Origins of the Australian and New Guinean Aborigines

Abstract

Abstract Mitochondrial deoxyribonucleic acid (mtDNA), Y chromosome and limited genomic studies indicate deep ancestry for both Australia and New Guinea peoples, with evidence for limited, shared genetic connection as well as ancient lineages specific to both places. Estimates of divergence from the Revised Sapiens Reference Sequence (Behar et al. , 2012) indicate that mtDNA haplogroups of living populations in Melanesia and Australia represent some of the oldest lineages outside Africa, founders having arrived there at least 50 000 years ago. Several entry points into Sahul during periods of glacial maxima might explain haplotype distribution. Distinctions between them and other near neighbours also indicate genetic isolation for long periods after sea levels rose. Phylogenies that explore genetic similarities/differences between peoples of Sahul and Asia suggest that migration routes through northern Asia as well as by a southern coastal route are likely scenarios, as no single regional source population is identifiable. Key Concepts: Australia and New Guinea were connected by a land bridge during periods of global glaciation forming a land mass known as Sahul, separated from Sunda. Evidence indicates that people arrived in Sahul approximately 50–60 thousand years ago. After the Last Glacial Maximum (LGM), Australia and New Guinea were gradually separated and the populations were relatively isolated from each other. People dispersed throughout the Australian continent by 40 thousand years ago. Participation in genetic research by descendants of the ‘First Sahulians’ is relatively rare and they are under‐represented in global studies. There is resistance from some descendants of the First Australians for many reasons including distrust generated by poor research practices of the past. Studies that include indigenous researchers as well as participants are likely to encourage, facilitate and improve representation. Those Aboriginal Australians who have participated in genetic research have contributed valuable data that enrich the global story of human diasporation and their own communal and personal history. Mitochondrial DNA (mtDNA) and Y‐chromosome analyses are particularly suitable for exploring recent human genetic history, whereas genome‐wide analyses are necessary for probing more deeply into population origins. Complex population histories in Asia suggest different scenarios for likely routes and entry points for founding groups in Sahul.