Atholl Anderson

Dating the late prehistoric dispersal of Polynesians to New Zealand using the commensal Pacific rat

The pristine island ecosystems of East Polynesia were among the last places on Earth settled by prehistoric people, and their colonization triggered a devastating transformation. Overhunting contributed to widespread faunal extinctions and the decline of marine megafauna, fires destroyed lowland forests, and the introduction of the omnivorous Pacific rat (Rattus exulans) led to a new wave of predation on the biota. East Polynesian islands preserve exceptionally detailed records of the initial prehistoric impacts on highly vulnerable ecosystems, but nearly all such studies are clouded by persistent controversies over the timing of initial human colonization, which has resulted in proposed settlement chronologies varying from ≈200 B.C. to 1000 A.D. or younger. Such differences underpin radically divergent interpretations of human dispersal from West Polynesia and of ecological and social transformation in East Polynesia and ultimately obfuscate the timing and patterns of this process. Using New Zealand as an example, we provide a reliable approach for accurately dating initial human colonization on Pacific islands by radiocarbon dating the arrival of the Pacific rat. Radiocarbon dates on distinctive rat-gnawed seeds and rat bones show that the Pacific rat was introduced to both main islands of New Zealand ≈1280 A.D., a millennium later than previously assumed. This matches with the earliest-dated archaeological sites, human-induced faunal extinctions, and deforestation, implying there was no long period of invisibility in either the archaeological or palaeoecological records.

High-precision radiocarbon dating shows recent and rapid initial human colonization of East Polynesia.

The 15 archipelagos of East Polynesia, including New Zealand, Hawaii, and Rapa Nui, were the last habitable places on earth colonized by prehistoric humans. The timing and pattern of this colonization event has been poorly resolved, with chronologies varying by >1000 y, precluding understanding of cultural change and ecological impacts on these pristine ecosystems. In a meta-analysis of 1,434 radiocarbon dates from the region, reliable short-lived samples reveal that the colonization of East Polynesia occurred in two distinct phases: earliest in the Society Islands A.D. ∼1025–1120, four centuries later than previously assumed; then after 70–265 y, dispersal continued in one major pulse to all remaining islands A.D. ∼1190–1290. We show that previously supported longer chronologies have relied upon radiocarbon-dated materials with large sources of error, making them unsuitable for precise dating of recent events. Our empirically based and dramatically shortened chronology for the colonization of East Polynesia resolves longstanding paradoxes and offers a robust explanation for the remarkable uniformity of East Polynesian culture, human biology, and language. Models of human colonization, ecological change and historical linguistics for the region now require substantial revision.

The chronology of colonization in New Zealand

New Zealand was the last substantial landmass to be colonized by prehistoric people. Even within Oceania, where there are much smaller and more remote islands, such as Pitcairn and Easter Island, New Zealand stands out as the last-settled archipelago. Its prehistory promises, therefore, better archaeological evidence concerning prehistoric colonization of pristine land-masses than is the case anywhere else, as is apparent in the extinction of megafauna (Anderson 1989a). But much depends on the precise antiquity of human colonization and this, following a long period of consensus, is now a matter of sharp debate.

Phylogeny and ancient DNA of Sus provides insights into neolithic expansion in Island Southeast Asia and Oceania

Human settlement of Oceania marked the culmination of a global colonization process that began when humans first left Africa at least 90,000 years ago. The precise origins and dispersal routes of the Austronesian peoples and the associated Lapita culture remain contentious, and numerous disparate models of dispersal (based primarily on linguistic, genetic, and archeological data) have been proposed. Here, through the use of mtDNA from 781 modern and ancient Sus specimens, we provide evidence for an early human-mediated translocation of the Sulawesi warty pig (Sus celebensis) to Flores and Timor and two later separate human-mediated dispersals of domestic pig (Sus scrofa) through Island Southeast Asia into Oceania. Of the later dispersal routes, one is unequivocally associated with the Neolithic (Lapita) and later Polynesian migrations and links modern and archeological Javan, Sumatran, Wallacean, and Oceanic pigs with mainland Southeast Asian S. scrofa. Archeological and genetic evidence shows these pigs were certainly introduced to islands east of the Wallace Line, including New Guinea, and that so-called “wild” pigs within this region are most likely feral descendants of domestic pigs introduced by early agriculturalists. The other later pig dispersal links mainland East Asian pigs to western Micronesia, Taiwan, and the Philippines. These results provide important data with which to test current models for human dispersal in the region.

