RESUMO
The Caribbean was one of the last parts of the Americas to be settled by humans, but how and when the islands were first occupied remains a matter of debate. Ancient DNA can help answering these questions, but the work has been hampered by poor DNA preservation. We report the genome sequence of a 1,000-year-old Lucayan Taino individual recovered from the site of Preacher's Cave in the Bahamas. We sequenced her genome to 12.4-fold coverage and show that she is genetically most closely related to present-day Arawakan speakers from northern South America, suggesting that the ancestors of the Lucayans originated there. Further, we find no evidence for recent inbreeding or isolation in the ancient genome, suggesting that the Lucayans had a relatively large effective population size. Finally, we show that the native American components in some present-day Caribbean genomes are closely related to the ancient Taino, demonstrating an element of continuity between precontact populations and present-day Latino populations in the Caribbean.
Assuntos
Indígena Americano ou Nativo do Alasca/genética , Genoma Humano/genética , Migração Humana/estatística & dados numéricos , Adulto , Arqueologia , Bahamas , DNA Antigo , DNA Mitocondrial/genética , Feminino , Genética Populacional , Genômica , Hispânico ou Latino/genética , História Antiga , Migração Humana/história , Humanos , Masculino , Paleontologia , Filogenia , Adulto JovemRESUMO
We present the high-quality genome sequence of a â¼45,000-year-old modern human male from Siberia. This individual derives from a population that lived before-or simultaneously with-the separation of the populations in western and eastern Eurasia and carries a similar amount of Neanderthal ancestry as present-day Eurasians. However, the genomic segments of Neanderthal ancestry are substantially longer than those observed in present-day individuals, indicating that Neanderthal gene flow into the ancestors of this individual occurred 7,000-13,000 years before he lived. We estimate an autosomal mutation rate of 0.4 × 10(-9) to 0.6 × 10(-9) per site per year, a Y chromosomal mutation rate of 0.7 × 10(-9) to 0.9 × 10(-9) per site per year based on the additional substitutions that have occurred in present-day non-Africans compared to this genome, and a mitochondrial mutation rate of 1.8 × 10(-8) to 3.2 × 10(-8) per site per year based on the age of the bone.
Assuntos
Fósseis , Genoma Humano/genética , Alelos , Animais , Cromossomos Humanos Par 12/genética , Dieta , Evolução Molecular , Humanos , Hibridização Genética/genética , Masculino , Dados de Sequência Molecular , Taxa de Mutação , Homem de Neandertal/genética , Filogenia , Densidade Demográfica , Dinâmica Populacional , Análise de Componente Principal , Análise de Sequência de DNA , SibériaRESUMO
The Middle to Upper Paleolithic transition is often linked with a bio-cultural shift involving the dispersal of modern humans outside of Africa, the concomitant replacement of Neanderthals across Eurasia, and the emergence of new technological traditions. The Zagros Mountains region assumes importance in discussions concerning this period as its geographic location is central to all pertinent hominin migration areas, pointing to both east and west. As such, establishing a reliable chronology in the Zagros Mountains is crucial to our understanding of these biological and cultural developments. Political circumstance, coupled with the poor preservation of organic material, has meant that a clear chronological definition of the Middle to Upper Paleolithic transition for the Zagros Mountains region has not yet been achieved. To improve this situation, we have obtained new archaeological samples for AMS radiocarbon dating from three sites: Kobeh Cave, Kaldar Cave, and Ghar-e Boof (Iran). In addition, we have statistically modelled previously published radiocarbon determinations for Yafteh Cave (Iran) and Shanidar Cave (Iraqi Kurdistan), to improve their chronological resolution and enable us to compare the results with the new dataset. Bayesian modelling results suggest that the onset of the Upper Paleolithic in the Zagros Mountains dates to 45,000-40,250 cal BP (68.2% probability). Further chronometric data are required to improve the precision of this age range.
