Origins of Polynesian Pigs Revealed by Mitochondrial Whole Genome Ancient DNA.

Domestic pigs (Sus scrofa) were first transported to Polynesia through a series of long-distance voyages ultimately linked to the Neolithic expansion of Austronesian-speaking people out of Asia. The descendants of the founding pigs belong to a rare mtDNA group referred to as the "Pacific Clade" that may have originated in peninsular or island Southeast Asia. We report the first whole genome mtDNA from domestic pigs from any of the remote islands of the Pacific. In this brief report, we describe the close link we discovered between ancient mtDNA from archaeological specimens from across Polynesia and from that of modern pigs in northern peninsular Southeast Asia, specifically southern China's Yunnan Province. More complete mtDNA coverage in commensal animals is necessary to improve our picture of the settlement of Polynesia (ca. 2800-700 years before the present) and specify the route, or routes, that pigs took from northern peninsular Southeast Asia.

The importance of shell: Redating of the To'aga site (Ofu Island, Manu'a) and a revised chronology for the Lapita to Polynesian Plainware transition in Tonga and Samoa.

Radiocarbon dating Pacific archaeological sites is fraught with difficulties. Often situated in coastal beach ridges or sand dunes, these sites exhibit horizontal and vertical disturbances, datable materials such as wood charcoal are typically highly degraded, may be derived from old trees or driftwood unless specifically identified to short-lived material, while bone collagen rarely survives in tropical conditions. Shell, therefore, is the most logical material for dating Pacific sites since it is resistant to alteration, can be sampled to ensure only the last few seasons of growth are represented and is often closely tied to human economic activities. However, shell radiocarbon (14C) dating has been plagued by interpretive problems largely due to our limited knowledge of the 14C cycle in nearshore marine and estuarine environments. Consequently, shell dates are typically ignored in regional chronometric evaluations and in recent years shell is often avoided for dating altogether. Recent advances in our understanding of the source of shell 14C as well as the development of the first South Pacific Gyre model of changing marine 14C over time, combined with Bayesian statistical modelling, now provide us with insight into the value of these shell radiocarbon dates. Here we present a revision of the age of the To'aga site on Ofu Island-an early occupation site associated with the initial Polynesian Plainware period in Samoa, the earliest use of which we date to between 2785 and 2607 cal BP (68% probability).

Correction: Investigating the Global Dispersal of Chickens in Prehistory Using Ancient Mitochondrial DNA Signatures.

[This corrects the article DOI: 10.1371/journal.pone.0039171.].

Restructuring of nutrient flows in island ecosystems following human colonization evidenced by isotopic analysis of commensal rats.

The role of humans in shaping local ecosystems is an increasing focus of archaeological research, yet researchers often lack an appropriate means of measuring past anthropogenic effects on local food webs and nutrient cycling. Stable isotope analysis of commensal animals provides an effective proxy for local human environments because these species are closely associated with human activities without being under direct human management. Such species are thus central to nutrient flows across a range of socionatural environments and can provide insight into how they intersected and transformed over time. Here we measure and compare stable carbon and nitrogen isotope data from Pacific rat (Rattus exulans) skeletal remains across three Polynesian island systems [Mangareva, Ua Huka (Marquesas), and the Polynesian Outlier of Tikopia] during one of the most significant cases of human migration and commensal introduction in prehistory. The results demonstrate widespread δ15N declines across these islands that are associated with human land use, intensification, and faunal community restructuring. Local comparison of rat stable isotope data also tracks human activities and resource availability at the level of the settlement. Our results highlight the large-scale restructuring of nutrient flows in island ecosystems that resulted from human colonization and ecosystem engineering activities on Pacific islands. They also demonstrate that stable isotope analysis of often-ignored commensal taxa can provide a tool for tracking human land use and environmental effects.

Cook Island artifact geochemistry demonstrates spatial and temporal extent of pre-European interarchipelago voyaging in East Polynesia.

The Cook Islands are considered the "gateway" for human colonization of East Polynesia, the final chapter of Oceanic settlement and the last major region occupied on Earth. Indeed, East Polynesia witnessed the culmination of the greatest maritime migration in human history. Perennial debates have critiqued whether Oceanic settlement was purposeful or accidental, the timing and pathways of colonization, and the nature and extent of postcolonization voyaging-essential for small founding groups securing a lifeline between parent and daughter communities. Centering on the well-dated Tangatatau rockshelter, Mangaia, Southern Cook Islands, we charted the temporal duration and geographic spread of exotic stone adze materials-essential woodworking tools found throughout Polynesia- imported for more than 300 y beginning in the early AD 1300s. Using a technique requiring only 200 mg of sample for the geochemical analysis of trace elements and isotopes of fine-grained basalt adzes, we assigned all artifacts to an island or archipelago of origin. Adze material was identified from the chiefly complex on the Austral Islands, from the major adze quarry complex on Tutuila (Samoa), and from the Marquesas Islands more than 2,400 km distant. This interaction is the only dated example of down-the-line exchange in central East Polynesia where intermediate groups transferred commodities attesting to the interconnectedness and complexity of social relations fostered during postsettlement voyaging. For the Cook Islands, this exchange may have lasted into the 1600s, at least a century later than other East Polynesian archipelagos, suggesting that interarchipelago interaction contributed to the later development of social hierarchies.

Investigating the global dispersal of chickens in prehistory using ancient mitochondrial DNA signatures.

