Aboriginal Australian mitochondrial (n=112) and nuclear genomes (n=100). A number of analytical methods were used to test this potential tool for repatriation including mitochondrial phylogenetics, and nuclear PCA, f3- and f4 outgroup statistics, and chromosome painting symmetry statistics. These analyses showed substantial population structure across Australia. While a distinct east versus west population divide had been observed previously in contemporary Aboriginal Australians, the mitochondrial and nuclear analyses reported here show that this population structure occurs even at a regional level. Mitochondrial phylogenetic analyses revealed the majority of mitochondrial haplotypes observed were region-specific, with novel haplotypes being identified in both contemporary and ancient Aboriginal Australians. However, there were also haplotypes which were widespread being observed in a number of Australian states, in addition to rare haplotypes for which there were no contemporary matches. For these ancient remains it was not possible to determine their origin using mitochondrial DNA alone. The origin of 58.1% of ancient Aboriginal Australians included in this research could be successfully determined using mitochondrial DNA. However, this success was weakened by results obtained for two ancient individuals, with their respective contemporary matches living on the opposite side of Cape York Peninsula in northern Australia. This is problematic as the return of ancestral remains to an incorrect Country is a major concern of many Aboriginal Australian communities. Therefore, given these erroneous results, only detected because their provenance had previously been established, the reliability of using mitochondrial DNA for repatriation is significantly undermined and must be questioned. The most accurate results obtained was using nuclear DNA, working in 100% of cases and to precise geographic locations. These results were supported by a number of different analytical methods, each of which independently showed both population structure and local continuity between both the ancient and contemporary populations in each geographic location. However, when combined, these analyses provide strong evidence that nuclear DNA, as a tool for repatriation, is very effective and if applied to unprovenanced ancestral remains will greatly assist with their repatriation. It is important to note that there are obstacles that need to be overcome before this proposed repatriation method can be put into practice. The first is the cost of completing this type of work. Ancient DNA research is expensive, especially if nuclear DNA is the target of interest, and many museums worldwide will find funding for this sort of research well outside their reach. More significantly though, this DNA –based repatriation tool poses a catch 22 in that the work cannot be undertaken without permission from the appropriate Aboriginal Australian communities, and until the provenance of remains is determined these communities cannot be identified. A proposed way forward would be national level discussions between the Australian Government, Aboriginal Australians, and museums. These discussions would allow all parties to decide how best to move forward and how the tools presented in this research should be utilised. But ultimately, this is a decision only Aboriginal Australians can make. This research provides the means to move forward in the repatriation debate, a debate that has caused many Aboriginal Australians considerable sadness and frustration for decades. If agreement can be reached regarding how it should be implemented, it has the potential to assist in bringing closure to a painful chapter of history for many Aboriginal Australians. While it cannot, and will not correct the mistakes of the past, it may provide healing through the eventual return to Country of many lost ancestors.