Scientists have discovered when and by what routes people first settled Australia and New Guinea

Recent research shows that humans first reached Sahul (Australia and New Guinea) around 60,000 years ago, following two primary migration routes from Southeast Asia. This supports the “long chronology” of settlement and challenges earlier ideas that later migrations displaced the first inhabitants.

A collaboration between the Archaeogenetics Research Group at the University of Huddersfield and the Centre for Maritime Archaeology at the University of Southampton has provided new insights into the first human settlement of New Guinea and Australia, improving our understanding of early seafaring and maritime movement.

During the last ice age, New Guinea and Australia formed a single landmass called Sahul. While Homo sapiens evolved in Africa, the timing and routes of their arrival in Sahul have been debated. New research, published in Science Advances, combined genetics, archaeology, earth science, and oceanography to investigate when, where, and how these early migrations occurred.

The study focused on mitochondrial DNA (mtDNA), inherited maternally, to reconstruct detailed maternal lineages. Analysis of nearly 2,500 mtDNA genomes from Aboriginal Australians, New Guineans, and Western Pacific and Southeast Asian populations showed that the oldest unique lineages date back about 60,000 years, supporting the “long chronology” of settlement. Most originated in northern Southeast Asia (northern Indonesia and the Philippines), while some came from southern regions (southern Indonesia, Malaysia, and Indochina), indicating at least two migration routes. Northern route lineages spread throughout New Guinea and Australia, whereas southern route lineages were mostly limited to southern Australia.

These findings were further validated using Y-chromosome and whole-genome data, alongside archaeological, paleogeographical, and environmental evidence. Although ancient DNA from tropical regions is scarce, one Indonesian Iron Age sample showed later “back” migrations from New Guinea, but it did not inform the initial settlement.

The results confirm that modern Aboriginal Australians and New Guineans descend from the first settlers who arrived around 60,000 years ago, rather than being replaced by later migration waves. Molecular clock analysis of the DNA lineages, calibrated using known settlement dates from remote Pacific islands, provided robust timing for these migrations and demonstrated continuity between the earliest settlers and present populations.