Lineage separation· Where Sapiens lives

The Australasian lineage separates

68 ka

The ancestors of Aboriginal Australians and Papuans part from the rest of the out-of-Africa lineage, early enough to be crossing open sea towards Sahul while the other branches are still together.

What the evidence shows

The genomic estimate rests on 83 Aboriginal Australian and 25 Papuan high-coverage genomes, and puts the divergence from Eurasians between 72,000 and 51,000 years ago, following a single departure from Africa. What happened next was not a single people spreading over a continent. Papuan and Aboriginal Australian ancestors had already parted 40,000 to 25,000 years ago, which means Sahul held structured populations well before the seas rose to cut it in two. The mitochondrial evidence, drawn from 2,456 genomes, points to at least two distinct routes in rather than one.

Dating & uncertainty

Where this branch belongs is genuinely disputed, and the timeline takes a side. Lipson and Reich's working model nests Australasians inside the eastern clade, which would place their separation after the east-west split rather than before it. Genome-wide estimates for their divergence from Eurasians span 72,000 to 51,000 years ago. The early separation is drawn because it is the only arrangement compatible with people reaching Sahul 65,000 years ago; the Neanderthal admixture shared by all non-Africans at 49,000 to 45,000 years ago pulls the other way. The tension is not resolved.

Sources

1. Malaspinas, A.-S. et al. (2016), Nature · A genomic history of Aboriginal Australia
2. Lipson, M., Reich, D. (2017), Molecular Biology and Evolution · A working model of the deep relationships of diverse modern human genetic lineages outside of Africa
3. Gandini, F. et al. (2025), Science Advances · Genomic evidence supports the “long chronology” for the peopling of Sahul
4. O'Connell, J. F. et al. (2018), PNAS · When did Homo sapiens first reach Southeast Asia and Sahul?
5. Sümer et al. (2024), Nature · Earliest modern human genomes constrain timing of Neanderthal admixture