Three Phases of Ancient Migration Shaped the Ancestry of Human Populations in Vanuatu.

The archipelago of Vanuatu has been at the crossroads of human population movements in the Pacific for the past three millennia. To help address several open questions regarding the history of these movements, we generated genome-wide data for 11 ancient individuals from the island of Efate dating from its earliest settlement to the recent past, including five associated with the Chief Roi Mata's Domain World Heritage Area, and analyzed them in conjunction with 34 published ancient individuals from Vanuatu and elsewhere in Oceania, as well as present-day populations. Our results outline three distinct periods of population transformations. First, the four earliest individuals, from the Lapita-period site of Teouma, are concordant with eight previously described Lapita-associated individuals from Vanuatu and Tonga in having almost all of their ancestry from a "First Remote Oceanian" source related to East and Southeast Asians. Second, both the Papuan ancestry predominating in Vanuatu for the past 2,500 years and the smaller component of Papuan ancestry found in Polynesians can be modeled as deriving from a single source most likely originating in New Britain, suggesting that the movement of people carrying this ancestry to Remote Oceania closely followed that of the First Remote Oceanians in time and space. Third, the Chief Roi Mata's Domain individuals descend from a mixture of Vanuatu- and Polynesian-derived ancestry and are related to Polynesian-influenced communities today in central, but not southern, Vanuatu, demonstrating Polynesian genetic input in multiple groups with independent histories.

Karnatukul (Serpent's Glen): A new chronology for the oldest site in Australia's Western Desert.

The re-excavation of Karnatukul (Serpent's Glen) has provided evidence for the human occupation of the Australian Western Desert to before 47,830 cal. BP (modelled median age). This new sequence is 20,000 years older than the previous known age for occupation at this site. Re-excavation of Karnatukul aimed to contextualise the site's painted art assemblage. We report on analyses of assemblages of stone artefacts and pigment art, pigment fragments, anthracology, new radiocarbon dates and detailed sediment analyses. Combined these add significantly to our understanding of this earliest occupation of Australia's Western Desert. The large lithic assemblage of over 25,000 artefacts includes a symmetrical geometric backed artefact dated to 45,570-41,650 cal. BP. The assemblage includes other evidence for hafting technology in its earliest phase of occupation. This research recalibrates the earliest Pleistocene occupation of Australia's desert core and confirms that people remained in this part of the arid zone during the Last Glacial Maximum. Changes in occupation intensity are demonstrated throughout the sequence: at the late Pleistocene/Holocene transition, the mid-Holocene and then during the last millennium. Karnatukul documents intensive site use with a range of occupation activities and different signalling behaviours during the last 1,000 years. This correlation of rock art and occupation evidence refines our understanding of how Western Desert peoples have inscribed their landscapes in the recent past, while the newly described occupation sequence highlights the dynamic adaptive culture of the first Australians, supporting arguments for their rapid very early migration from the coasts and northern tropics throughout the arid interior of the continent.

Temporal variability in shell mound formation at Albatross Bay, northern Australia.

We report the results of 212 radiocarbon determinations from the archaeological excavation of 70 shell mound deposits in the Wathayn region of Albatross Bay, Australia. This is an intensive study of a closely co-located group of mounds within a geographically restricted area in a wider region where many more shell mounds have been reported. Valves from the bivalve Tegillarca granosa (Linnaeus, 1758) were dated. The dates obtained are used to calculate rates of accumulation for the shell mound deposits. These demonstrate highly variable rates of accumulation both within and between mounds. We assess these results in relation to likely mechanisms of shell deposition and show that rates of deposition are affected by time-dependent processes both during the accumulation of shell deposits and during their subsequent deformation. This complicates the interpretation of the rates at which shell mound deposits appear to have accumulated. At Wathayn, there is little temporal or spatial consistency in the rates at which mounds accumulated. Comparisons between the Wathayn results and those obtained from shell deposits elsewhere, both in the wider Albatross Bay region and worldwide, suggest the need for caution when deriving behavioural inferences from shell mound deposition rates, and the need for more comprehensive sampling of individual mounds and groups of mounds.

Genomic insights into the peopling of the Southwest Pacific.

The appearance of people associated with the Lapita culture in the South Pacific around 3,000 years ago marked the beginning of the last major human dispersal to unpopulated lands. However, the relationship of these pioneers to the long-established Papuan people of the New Guinea region is unclear. Here we present genome-wide ancient DNA data from three individuals from Vanuatu (about 3,100-2,700 years before present) and one from Tonga (about 2,700-2,300 years before present), and analyse them with data from 778 present-day East Asians and Oceanians. Today, indigenous people of the South Pacific harbour a mixture of ancestry from Papuans and a population of East Asian origin that no longer exists in unmixed form, but is a match to the ancient individuals. Most analyses have interpreted the minimum of twenty-five per cent Papuan ancestry in the region today as evidence that the first humans to reach Remote Oceania, including Polynesia, were derived from population mixtures near New Guinea, before their further expansion into Remote Oceania. However, our finding that the ancient individuals had little to no Papuan ancestry implies that later human population movements spread Papuan ancestry through the South Pacific after the first peopling of the islands.