A study by researchers from the University of Adelaide and The Australian National University (ANU) has provided the first genomic evidence of early migration from New Guinea into Wallacea. This region, an archipelago that includes Timor-Leste and hundreds of inhabited eastern Indonesian islands, holds a key position in understanding human history and migration patterns.
Published in the Proceedings of the National Academy of Sciences (PNAS), the study addresses significant gaps in the human genetic history of the Wallacean Archipelago and West Papuan regions of Indonesia. These areas are noted for their abundant genetic and linguistic diversity, which is comparable to that of the entire Eurasian continent.
The research team analyzed 254 newly sequenced genomes. Combined with existing linguistic and archaeological evidence, their findings reveal that Wallacean societies were transformed by the spread of genes and languages from West Papua in the past 3,500 years. This period aligns with the time when Austronesian seafarers were actively interacting and mixing with Wallacean and Papuan groups.
Dr. Gludhug Ariyo Purnomo, the lead author from the University of Adelaide's School of Biological Sciences, commented on the study's implications. "My colleagues at the Indonesian Genome Diversity Project have been studying Indonesia's complex genetic structure for more than a decade," he said. "But this comprehensive study provides confirmation that Papuan ancestry is widespread across Wallacea, pointing to historical migrations from New Guinea."
He continued, "By connecting the dots between genetics, linguistics, and archaeology, we now recognize West Papua as an important bio-cultural hub and the launching place of historical Papuan seafarers that now contribute up to 60% of modern Wallacean ancestry."
"In the era of precision medicine, understanding the genetic structure of human groups is vital for developing treatments that are helpful rather than harmful, with Wallacea and New Guinea having been poorly represented in past genomic surveys," Dr. Purnomo noted.
Associate Professor Ray Tobler from ANU provided further context on the region's history. "Wallacea had been isolated for more than 45,000 years since the arrival of the first human groups," he said. The arrival of Papuan and Austronesian migrants in more recent times reshaped Wallacean culture by introducing new languages. "These new languages diversified and intermingled to create Wallacea's rich linguistic landscape," Professor Tobler explained.
"Our findings suggest that the Papuan and Austronesian migrations were so extensive that they have largely overwritten the ancestry of the first migrants, making the recovery of these ancient migrations from genetic data challenging," he stated.
"There's also been so much movement in Wallacea in the past couple of thousand years, due to the spice trade and slavery, that it obscures the relationship between geography and genetics."
Looking to the future, Professor Tobler emphasized the potential of ancient DNA in uncovering more about the region's past. "What we know about Wallacea and New Guinea is just the tip of the iceberg," he said. "But the use of ancient DNA can help to overcome some of these challenges and help us to understand the origins and legacy of human journeys to the region stretching back tens of thousands of years."
This article was written in collaboration with generative AI company Alchemiq