Thegn N. Ladefoged

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.

Variable Development of Dryland Agriculture in Hawaiʻi

Research in the leeward Kohala dryland agricultural field system on Hawaiʻi Island provides the opportunity to develop a fine‐grained chronology for its development—both expansion and intensification—using a combination of chronometric and relative dating. Two pathways for agricultural development are identified for this field system, the first beginning as early as the fourteenth century and the second after the mid‐seventeenth century. This chronology, combined with dating for residential features, religious sites, and territorial boundaries, makes it possible to link agricultural change with social and political dynamics in the late prehistoric period. This sequence is compared to four other relatively well‐dated dryland field systems on the islands of Maui, Molokaʻi, and Hawaiʻi. These systems can be assigned to either of the two pathways identified for Kohala, suggesting that dryland agricultural strategies can be sorted into (1) an earlier expansion and subsequent intensification in areas where conditions were better suited for such practices and (2) a later, more rapid expansion into and more limited intensification of areas associated with greater costs or risks. The second and later pathway for agricultural development is linked to earlier increases in populations living in more optimal locations, movement or expansion of these populations into marginal zones, regional population integration, and increasing surplus demands to fund chiefly ambitions involving territorial expansion.

Prehistoric and early historic agriculture at Maunga Orito, Easter Island (Rapa Nui), Chile

A long section adjacent to a former obsidian quarry on Easter Island (Rapa Nui) reveals a sequence of agricultural strategies, beginning with the clearing of palm trees in the twelfth century AD, and the making of an open garden growing yams and taro, that continued through the fifteenth century. The later phases between the seventeenth and nineteenth centuries include veneer and boulder gardens that reflect the broader strategy employed by the islanders to fight the increasingly arid soil.

DNA and Pacific Commensal Models: Applications, Construction, Limitations, and Future Prospects

ABSTRACT Components of the Pacific transported landscape have been used as proxies to trace the prehistoric movement of humans across the Pacific for almost two decades. Analyses of archaeological remains and DNA sequences of plants, animals, and microorganisms moved by or with humans have contributed to understanding prehistoric migration, trade, exchange, and sometimes revealed the geographic origins of particular plants and animals. This paper presents the basic elements of a DNA-based commensal model and discusses the phylogenetic and population genetic approaches these models employ. A clear delineation of the underlying assumptions of these models and the background information required to construct them have yet to appear in the literature. This not only provides a framework with which to construct a commensal model but also highlights gaps in current knowledge. The ways in which commensal models have enriched archaeological reconstructions will be highlighted, as will their current limitations. With these limitations in mind, options will be outlined for augmenting commensal models through the application of established techniques and new technologies in order to provide the best tools for reconstructing ancient human mobility and behavior in the Pacific and beyond.

High-precision dating of colonization and settlement in East Polynesia

Wilmshurst et al. (1) proposed recent and rapid colonization of East Polynesia based on analysis of 1,434 radiocarbon determinations. We commend the development of rigorous and replicable radiocarbon protocols that emphasize accuracy and precision, but we found (i) inaccuracies in their originally published supplementary data table, (ii) problems with their criteria for exclusion and inclusion of valid colonization estimators (i.e., Class 1 dates), and (iii) biases in their statistical analysis.

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

The Leeward Kohala Field System (LKFS) covering ∼60 km2 on Hawai‘i Island is one of the worlds 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.

Variation in Rapa Nui (Easter Island) land use indicates production and population peaks prior to European contact

Significance Our paper evaluates a long-standing debate and examines whether the prehistoric population of Rapa Nui experienced a significant demographic collapse prior to European contact in AD 1722. We have used dates from hydrated obsidian artifacts recovered from habitation sites as a proxy for land use over time. The analysis suggests region-specific dynamics that include the abandonment of leeward and interior locations. These temporal land-use patterns correlate with rainfall variation and soil quality. This analysis demonstrates that the concept of “collapse” is a misleading characterization of prehistoric human population dynamics. As a result, we see our approach as useful in the study of other prehistoric societies for which a sudden demographic collapse has been proposed in prehistory. Many researchers believe that prehistoric Rapa Nui society collapsed because of centuries of unchecked population growth within a fragile environment. Recently, the notion of societal collapse has been questioned with the suggestion that extreme societal and demographic change occurred only after European contact in AD 1722. Establishing the veracity of demographic dynamics has been hindered by the lack of empirical evidence and the inability to establish a precise chronological framework. We use chronometric dates from hydrated obsidian artifacts recovered from habitation sites in regional study areas to evaluate regional land-use within Rapa Nui. The analysis suggests region-specific dynamics including precontact land use decline in some near-coastal and upland areas and postcontact increases and subsequent declines in other coastal locations. These temporal land-use patterns correlate with rainfall variation and soil quality, with poorer environmental locations declining earlier. This analysis confirms that the intensity of land use decreased substantially in some areas of the island before European contact.

