In a revelation that challenges recent theories, scientists have discovered that humans arrived in New Guinea and Australia around 60,000 years ago. This finding was made through the analysis of maternal DNA lineages, suggesting that these early travelers used at least two different migration routes through Southeast Asia. This points to sophisticated navigation and maritime skills much earlier than previously believed. The research helps clarify a longstanding mystery about how humans spread across the globe.
An international collaboration between researchers from the University of Huddersfield and the University of Southampton has provided new insights into when and how modern humans, Homo sapiens, first settled in New Guinea and Australia. The project brought together experts in archaeogenetics and maritime archaeology, with funding from the European Research Council awarded to Professor Helen Farr at the University of Southampton. The genetic analysis was led by Professor Martin Richards at the University of Huddersfield.
During the last Ice Age, global sea levels were much lower than they are today. At that time, New Guinea and Australia were joined as a single landmass called Sahul. Scientists have long debated when people arrived on this ancient continent and which routes they used to get there. To address these questions, the researchers combined knowledge from various fields, including genetics, archaeology, earth science, and oceanography. Their goal was to better understand who these early migrants were, where they came from, and when they made the journey.
It has been established that the ancestors of New Guinea inhabitants and Australian Aboriginals lived in Sahul for tens of thousands of years. Many Australian Aboriginals maintain a deep cultural connection to the land that reflects this long history. However, scientists have not always agreed on the exact timing of the first settlement. Two main theories exist: the “long chronology” proposes that humans arrived about 60,000 years ago, while the “short chronology” suggests a later arrival, approximately between 45,000 to 50,000 years ago.
To investigate this debate, the research team analyzed human mitochondrial DNA (mtDNA), which is passed down the maternal line. As mtDNA accumulates changes over generations, it can be used to reconstruct detailed family lineages that trace back into the past. The team studied nearly 2,500 mtDNA genomes from Australian Aboriginals, New Guinea inhabitants, and populations across Southeast Asia and the western Pacific. By constructing a genetic family tree and tracking how lineages spread among regions, they were able to estimate when different groups diverged.
Utilizing the gradual accumulation of genetic changes, known as the “molecular clock,” the researchers dated the oldest lineages found only in Australian Aboriginals and New Guinea inhabitants to around 60,000 years ago. This strongly supports the long chronology model. The genetic evidence also revealed where these initial populations came from. The oldest lineages trace back to Southeast Asia, but not from a single location. Most lineages point to northern areas, such as northern Indonesia and the Philippines. At the same time, a notable portion originates from southern regions, including southern Indonesia, Malaysia, and Indochina. This pattern suggests that early humans likely entered Sahul via at least two separate migration routes, both occurring around the same time.
These findings are significant because they align well with archaeological and environmental evidence. In recent years, some genetic studies have begun to favor a more recent arrival, but this new analysis provides strong support for an older timeline. Professor Richards stated: “We feel this is a strong support for the long chronology. Still, estimates based on the molecular clock can always be challenged, and mitochondrial DNA is just one line of descent. We are currently analyzing hundreds of complete human genome sequences—3 billion bases each, compared to 16,000—to test our results against the many thousands of other lineages across the human genome. In the future, there will be more archaeological discoveries, and we can also expect ancient DNA to be recovered from key remains, so we can test these models more directly and distinguish between them.” Professor Farr added: “This is a big story that helps refine our understanding of human origins, maritime mobility, and early navigation narratives. It reflects the truly deep heritage that Indigenous communities have in this region and the skills and technology of these early travelers.”
Understanding the chronology and migration routes of the first humans to reach Australia and New Guinea is essential to the history of human occupation in the region. The research not only illuminates the past but also helps contextualize the cultural practices and ancestral links that persist today in Indigenous communities. Mitochondrial DNA analysis is a valuable tool, but not the only line of evidence. The ongoing study of complete genomes and future archaeological discoveries promise to further deepen the understanding of these ancient migrations. The use of advanced technologies in genetic analysis and interdisciplinary collaboration are key to unraveling the complex migration patterns that have shaped human history. The research highlights the importance of integrating genetic, archaeological, and environmental data to form a comprehensive picture of early human journeys. While the debate over the exact chronology continues, the evidence points to a human presence in Sahul dating back 60,000 years, challenging previous assumptions and reinforcing the importance of Indigenous contributions to global history.
Original published at O Cafezinho.