Lineage separation· Where Sapiens lives

The Australasian lineage separates

68 ka

About 65,000 years ago, the ancestors of Aboriginal Australians and Papuans separated from the rest of the lineage that had left Africa, early enough to cross open sea to Sahul, a placement still disputed.

Separation of the ancestors of Aboriginal Australians and Papuans from the rest of the lineage issuing from the exit from Africa, early enough for them to cross 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 places the divergence from Eurasians between 72,000 and 51,000 years, following a single departure from Africa. What followed is not the diffusion of a single people across a continent. Papuan and Aboriginal ancestors had already separated 40,000 to 25,000 years ago, which implies that Sahul carried structured populations well before rising sea level divided it in two. An analysis of 2,456 mitogenomes indicates at least two distinct entries and not one.

Dating & uncertainty

The position of this branch is genuinely disputed, and the timeline adopts one option. The working model of Lipson and Reich places Australasians within the eastern clade, which would situate their separation after the east-west bifurcation and not before. Genome-wide estimates for their divergence from Eurasians range from 72,000 to 51,000 years. The early separation is represented because nothing else is compatible with an arrival in Sahul 65,000 years ago; the single episode of Neanderthal admixture shared by all non-Africans, at 49,000 to 45,000 years, points the other way. The contradiction is unresolved.