New genomic research confirms that the first humans reached Australia and surrounding landmasses approximately 60,000 years ago, not through a single migration, but via two separate routes. This discovery resolves long-standing debate among archaeologists regarding the timing and pathways of early human settlement in the region.
The Contested History of Australian Settlement
The question of when humans first populated Australia has been debated for decades. Previous genetic studies suggested arrival dates ranging from 45,000 to 65,000 years ago. The new findings, based on the analysis of nearly 2,500 mitochondrial DNA samples from Indigenous populations across Australia, New Guinea, Oceania, and Southeast Asia, strengthens the evidence for an earlier settlement date while revealing the complexity of the migrations.
Sahul: The Ancient Supercontinent
To understand the migrations, it’s crucial to know that Australia, Tasmania, and New Guinea were once connected as a single landmass known as Sahul during the Pleistocene epoch. This supercontinent was separated from mainland Asia by rising sea levels around 9,000 years ago. The new research clarifies how humans navigated this landscape even earlier, at a time when sea levels were lower.
Two Migration Pathways: North and South
The study, led by archaeogeneticist Martin Richards, traced genetic connections between modern and ancient populations alongside archaeological and climatic data. The findings indicate two distinct routes from the ancient landmass of Sunda (present-day Southeast Asia) to Sahul.
- The Southern Route: Migrants traveled through Malaysia, Java, and Timor, landing in Sahul west of Darwin. Approximately 64% of the first-wave lineages descend from these early pioneers.
- The Northern Route: A separate group moved along the island chain from the Philippines and Sulawesi to Papua New Guinea, eventually reaching Sahul via northern Queensland. Roughly 36% of the first-wave lineages are linked to this migration path.
Genetic Legacy and Further Exploration
Researchers estimate that while the northern route contributed significantly to the genetic makeup of Sahul’s early populations, the southern route was dominant, particularly in Australia, where two-thirds of the lineages descend from this pathway. Some of the earliest northern migrants also continued onward to the Bismarck Archipelago and Solomon Islands shortly after landing in Sahul.
The research also highlights a critical gap in current knowledge: a lack of ancient DNA from southern Asia and Sahul. This missing data could provide a more precise timeline of these genetic events and deepen our understanding of the earliest human migrations in the region.
In conclusion, this study provides strong genomic evidence for a more complex and earlier history of Australian settlement than previously understood. The dual migration routes challenge earlier assumptions and underscore the remarkable adaptability of early humans in navigating vast distances and settling new lands.
