During repeated Ice Age sea-level lows, Australia, New Guinea, and Tasmania were connected into the larger landmass known as Sahul. Even at the lowest seas, however, Sahul was still separated from Southeast Asia (Sunda) by island chains (Wallacea), meaning any first arrival required sea crossings.
Homo sapiens groups moved eastward through Island Southeast Asia and reached Sahul by traveling across open water between islands. This step mattered because it implies planned seafaring (boats or rafts) and social coordination, not just walking across exposed land.
Excavations at Madjedbebe (Malakunanja II) in Arnhem Land reported artefacts in secure layers dated to around 65,000 years ago. The finds include stone tools and ground ochre, supporting an early presence of modern humans in northern Australia soon after (or as part of) initial Sahul settlement.
After the Madjedbebe results, scholars continued debating whether the first settlement was closer to ~65,000 years ago or later (often ~50,000–60,000 years ago). This matters because the timing affects how Sahul settlement fits into wider models of Out-of-Africa dispersal and later genetic mixing with other hominins.
Over thousands of years, populations expanded into many Sahul environments, from tropical north coasts to arid and temperate regions. This transition reflects learning new food sources and movement routes, and it set the stage for long-term regional cultural diversity.
The Willandra Lakes Region preserves strong evidence for ancient human life and changing environments in southeastern Australia. Its archaeology demonstrates that people were living well inland, not only along coasts, and that they adapted to lakeshore landscapes that later dried out.
Human remains known as Mungo Lady at Lake Mungo have been dated to about 40,000–42,000 years ago. The evidence indicates deliberate mortuary behavior (including cremation), showing that complex cultural traditions were present in Sahul by this time.
Mungo Man (Lake Mungo 3), discovered in 1974, is also dated to roughly 40,000–42,000 years ago. The burial, including ochre use, adds to the record of early ceremonial practices and provides a key data point for understanding long-term human presence in southeastern Sahul.
Archaeological research on the Huon Peninsula (Papua New Guinea) reported human occupation at least 40,000 years ago. Because New Guinea and Australia were connected within Sahul during lower sea levels, this supports the idea that early settlers were established across widely separated Sahul regions by the Late Pleistocene.
The lake system in the Willandra Lakes Region stopped functioning as a lake ecosystem around 18,500 years before present. As water sources changed, people would have had to adjust travel routes, campsite locations, and seasonal strategies across inland southeastern Australia.
After the Last Glacial Maximum, rising sea levels flooded low-lying land bridges that had connected Sahul’s regions. This process gradually reduced overland movement between what would become Australia, New Guinea, and Tasmania, changing patterns of contact and exchange.
By roughly 8,000 years ago, rising seas had separated New Guinea from mainland Australia, completing a major step in the breakup of Sahul. This marks a clear endpoint for the initial-colonization era: the first settlers’ descendants were now living on increasingly distinct islands and continents, shaped by new coastlines and sea barriers.
Initial colonization of Sahul (Australia and New Guinea) by Homo sapiens (c. 65–40 ka)