Genomic evidence supports the "long chronology" for the peopling of Sahul

Abstract

The timing of the settlement of Sahul—the Pleistocene landmass formed by present-day New Guinea, Australia, and Tasmania that existed until ~9000 years ago (~9 ka)—remains highly contentious. The so-called “long chronology” posits the first main arrivals at ~60 to 65 ka, whereas a “short chronology” proposes 47 to 51 ka. Here, we exhaustively analyze an unprecedentedly large mitogenome dataset (n = 2456) encompassing the full range of diversity from the indigenous populations of Australia, New Guinea, and Oceania, including a lineage related to those of New Guinea in an archaeological sample from Wallacea. We assess these lineages in the context of variation from Southeast Asia and a reevaluation of the mitogenome mutation rate, alongside genome-wide and Y-chromosome variation, and archaeological and climatological evidence. In contrast to recent recombinational dating approaches, we find support for the long chronology, suggesting settlement by ~60 ka via at least two distinct routes into Sahul.