Genetic research confirms that the first humans arrived in Australia and New Guinea – then part of the supercontinent Sahul – at least 60,000 years ago, using both a southern and a northern migration path. This discovery settles a long-standing debate about the timing and method of this pivotal prehistoric journey.
The Challenge of Sahul’s Isolation
Reaching Sahul (the combined landmass of modern Australia, Tasmania, and New Guinea) required crossing at least 100 kilometers of open ocean, even during glacial periods when sea levels were lower. This makes the arrival of early humans a remarkable feat of seafaring capability. For decades, archaeologists have debated when this occurred: roughly 60,000 years ago (“long chronology”) or around 45,000–50,000 years ago (“short chronology”).
Two Proposed Migration Routes
Two main routes have been proposed. The southern route suggests migration from Southeast Asia through islands like Malaysia, Indonesia, and Timor. The northern route, backed by stronger evidence, proposes that humans traveled via the Philippines and Sulawesi, where million-year-old hominin stone tools have been found.
Genetic Evidence Confirms Both Routes
A study led by Martin Richards at the University of Huddersfield analyzed nearly 2,500 genome sequences from Indigenous Australians, Papua New Guineans, and populations across the western Pacific and Southeast Asia. By tracking DNA mutations and genetic connections, researchers determined that both routes were used, with the northern route being dominant.
“We dated both dispersals to about the same time – roughly 60,000 years ago,” Richards stated, solidifying the “long chronology” and challenging earlier estimates.
Early Exchange Between Islands
The study also revealed that migration wasn’t strictly one-way. An ancient New Guinean genetic lineage was discovered in a 1,700-year-old burial on Sulawesi, indicating early exchange between Sahul and neighboring islands. Soon after settling Sahul, seafaring populations expanded to the Solomon Islands.
Ongoing Debate and New Discoveries
While the genetic evidence is compelling, the field of palaeogenetics continues to evolve rapidly. Recent discoveries, such as 51,200-year-old cave art in Sulawesi and evidence of human activity at the Madjedbebe site in Australia dating back over 60,000 years, reinforce the earlier arrival of humans in Sahul.
The new research adds weight to the growing consensus that the northern route played a crucial role in the initial peopling of Australia. Sophisticated rock art in Sulawesi suggests humans may have been present there as early as 65,000 years ago or more.
In conclusion, the latest genetic data confirms that ancient humans reached Australia and New Guinea at least 60,000 years ago via both southern and northern routes, highlighting their remarkable seafaring skills and the complex patterns of early human migration across Southeast Asia and the Pacific.