Assuntos
Hominidae , Paleontologia , África , Animais , Teorema de Bayes , Evolução Biológica , Fósseis , Humanos , Irã (Geográfico) , Espectrometria de Massas/métodos , Homem de Neandertal , Datação RadiométricaRESUMO
Recent palaeogenetic studies indicate a highly dynamic history in collared lemmings (Dicrostonyx spp.), with several demographical changes linked to climatic fluctuations that took place during the last glaciation. At the western range margin of D. torquatus, these changes were characterized by a series of local extinctions and recolonizations. However, it is unclear whether this pattern represents a local phenomenon, possibly driven by ecological edge effects, or a global phenomenon that took place across large geographical scales. To address this, we explored the palaeogenetic history of the collared lemming using a next-generation sequencing approach for pooled mitochondrial DNA amplicons. Sequences were obtained from over 300 fossil remains sampled across Eurasia and two sites in North America. We identified five mitochondrial lineages of D. torquatus that succeeded each other through time across Europe and western Russia, indicating a history of repeated population extinctions and recolonizations, most likely from eastern Russia, during the last 50 000 years. The observation of repeated extinctions across such a vast geographical range indicates large-scale changes in the steppe-tundra environment in western Eurasia during the last glaciation. All Holocene samples, from across the species' entire range, belonged to only one of the five mitochondrial lineages. Thus, extant D. torquatus populations only harbour a small fraction of the total genetic diversity that existed across different stages of the Late Pleistocene. In North American samples, haplotypes belonging to both D. groenlandicus and D. richardsoni were recovered from a Late Pleistocene site in south-western Canada. This suggests that D. groenlandicus had a more southern and D. richardsoni a more northern glacial distribution than previously thought. This study provides significant insights into the population dynamics of a small mammal at a large geographical scale and reveals a rather complex demographical history, which could have had bottom-up effects in the Late Pleistocene steppe-tundra ecosystem.
Assuntos
Arvicolinae/genética , Extinção Biológica , Variação Genética , Animais , Regiões Árticas , DNA Antigo/análise , DNA Mitocondrial/análise , Europa (Continente) , Fósseis , Pradaria , América do Norte , Filogenia , Dinâmica Populacional , Federação Russa , Análise de Sequência de DNA , TundraRESUMO
We report here the genome sequence of an ancient human. Obtained from approximately 4,000-year-old permafrost-preserved hair, the genome represents a male individual from the first known culture to settle in Greenland. Sequenced to an average depth of 20x, we recover 79% of the diploid genome, an amount close to the practical limit of current sequencing technologies. We identify 353,151 high-confidence single-nucleotide polymorphisms (SNPs), of which 6.8% have not been reported previously. We estimate raw read contamination to be no higher than 0.8%. We use functional SNP assessment to assign possible phenotypic characteristics of the individual that belonged to a culture whose location has yielded only trace human remains. We compare the high-confidence SNPs to those of contemporary populations to find the populations most closely related to the individual. This provides evidence for a migration from Siberia into the New World some 5,500 years ago, independent of that giving rise to the modern Native Americans and Inuit.
Assuntos
Criopreservação , Extinção Biológica , Genoma Humano/genética , Inuíte/genética , Emigração e Imigração/história , Genética Populacional , Genômica , Genótipo , Groenlândia , Cabelo , História Antiga , Humanos , Masculino , Fenótipo , Filogenia , Polimorfismo de Nucleotídeo Único/genética , Análise de Sequência de DNA , Sibéria/etnologiaRESUMO
It is commonly accepted that some of the latest dates for Neanderthal fossils and Mousterian industries are found south of the Ebro valley in Iberia at ca. 36 ka calBP (calibrated radiocarbon date ranges). In contrast, to the north of the valley the Mousterian disappears shortly before the Proto-Aurignacian appears at ca. 42 ka calBP. The latter is most likely produced by anatomically modern humans. However, two-thirds of dates from the south are radiocarbon dates, a technique that is particularly sensitive to carbon contaminants of a younger age that can be difficult to remove using routine pretreatment protocols. We have attempted to test the reliability of chronologies of 11 southern Iberian Middle and early Upper Paleolithic sites. Only two, Jarama VI and Zafarraya, were found to contain material that could be reliably dated. In both sites, Middle Paleolithic contexts were previously dated by radiocarbon to less than 42 ka calBP. Using ultrafiltration to purify faunal bone collagen before radiocarbon dating, we obtain ages at least 10 ka (14)C years older, close to or beyond the limit of the radiocarbon method for the Mousterian at Jarama VI and Neanderthal fossils at Zafarraya. Unless rigorous pretreatment protocols have been used, radiocarbon dates should be assumed to be inaccurate until proven otherwise in this region. Evidence for the late survival of Neanderthals in southern Iberia is limited to one possible site, Cueva Antón, and alternative models of human occupation of the region should be considered.
