The Austronesian language is spread from Madagascar in the west, Island Southeast Asia (ISEA) in the east (e.g. the Philippines and Indonesian archipelagoes) and throughout the Pacific, as far east as Easter Island. While it seems clear that the remote ancestors of Austronesian speakers originated in Southern China, and migrated to Taiwan with the development of rice farming by c. 5500 BP and onto the northern Philippines by c. 4000 BP (the Austronesian Dispersal Hypothesis or ADH), we know very little about the origins and emergence of Austronesian speakers in the Indonesian Archipelago. Using a combination of cranial morphometric and ancient mtDNA analyses on a new dataset from Gua Hairmau, that spans the pre-Neolithic through to Metal Period (5712—5591cal BP to 1864—1719 cal BP), we rigorously test the validity of the ADH in ISEA. A morphometric analysis of 23 adult male crania, using 16 of Martin’s standard measurements, was carried out with results compared to an East and Southeast Asian dataset of 30 sample populations spanning the Late Pleistocene through to Metal Period, in addition to 39 modern samples from East and Southeast Asia, near Oceania and Australia. Further, 20 samples were analyzed for ancient mtDNA and assigned to identified haplogroups. We demonstrate that the archaeological human remains from Gua Harimau cave, Sumatra, Indonesia provide clear evidence for at least two (cranio-morphometrically defined) and perhaps even three (in the context of the ancient mtDNA results) distinct populations from two separate time periods. The results of these analyses provide substantive support for the ADH model in explaining the origins and population history of ISEA peoples.

Maritime migration and island adaptation by anatomically modern humans (AMH) are among the most significant current issues in Southeast Asian archaeology and directly related to their behavioural and technological advancement. In the center of this research hotspot are the Wallacean islands, situated between the Pleistocene landmasses of Sunda and Sahul. Two major migration routes have been suggested for the initial maritime migration from Sunda via Wallacea into Sahul, a northern route into the region of New Guinea and a southern route leading into northern Australia. Here, we report the outcomes of new archaeological research in Central Sulawesi, the most likely entry location for the northern route. Based on our latest findings and new C14 dates from Goa Topogaro 2, we discuss the evidence and timeline for the migration of early modern humans into the Wallacean islands and their adaptation to insular environments during the Late Pleistocene.