Geoffrey Clark

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.

A 3000-Year Culture Sequence from Palau, Western Micronesia

In western Micronesia archaeological sites containing material-culture remains spanning millennia are rare. This paper reports one from Ulong Island in Palau, which is radiocarbon dated to 3000 cal. B.P. The pottery sequence was divided into three assemblages, each distinguished by distinct vessel forms and by the type and proportion of nonplastic temper inclusions. An abrupt transformation of the ceramic assemblage is tentatively dated to around 2400 cal. B.P., coincident with substantial landscape alteration on the main island where pottery was manufactured, indicating that anthropogenic activity may have constrained the raw materials available to prehistoric potters. There is a discontinuity in the sequence from 2000-1000 B.P. that might represent an hiatus in site use. Critical consideration of paleoenvironmental data pointing to human arrival at 4500-4300 cal. B.P. suggests, instead, that climatic events may be responsible for the observed palaeoecological changes. If so, then sites dating to 3300-3000 cal. B.P., such as Ulong, could well be among the oldest in western Micronesia.

Human Colonization of the Palau Islands, Western Micronesia

ABSTRACT Adaptation to new environments is an important issue in colonization research with implications for accurately establishing the timing of human arrival and interpreting the dispersal pattern from the distribution of early archaeological sites. Island groups frequently contain a diverse range of landscapes and geographic variation in their colonization records that might reflect the environmental preference of prehistoric migrants. In the Palau Islands the large island of Babeldaob may have been colonized by 4300 cal BP on palaeoenvironmental evidence, while the oldest archaeological deposits in the small limestone islands of southern Palau date to ∼ca. 3000 cal BP. Does the discrepancy in colonization ages represent a predilection for the large volcanic island relative to small limestone islands? To examine the timing of human arrival in southern Palau an early site on Ulong Island was re-excavated, along with ancillary investigations to calculate a local reservoir value (ΔR) to apply to new marine shell 14C ages and investigation of a buried sea-notch to estimate the impact of sea-level change and tectonic movement. Human arrival in southern Palau is dated to no earlier than 3100–2900 cal BP. Neolithic dispersal in other island environments in the Pacific is reviewed to see whether colonization of large islands tended to precede use of small islands. The general pattern is for the oldest sites to be located on large islands, with human activity archaeologically visible throughout an archipelago within 100–300 years. A similar interval applied to Palau would put colonization at 3400–3100 cal BP, but this needs to be confirmed by palaeoenvironmental and archaeological investigations in coastal Babeldaob.

Monumentality and the development of the Tongan maritime chiefdom

On Tongatapu the central place of the rising kingdom of Tonga developed in the fourteenth and fifteenth centuries AD. Marked out as a monumental area with a rock-cut water-carrying ditch, it soon developed as the site of a sequence of megalithic tombs, in parallel with the documented expansion of the maritime chiefdom. The results of investigations into these structures were achieved with minimum intervention and disturbance on the ground, since the place remains sacred and in use

Comparative Radiocarbon Dating of Lignite, Pottery, and Charcoal Samples from Babeldaob Island, Republic of Palau

It is difficult to construct archaeological chronologies for Babeldaob, the main island of Palau (western Micronesia), because the saprolitic clays of the dominant terraced-hill sites and associated ceramic sherds often contain old carbon that originated in lignites. This has implications, as well, for chronologies of sedimentary sequences. Comparative analysis of the dating problem using lignite, pottery, and charcoal samples indicates that, in fact, there are both old and young sources of potential contamination. It is concluded that radiocarbon samples from Babeldaob need to be tested for appropriate carbon content rather than relying solely upon material identification.

Faunal and floral remains from Earnscleugh Cave, Central Otago, New Zealand

Earnscleugh Cave, near Alexandra in Central Otago, was excavated in order to recover and date faunal and floral remains and to provide a palaeoenvironmental analysis. The pollen analysis showed that a complex vegetation community, comprising a dense scrub with local stands of podcarps, grew around the cave during the late Holocene and before Polynesian deforestation. The results from Earnscleugh Cave suggest that at this time permanent water‐courses on the flanks of Central Otago ranges supported diverse and rich plant communities of forest and shrubland. The cave fauna included moas Euiyapteryx geranoides. Emeus crassus and Dinornis giganteus, goose Cnemiornis calcitrans, Finschs duck Euryanas finschi, kea Nestor notabilis, rifleman Acanthisitta chloris, robin Petroica austrailis, tuatara Sphenodon sp. and greater short‐tailed bat Mystacina cf. robusta.