RESUMO
Archaeological bones are usually dated by radiocarbon measurement of extracted collagen. However, low collagen content, contamination from the burial environment, or museum conservation work, such as addition of glues, preservatives, and fumigants to "protect" archaeological materials, have previously led to inaccurate dates. These inaccuracies in turn frustrate the development of archaeological chronologies and, in the Paleolithic, blur the dating of such key events as the dispersal of anatomically modern humans. Here we describe a method to date hydroxyproline found in collagen (~10% of collagen carbon) as a bone-specific biomarker that removes impurities, thereby improving dating accuracy and confidence. This method is applied to two important sites in Russia and allows us to report the earliest direct ages for the presence of anatomically modern humans on the Russian Plain. These dates contribute considerably to our understanding of the emergence of the Mid-Upper Paleolithic and the complex suite of burial behaviors that begin to appear during this period.
Assuntos
Radioisótopos de Carbono/análise , Fósseis , Animais , Biomarcadores/análise , Osso e Ossos/química , Cromatografia Líquida de Alta Pressão , Colágeno/química , Rituais Fúnebres/história , História Antiga , Hidroxiprolina/análise , Espectrometria de Massas , Nitrogênio/análise , Federação Russa , Fatores de TempoRESUMO
Recent archaeological discoveries have revealed that pigment use, beads, engravings, and sophisticated stone and bone tools were already present in southern Africa 75,000 y ago. Many of these artifacts disappeared by 60,000 y ago, suggesting that modern behavior appeared in the past and was subsequently lost before becoming firmly established. Most archaeologists think that San hunter-gatherer cultural adaptation emerged 20,000 y ago. However, reanalysis of organic artifacts from Border Cave, South Africa, shows that the Early Later Stone Age inhabitants of this cave used notched bones for notational purposes, wooden digging sticks, bone awls, and bone points similar to those used by San as arrowheads. A point is decorated with a spiral groove filled with red ochre, which closely parallels similar marks that San make to identify their arrowheads when hunting. A mixture of beeswax, Euphorbia resin, and possibly egg, wrapped in vegetal fibers, dated to â¼40,000 BP, may have been used for hafting. Ornaments include marine shell beads and ostrich eggshell beads, directly dated to â¼42,000 BP. A digging stick, dated to â¼39,000 BP, is made of Flueggea virosa. A wooden poison applicator, dated to â¼24,000 BP, retains residues with ricinoleic acid, derived from poisonous castor beans. Reappraisal of radiocarbon age estimates through bayesian modeling, and the identification of key elements of San material culture at Border Cave, places the emergence of modern hunter-gatherer adaptation, as we know it, to â¼44,000 y ago.
Assuntos
Cavernas , Cultura , Animais , Arqueologia , Osso e Ossos/anatomia & histologia , Datação Radiométrica , África do SulRESUMO
The transition from the Middle Stone Age (MSA) to the Later Stone Age (LSA) in South Africa was not associated with the appearance of anatomically modern humans and the extinction of Neandertals, as in the Middle to Upper Paleolithic transition in Western Europe. It has therefore attracted less attention, yet it provides insights into patterns of technological evolution not associated with a new hominin. Data from Border Cave (KwaZulu-Natal) show a strong pattern of technological change at approximately 44-42 ka cal BP, marked by adoption of techniques and materials that were present but scarcely used in the previous MSA, and some novelties. The agent of change was neither a revolution nor the advent of a new species of human. Although most evident in personal ornaments and symbolic markings, the change from one way of living to another was not restricted to aesthetics. Our analysis shows that: (i) at Border Cave two assemblages, dated to 45-49 and >49 ka, show a gradual abandonment of the technology and tool types of the post-Howiesons Poort period and can be considered transitional industries; (ii) the 44-42 ka cal BP assemblages are based on an expedient technology dominated by bipolar knapping, with microliths hafted with pitch from Podocarpus bark, worked suid tusks, ostrich eggshell beads, bone arrowheads, engraved bones, bored stones, and digging sticks; (iii) these assemblages mark the beginning of the LSA in South Africa; (iv) the LSA emerged by internal evolution; and (v) the process of change began sometime after 56 ka.
