A major new genomic study has reignited the debate over when humans first reached the ancient supercontinent of Sahul, present-day Australia, New Guinea, and Tasmania, concluding that the earliest settlers arrived around 60,000 to 65,000 years ago, far earlier than some previous genetic estimates suggested.
The research, published in Science Advances, analyzed an unprecedented dataset of 2,456 mitochondrial genomes from Indigenous populations across Australia, New Guinea, Island Southeast Asia, and Oceania. By combining this vast genetic record with Y-chromosome data, archaeological evidence, climatological modeling, and updated mutation-rate estimates, the researchers argue decisively for what has long been called the “long chronology” of human migration into Sahul.
For decades, archaeological sites such as Madjedbebe in northern Australia, dated to nearly 65,000 years old, indicated a very early human presence. But some genomic studies produced younger estimates, suggesting arrival between 47,000 and 51,000 years ago. The new findings reconcile these differences, bringing genetic timelines into alignment with the oldest archaeological evidence.
One of the study’s most striking conclusions is that early humans did not enter Sahul through a single corridor. Instead, the genomic patterns show evidence for at least two distinct migration routes: northern and southern. The northern route is believed to have traveled through island-based Southeast Asia, into New Guinea. The southern route was likely through mainland Southeast Asia and into northern Australia, the study said.
The researchers found that different ancient mitochondrial lineages, both dating back roughly 60,000 years, are distributed across distinct regions of Sahul. This, they say, is best explained by multiple simultaneous settlement pathways rather than a single dispersal event.
The human journey to 'Sahul'
Reaching Sahul required open-water voyages across the Wallace Line: a deep-water barrier separating Asian and Australian ecosystems. The findings strengthen the view that early humans possessed sophisticated maritime skills far earlier than once believed.
“This helps refine our understanding of human origins, maritime mobility, and early seafaring narratives,” one of the study’s authors said in an accompanying university statement. “It reflects the deep heritage that Indigenous communities have in this region and the skills and technology of these early voyagers.”
The study affirms that the ancestors of present-day Indigenous Australians and Papuans represent one of the world’s most ancient continuous human populations outside Africa. Their genetic lineages have remained isolated for tens of thousands of years, providing rare insight into some of the earliest chapters of human migration.
By integrating genomic evidence with archaeological and environmental data at an unprecedented scale, the study marks a significant shift in understanding the human journey across the globe.
“Our findings support the view that humans left Africa earlier than previously thought and reached the Sunda region by around 60,000 years ago,” the authors wrote. “Settlement of Sahul followed rapidly, likely through multiple routes.”
The study not only bolsters long-standing archaeological claims but reshapes the broader story of early human expansion, showing that the first Australians were among the most skilled navigators and explorers of the ancient world.