Stone tools from the ancient Tongan state reveal prehistoric interaction centers in the Central Pacific

Significance The Tongan state was the only maritime polity in Oceania to encompass an entire archipelago and, through long-distance voyaging, to extend its influence to other island groups through political and economic exchanges. Stone tools recovered from the central places of the Tongan state were geochemically analyzed to provide the first archaeological assessment of maritime interaction in the Central Pacific, with a high proportion of tools (66%) identified as long-distance imports from Fiji, Samoa, and the Society Islands. Exotic lithics were an important source of political capital used by Tongan elites, and an important consequence of centralization was the development of interaction centers through which people, products, and information about political organizations reached many parts of the prehistoric Pacific. Tonga was unique in the prehistoric Pacific for developing a maritime state that integrated the archipelago under a centralized authority and for undertaking long-distance economic and political exchanges in the second millennium A.D. To establish the extent of Tonga’s maritime polity, we geochemically analyzed stone tools excavated from the central places of the ruling paramounts, particularly lithic artifacts associated with stone-faced chiefly tombs. The lithic networks of the Tongan state focused on Samoa and Fiji, with one adze sourced to the Society Islands 2,500 km from Tongatapu. To test the hypothesis that nonlocal lithics were especially valued by Tongan elites and were an important source of political capital, we analyzed prestate lithics from Tongatapu and stone artifacts from Samoa. In the Tongan state, 66% of worked stone tools were long-distance imports, indicating that interarchipelago connections intensified with the development of the Tongan polity after A.D. 1200. In contrast, stone tools found in Samoa were from local sources, including tools associated with a monumental structure contemporary with the Tongan state. Network analysis of lithics entering the Tongan state and of the distribution of Samoan adzes in the Pacific identified a centralized polity and the products of specialized lithic workshops, respectively. These results indicate that a significant consequence of social complexity was the establishment of new types of specialized sites in distant geographic areas. Specialized sites were loci of long-distance interaction and formed important centers for the transmission of information, people, and materials in prehistoric Oceania.

Ceramic petrography and cultural interaction in Palau, Micronesia

Because of their durability and widespread use, ceramics in the Pacific are important artifacts for examining patterns of prehistoric subsistence, settlement, and societal interaction. Numerous studies demonstrate that petrographic analysis of prehistoric pottery in western Oceania can differentiate temper sands and other mineral constituents unique to geotectonically different islands. However, a detailed study of tempering agents has not been attempted for ceramic assemblages in Palau, Western Caroline Islands, Micronesia. We present the first major synthesis of Palauan ceramic petrography and petrological classification. The analysis of several sherd suites recovered from both the volcanic and limestone islands in the archipelago and other nearby western Micronesian atolls suggest that pottery was locally made, manufactured using primarily grog or composite (mixed-grog sand) tempers, and transported to smaller islands within and outside of the Palauan archipelago. The research has implications for determining raw material acquisition by ancient Palauan potters and is a critical step for developing regional models of intra- and inter-island exchange and interaction.

A Marine Reservoir Correction Value (ΔR) for the Palauan Archipelago: Environmental and Oceanographic Considerations

ABSTRACT This paper investigates the marine reservoir effect (ΔR) around Palau with specific focus on environmental and oceanographic causes of variation. Two new ΔR values of known-age, pre-AD 1950 Scaridae sp. fish bone from the lagoon, are compared to extant marine shell values from the western branch of the North Pacific Gyre. This review indicates that a ΔR value of 75 ± 68 14C yrs for the ocean immediately surrounding Palau best fits the available evidence, while a value of −52 ± 22 14C yrs should be used for the southwest lagoon. Comparison of marine and charcoal samples from archaeological deposits on Ulong Island lend support to this regional open ocean marine reservoir value, but additional analysis is required to assess the stability of this value around the archipelago and over time. The analysis highlights that careful, informed selection of radiocarbon samples is essential to produce tight radiocarbon chronologies for Pacific archaeological sites.

Obsidian Source Use in Tongan Prehistory: New Results and Implications

ABSTRACT The article presents results of an obsidian sourcing study on artifacts from Tonga and Fiji. New LA-ICPMS data on obsidian source locations on Tafahi in northern Tonga are discussed in relation to inter-island mobility during two important phases in the Central Pacific: the late-Lapita phase in Fiji-West Polynesia at 2700–2600 cal. BP and during the time of the rise of Polynesian chiefdoms at ∼1000–400 cal. BP. The sourcing results indicate that two sources of obsidian were exploited during Tongan prehistory. It is suggested that different modes of interaction were responsible for obsidian movement during the early and late phases of Tongan prehistory.