Assuntos
Evolução Biológica , Cavernas , Adesividade , Animais , Sedimentos Geológicos , Humanos , África do Sul , Fatores de TempoRESUMO
We report here on the 2007 discovery, in perfect archaeological context, of part of the engraved and ocre-stained undersurface of the collapsed rockshelter ceiling from Abri Castanet, Dordogne, France. The decorated surface of the 1.5-t roof-collapse block was in direct contact with the exposed archaeological surface onto which it fell. Because there was no sedimentation between the engraved surface and the archaeological layer upon which it collapsed, it is clear that the Early Aurignacian occupants of the shelter were the authors of the ceiling imagery. This discovery contributes an important dimension to our understanding of the earliest graphic representation in southwestern France, almost all of which was discovered before modern methods of archaeological excavation and analysis. Comparison of the dates for the Castanet ceiling and those directly obtained from the Chauvet paintings reveal that the "vulvar" representations from southwestern France are as old or older than the very different wall images from Chauvet.
Assuntos
Arte/história , Fósseis , Datação Radiométrica/métodos , Animais , Arqueologia/métodos , Teorema de Bayes , Osso e Ossos , França , Geografia , História Antiga , Hominidae , HumanosRESUMO
The Uluzzian, one of Europe's 'transitional' technocomplexes, has gained particular significance over the past three years when the only human remains associated with it were attributed to modern humans, instead of Neanderthals as previously thought. The position of the Uluzzian at stratified sequences, always overlying late Mousterian layers and underlying early Upper Palaeolithic ones, highlights its significance in understanding the passage from the Middle to Upper Palaeolithic, as well as the replacement of Neanderthals by modern humans in southeastern Mediterranean Europe. Despite several studies investigating aspects of its lithic techno-typology, taxonomy and material culture, the Uluzzian chronology has remained extremely poorly-known, based on a handful of dubious chronometric determinations. Here we aim to elucidate the chronological aspect of the technocomplex by presenting an integrated synthesis of new radiocarbon results and a Bayesian statistical approach from four stratified Uluzzian cave sequences in Italy and Greece (Cavallo, Fumane, Castelcivita and Klissoura 1). In addition to building a reliable chronological framework for the Uluzzian, we examine its appearance, tempo-spatial spread and correlation to previous and later Palaeolithic assemblages (Mousterian, Protoaurignacian) at the relevant regions. We conclude that the Uluzzian arrived in Italy and Greece shortly before 45,000 years ago and its final stages are placed at â¼39,500 years ago, its end synchronous (if not slightly earlier) with the Campanian Ignimbrite eruption.
Assuntos
Fósseis , Homem de Neandertal , Tecnologia/história , Animais , Antropologia Física , Grécia Antiga , História Antiga , Humanos , Itália , Datação RadiométricaRESUMO
Advances in direct radiocarbon dating of Neanderthal and anatomically modern human (AMH) fossils and the development of archaeostratigraphic chronologies now allow refined regional models for Neanderthal-AMH coexistence. In addition, they allow us to explore the issue of late Neanderthal survival in regions of Western Eurasia located within early routes of AMH expansion such as the Caucasus. Here we report the direct radiocarbon ((14)C) dating of a late Neanderthal specimen from a Late Middle Paleolithic (LMP) layer in Mezmaiskaya Cave, northern Caucasus. Additionally, we provide a more accurate chronology for the timing of Neanderthal extinction in the region through a robust series of 16 ultrafiltered bone collagen radiocarbon dates from LMP layers and using Bayesian modeling to produce a boundary probability distribution function corresponding to the end of the LMP at Mezmaiskaya. The direct date of the fossil (39,700 ± 1,100 (14)C BP) is in good agreement with the probability distribution function, indicating at a high level of probability that Neanderthals did not survive at Mezmaiskaya Cave after 39 ka cal BP ("calendrical" age in kiloannum before present, based on IntCal09 calibration curve). This challenges previous claims for late Neanderthal survival in the northern Caucasus. We see striking and largely synchronous chronometric similarities between the Bayesian age modeling for the end of the LMP at Mezmaiskaya and chronometric data from Ortvale Klde for the end of the LMP in the southern Caucasus. Our results confirm the lack of reliably dated Neanderthal fossils younger than â¼ 40 ka cal BP in any other region of Western Eurasia, including the Caucasus.
