The Arrival of the First Humans in Australia: A Genomics Study
Approximately 60,000 years ago, the first humans set foot on the landmass that we now know as Australia, following two distinct routes, as revealed by a recent genomics study.
The debate among archaeologists regarding the timing of human arrival on the continent has been ongoing. Some have previously suggested dates around 45 to 50,000 years ago based on genetic evidence, while others propose an earlier settlement, possibly as far back as 65,000 years ago.
This new study, which analyzed nearly 2,500 sets of mitochondrial DNA from indigenous populations of Australia, New Guinea, Oceania, and Southeast Asia, supports the notion of an earlier arrival date and unveils the fact that it was not a single migration event.
Two Routes to Sahul
The landmass of Sahul, comprising what is now Australia, Tasmania, and New Guinea, was connected during the Pleistocene epoch until approximately 9,000 years ago when rising sea levels marked the end of the last ice age.
Archaeogeneticist Martin Richards and his team from the University of Huddersfield in the UK examined DNA mutation rates and genetic connections among modern and ancient human populations to trace the remarkable journey undertaken so early in human history.
It appears that humans took two distinct routes from the ancient landmass of Sunda to reach Sahul. Some traveled through Malaysia, Java, and Timor, entering Sahul west of present-day Darwin, known as the ‘southern route lineages’. Meanwhile, the ‘northern route lineages’ followed a separate path through the island chain from the Philippines and Sulawesi to Papua New Guinea, reaching Sahul via the northern tip of modern Queensland.
“Both migrations are estimated to have occurred around 60,000 years ago,” Richards explained. This finding supports the idea of an earlier settlement, contrary to the ‘short chronology’ proposing a later arrival between 45,000 to 50,000 years ago.
The study suggests that 36 percent of the initial lineages can be traced back to those who arrived via the northern route, with the remaining 64 percent descending from ancestors who took the southern path.
Furthermore, some of the earliest migrants on the northern route continued their journey to the Bismarck Archipelago and the Solomon Islands shortly after reaching Sahul.
Considering their legacy, the authors noted that “most of the surviving lineages in ancient Sahul and Near Oceania are derived from ancestors who arrived via the northern route around 60,000 years ago, with a minority arriving via the southern route through southern Sunda.”
The absence of ancient DNA from southern Asia and Sahul limits further insights into the timing of these genetic events, underscoring the need for more research in this area.
The findings of this study were published in Science Advances, shedding light on the intricate journey of the first humans to populate the vast and diverse continent of Australia.
