Humans arrived in Australia at least 65,000 years ago, part of an early wave traveling east from Africa through Eurasia. However, new research published in Nature Communications suggests that a significant wave of migration reached the island of Timor not long after 50,000 years ago, indicating a complex pattern of human colonization driven by climate change and adaptability.
Timor has been considered a potential stepping-stone between mainland Southeast Asia and Australia/New Guinea. During ancient migrations, lower sea levels connected many islands in Southeast Asia (Sunda) and Australia/New Guinea (Sahul). However, the islands in Wallacaea, including Timor, remained isolated due to deep sea channels.
Research at Laili rock shelter in central-north Timor-Leste uncovered sediments dating from 59,000 to 54,000 years ago devoid of human presence. Evidence of human activity was found in layers dating back to about 44,000 years ago, indicating a significant arrival of humans around this time. This supports the idea that humans only reached this region between 47,000 and 45,000 years ago.
Sediment analysis using micromorphology at Laili revealed abrupt signs of human occupation, such as hearths, stone artifacts, and dietary remains rich in fish and shellfish. This suggests a deliberate and large-scale colonization effort rather than an ad-hoc settlement by a small population.
The findings challenge previous theories, suggesting that the initial human migration into Sahul likely occurred via New Guinea rather than Timor. This path, while less direct, may have been chosen due to the greater availability of land-dwelling animals in northern islands, as opposed to the southern islands like Timor, which required a diet more reliant on fish and shellfish.
This new evidence indicates that human migration to the southern islands was an ongoing process, rather than a single event, occurring thousands of years after the initial settlement of Australia. This later wave of migration might have been significant enough to overshadow earlier, smaller migrations via different routes.
The research prompts a reevaluation of the route and timing of the earliest human migration into Sahul, suggesting a complex and multi-phased colonization history influenced by environmental factors and resource availability.