Data from morphology, linguistics, history, and archaeology have all been used to trace the dispersal of chickens from Asian domestication centers to their current global distribution. Each provides a unique perspective which can aid in the reconstruction of prehistory. This study expands on previous investigations by adding a temporal component from ancient DNA and, in some cases, direct dating of bones of individual chickens from a variety of sites in Europe, the Pacific, and the Americas. The results from the ancient DNA analyses of forty-eight archaeologically derived chicken bones provide support for archaeological hypotheses about the prehistoric human transport of chickens. Haplogroup E mtDNA signatures have been amplified from directly dated samples originating in Europe at 1000 B.P. and in the Pacific at 3000 B.P. indicating multiple prehistoric dispersals from a single Asian centre. These two dispersal pathways converged in the Americas where chickens were introduced both by Polynesians and later by Europeans. The results of this study also highlight the inappropriate application of the small stretch of D-loop, traditionally amplified for use in phylogenetic studies, to understanding discrete episodes of chicken translocation in the past. The results of this study lead to the proposal of four hypotheses which will require further scrutiny and rigorous future testing.

Interpolity exchange of basalt tools facilitated via elite control in Hawaiian archaic states.

Ethnohistoric accounts of late precontact Hawaiian archaic states emphasize the independence of chiefly controlled territories (ahupua'a) based on an agricultural, staple economy. However, elite control of unevenly distributed resources, such as high-quality volcanic rock for adze production, may have provided an alternative source of economic power. To test this hypothesis we used nondestructive energy-dispersive X-ray fluorescence (ED-XRF) analysis of 328 lithic artifacts from 36 archaeological features in the Kahikinui district, Maui Island, to geochemically characterize the source groups. This process was followed by a limited sampling using destructive wavelength-dispersive X-ray fluorescence (WD-XRF) analysis to more precisely characterize certain nonlocal source groups. Seventeen geochemical groups were defined, eight of which represent extra-Maui Island sources. Although the majority of stone tools were derived from Maui Island sources (71%), a significant quantity (27%) of tools derived from extraisland sources, including the large Mauna Kea quarry on Hawai'i Island as well as quarries on O'ahu, Moloka'i, and Lana'i islands. Importantly, tools quarried from extralocal sources are found in the highest frequency in elite residential features and in ritual contexts. These results suggest a significant role for a wealth economy based on the control and distribution of nonagricultural goods and resources during the rise of the Hawaiian archaic states.

Household expansion linked to agricultural intensification during emergence of Hawaiian archaic states.

The Leeward Kohala Field System (LKFS) covering ∼ 60 km(2) on Hawai'i Island is one of the world's best-studied archaeological examples of preindustrial agricultural intensification. Archaeological correlates for households over a 400-y period of intensification of the LKFS (A.D. 1400-1800) indicate that household age, number, and distribution closely match the expansion of agricultural features at both macro- and microscales. We excavated and dated residential complexes within portions of five traditional Hawaiian land units (ahupua'a), two in the central core of the field system and three in the southern margins. Forty-eight radiocarbon dates from 43 residential features indicate an overall pattern of exponential increase in the numbers of households over time. Spatial distribution of these dates suggests that the core of the LKFS may have reached a population saturation point earlier than in the southern margins. Bayesian statistical analysis of radiocarbon dates from residential features in the core region, combined with spatial analysis of agricultural and residential construction sequences, demonstrates that the progressive subdivision of territories into smaller socioeconomic units was matched by addition of new residences, probably through a process of household fissioning. These results provide insights into the economic processes underlying the sociopolitical transformation from chiefdom to archaic state in precontact Hawai'i.

Rapid evolution of ritual architecture in central Polynesia indicated by precise 230Th/U coral dating.

In Polynesia, the complex Society Islands chiefdoms constructed elaborate temples (marae), some of which reached monumental proportions and were associated with human sacrifice in the 'Oro cult. We investigated the development of temples on Mo'orea Island by 230Th/U dating of corals used as architectural elements (facing veneers, cut-and-dressed blocks, and offerings). The three largest coastal marae (associated with the highest-ranked chiefly lineages) and 19 marae in the inland 'Opunohu Valley containing coral architectural elements were dated. Fifteen corals from the coastal temples meet geochemical criteria for accurate 230Th/U dating, yield reproducible ages for each marae, and have a mean uncertainty of 9 y (2sigma). Of 41 corals from wetter inland sites, 12 show some diagenesis and may yield unreliable ages; however, the majority (32) of inland dates are considered accurate. We also obtained six 14C dates on charcoal from four marae. The dates indicate that temple architecture on Mo'orea Island developed rapidly over a period of approximately 140 y (ca. AD 1620-1760), with the largest coastal temples constructed immediately before initial European contact (AD 1767). The result of a seriation of architectural features corresponds closely with this chronology. Acropora coral veneers were superceded by cut-and-dressed Porites coral blocks on altar platforms, followed by development of multitier stepped altar platforms and use of pecked basalt stones associated with the late 'Oro cult. This example demonstrates that elaboration of ritual architecture in complex societies may be surprisingly rapid.

Coral 230Th dating of the imposition of a ritual control hierarchy in precontact Hawaii.

In proto-historic Hawaii (1500-1795 A.D.), as in many other evolving polities, temples functioned as centers for control over production and the extraction of surplus food and goods. Thorium-230 dates (uncertainty +/- approximately 10 years) on branch coral dedicatory offerings from temples in the Kahikinui district (Maui) indicate that its temple system was constructed within 60 years, far more rapidly than indicated by radiocarbon dating. Introduction of the temple system in 1580-1640 A.D. coincided with predatory expansion and consolidation of the Maui polity to form an incipient archaic state.