A comprehensive analysis of microsatellite diversity in Aboriginal Australians

Indigenous Australians have a unique evolutionary history that has resulted in a complex system of inter and intra-tribal relationships. While a number of studies have examined the population genetics of indigenous Australians, most have used a single sample to illuminate details of the global dispersal of modern humans and few studies have focussed on the population genetic features of the widely dispersed communities of the indigenous population. In this study we examine the largest Aboriginal Australian sample yet analysed (N = 8,868) at fifteen hypervariable autosomal microsatellite loci. A comprehensive analysis of differentiation indicates different levels of heterogeneity among indigenous peoples from traditional regions of Aboriginal Australia. The most genetically differentiated populations inhabit the North of the country, in particular the Tiwi of Melville and Bathurst islands, Arnhem Land (itself divided into West and East Arnhem), and Fitzmaurice regions. These tribal groups are most differentiated from other Aboriginal Australian tribes, especially those of the Central Desert regions, and also show marked heterogeneity from one another. These genetic findings are supportive of observations of body measurements, skin colour, and dermatoglyphic features which also vary substantially between tribes of the North (e.g. Arnhem Land) and Central Australian regions and, more specifically, between the Tiwi and West and East Arnhem tribes. This study provides the most comprehensive survey of the population genetics of Aboriginal Australia.