Soil Phosphorus and Agricultural Development in the Leeward Kohala Field System, Island of Hawai,i,

ABSTRACT The leeward Kohala Field System on the island of Hawai‘i was one of the most intensive pre–European contact dryland agricultural systems. Archaeological and soil analysis has documented changes in soil nutrients over time. Soils were collected under agricultural field walls of different relative ages within the Kohala Field System. These field walls preserved soil from the time of their construction (between ca. A.D. 1400 and 1800), so soil samples from underneath older field walls have been exposed to a shorter period of cultivation than the soils under more recent field walls. Total P and P:Nb ratios of these buried soils were greater under walls than in once-cultivated surface soils, and greater under older walls than under younger walls. These results suggest that precontact cultivation decreased soil P reserves in this intensive agricultural landscape.

Erosion, Geological History, and Indigenous Agriculture: A Tale of Two Valleys

Irrigated pondfields and rainfed field systems represented alternative pathways of agricultural intensification that were unevenly distributed across the Hawaiian Archipelago prior to European contact, with pondfields on wetter soils and older islands and rainfed systems on fertile, moderate-rainfall upland sites on younger islands. The spatial separation of these systems is thought to have contributed to the dynamics of social and political organization in pre-contact Hawai’i. However, deep stream valleys on older Hawaiian Islands often retain the remains of rainfed dryland agriculture on their lower slopes. We evaluated why rainfed agriculture developed on valley slopes on older but not younger islands by comparing soils of Pololū Valley on the young island of Hawai’i with those of Hālawa Valley on the older island of Moloka’i. Alluvial valley-bottom and colluvial slope soils of both valleys are enriched 4–5-fold in base saturation and in P that can be weathered, and greater than 10-fold in resin-extractable P and weatherable Ca, compared to soils of their surrounding uplands. However, due to an interaction of volcanically driven subsidence of the young island of Hawai’i with post-glacial sea level rise, the side walls of Pololū Valley plunge directly into a flat valley floor, whereas the alluvial floor of Hālawa Valley is surrounded by a band of fertile colluvial soils where rainfed agricultural features were concentrated. Only 5% of Pololū Valley supports colluvial soils with slopes between 5° and 12° (suitable for rainfed agriculture), whereas 16% of Hālawa Valley does so. The potential for integrated pondfield/rainfed valley systems of the older Hawaiian Islands increased their advantage in productivity and sustainability over the predominantly rainfed systems of the younger islands.

Residential chronology, household subsistence, and the emergence of socioeconomic territories in leeward Kohala, Hawai'i Island

Previous research in leeward Kohala, Hawai‘i Island, has determined that the Leeward Kohala Field System (LKFS), a vast agricultural zone covering ~60 km2, developed between the 14th and 18th centuries AD. Additional analyses have documented the establishment of traditional socioeconomic territories, known as ahupua‘a, in tandem with the expansion of the field system. This article further refines the chronology of human settlement and socioeconomic development in leeward Kohala through the analysis of deposits associated with prehistoric residences. Based upon survey and excavation, we present a chronology for Hawaiian household transition and economic development in 2 study areas of leeward Kohala, spanning the field system to the coast. Forty-nine radiocarbon dates from short-lived plant materials and five 230Th dates on corals from residential and ritual features are synthesized into 3 temporal periods, which allow for comparison of residential size, distribution, number, and associated faunal materials from archaeological deposits. Changes in household composition and economy are suggested to have developed in tandem with the establishment of individual ahupua‘a and land divisions within them, and the further development of agricultural production.