Late colonization of East Polynesia

In a recent A NTIQUITY article (65: 767–95) Atholl Anderson presented a detailed analysis of radiocarbon dates to show that the settlement of New Zealand occurred later than previously thought. In this paper Anderson teams up with another proponent of ‘chronometric hygiene’, Matthew Spriggs (see A NTIQUITY 63: 587–613), to examine the dates for the colonization of the rest of East Polynesia. Once again the generally accepted dates for initial settlement are found wanting and a later chronology is suggested.

Radiocarbon and DNA evidence for a pre-Columbian introduction of Polynesian chickens to Chile

Two issues long debated among Pacific and American prehistorians are (i) whether there was a pre-Columbian introduction of chicken (Gallus gallus) to the Americas and (ii) whether Polynesian contact with South America might be identified archaeologically, through the recovery of remains of unquestionable Polynesian origin. We present a radiocarbon date and an ancient DNA sequence from a single chicken bone recovered from the archaeological site of El Arenal-1, on the Arauco Peninsula, Chile. These results not only provide firm evidence for the pre-Columbian introduction of chickens to the Americas, but strongly suggest that it was a Polynesian introduction.

Faunal collapse, landscape change and settlement history in Remote Oceania

Substantial anthropogenic environmental change occurred in Remote Oceania following the first arrival of people at 3000 BP and their spread throughout the region by 700 BP. It included numerous faunal extinctions, widespread deforestation and the erosion and re-deposition of sediments, to which are attributed various consequences for cultural development. The issue considered here is whether an explanation of anthropogenic change could extend to variations in settlement history between Remote Oceanic islands. Most of those were inhabited continuously, especially in the older settled area, but in East Polynesia settlement is thought to have declined on several islands and it was abandoned in many others. Consideration of the type and scale of anthropogenic changes indicates no correlation with variations in settlement history. Anthropogenic changes might be regarded as constants of the settlement process. Late Holocene climatic patterns, ecological complexity and isolation with its effect on the availability of subsistence choices, may have been more influential variables.

Indo-European and Asian origins for Chilean and Pacific chickens revealed by mtDNA

European chickens were introduced into the American continents by the Spanish after their arrival in the 15th century. However, there is ongoing debate as to the presence of pre-Columbian chickens among Amerindians in South America, particularly in relation to Chilean breeds such as the Araucana and Passion Fowl. To understand the origin of these populations, we have generated partial mitochondrial DNA control region sequences from 41 native Chilean specimens and compared them with a previously generated database of ≈1,000 domestic chicken sequences from across the world as well as published Chilean and Polynesian ancient DNA sequences. The modern Chilean sequences cluster closely with haplotypes predominantly distributed among European, Indian subcontinental, and Southeast Asian chickens, consistent with a European genetic origin. A published, apparently pre-Columbian, Chilean specimen and six pre-European Polynesian specimens also cluster with the same European/Indian subcontinental/Southeast Asian sequences, providing no support for a Polynesian introduction of chickens to South America. In contrast, sequences from two archaeological sites on Easter Island group with an uncommon haplogroup from Indonesia, Japan, and China and may represent a genetic signature of an early Polynesian dispersal. Modeling of the potential marine carbon contribution to the Chilean archaeological specimen casts further doubt on claims for pre-Columbian chickens, and definitive proof will require further analyses of ancient DNA sequences and radiocarbon and stable isotope data from archaeological excavations within both Chile and Polynesia.

A model of prehistoric collecting on the rocky shore

Abstract Selective resource exploitation patterns in prehistory are often explained in terms of cultural preference, but this paper argues that a non-cultural explanation based upon zoological models of consumer choice may be equally valid. A model of shell-fishing behaviour concerning the relationship of abundance and yield is developed and used to predict that rocky shore collectors should ignore all factors other than the individual size of shellfish and that, in doing so, they would become progressively selective in their collecting patterns. Data from prehistoric rocky shore shell middens in Palliser Bay, New Zealand, indicates several phases of progressively selective collecting over a period of 600 years and these patterns appear best explicable in terms of the model.

Prehistoric human impacts on Rapa, French Polynesia

New excavations and survey on the island of Rapa have shown that a rockshelter was occupied by early settlers around AD 1200 and the first hill forts were erected about 300 years later. Refortification occurred up to the contact period and proliferated around AD 1700. Taro cultivation in terraced pond-fields kept pace with the construction of forts. The authors make a connection between fort-building and making pond-fields, demonstrating that the pressure on resources provoked both the intensification of agriculture and hostility between the communities of the small island.