Assuntos
Fósseis , Hominidae , Paleontologia/métodos , Animais , Ásia Ocidental , Teorema de Bayes , Europa Oriental , História Antiga , Humanos , Datação RadiométricaRESUMO
The Pleistocene was an epoch of extreme climatic and environmental changes. How individual species responded to the repeated cycles of warm and cold stages is a major topic of debate. For the European fauna and flora, an expansion-contraction model has been suggested, whereby temperate species were restricted to southern refugia during glacial times and expanded northwards during interglacials, including the present interglacial (Holocene). Here, we test this model on the red deer (Cervus elaphus) a large and highly mobile herbivore, using both modern and ancient mitochondrial DNA from the entire European range of the species over the last c. 40,000 years. Our results indicate that this species was sensitive to the effects of climate change. Prior to the Last Glacial Maximum (LGM) haplogroups restricted today to South-East Europe and Western Asia reached as far west as the UK. During the LGM, red deer was mainly restricted to southern refugia, in Iberia, the Balkans and possibly in Italy and South-Western Asia. At the end of the LGM, red deer expanded from the Iberian refugium, to Central and Northern Europe, including the UK, Belgium, Scandinavia, Germany, Poland and Belarus. Ancient DNA data cannot rule out refugial survival of red deer in North-West Europe through the LGM. Had such deer survived, though, they were replaced by deer migrating from Iberia at the end of the glacial. The Balkans served as a separate LGM refugium and were probably connected to Western Asia with genetic exchange between the two areas.
Assuntos
Mudança Climática , Cervos/genética , Genética Populacional , Animais , Teorema de Bayes , DNA Mitocondrial/genética , Europa (Continente) , Variação Genética , Haplótipos , Funções Verossimilhança , Dados de Sequência Molecular , Filogenia , Filogeografia , Datação Radiométrica , Análise de Sequência de DNARESUMO
Two sites of the Neandertal-associated Middle Paleolithic of Iberia, dated to as early as approximately 50,000 years ago, yielded perforated and pigment-stained marine shells. At Cueva de los Aviones, three umbo-perforated valves of Acanthocardia and Glycymeris were found alongside lumps of yellow and red colorants, and residues preserved inside a Spondylus shell consist of a red lepidocrocite base mixed with ground, dark red-to-black fragments of hematite and pyrite. A perforated Pecten shell, painted on its external, white side with an orange mix of goethite and hematite, was abandoned after breakage at Cueva Antón, 60 km inland. Comparable early modern human-associated material from Africa and the Near East is widely accepted as evidence for body ornamentation, implying behavioral modernity. The Iberian finds show that European Neandertals were no different from coeval Africans in this regard, countering genetic/cognitive explanations for the emergence of symbolism and strengthening demographic/social ones.
Assuntos
Antropologia , Corantes , Minerais , Moluscos , Animais , EspanhaRESUMO
Nitrogen isotope ratio analysis (δ15N) of animal tissue is widely used in archaeology and palaeoecology to investigate diet and ecological niche. Data interpretations require an understanding of nitrogen isotope compositions at the base of the food web (baseline δ15N). Significant variation in animal δ15N has been recognised at various spatiotemporal scales and related to changes both in baseline δ15N, linked to environmental and climatic influence on the terrestrial nitrogen cycle, and animal ecology. Isoscapes (models of isotope spatial variation) have proved a useful tool for investigating spatial variability in biogeochemical cycles in present-day marine and terrestrial ecosystems, but so far, their application to palaeo-data has been more limited. Here, we present time-sliced nitrogen isoscapes for late Pleistocene and early Holocene Europe (c. 50,000 to 10,000 years BP) using herbivore collagen δ15N data. This period covers the Last Glacial-Interglacial Transition, during which significant variation in the terrestrial nitrogen cycle occurred. We use generalized linear mixed modelling approaches for interpolation and test models which both include and exclude climate covariate data. Our results show clear changes in spatial gradients of δ15N through time. Prediction of the lowest faunal δ15N values in northern latitudes after, rather than during, the Last Glacial Maximum is consistent with the Late Glacial Nitrogen Excursion (LGNE). We find that including climatic covariate data does not significantly improve model performance. These findings have implications for investigating the drivers of the LGNE, which has been linked to increased landscape moisture and permafrost thaw, and for understanding changing isotopic baselines, which are fundamental for studies investigating diets, niche partitioning, and migration of higher trophic level animals.
Assuntos
Ecossistema , Nitrogênio , Animais , Nitrogênio/análise , Isótopos de Nitrogênio/análise , Cadeia Alimentar , Europa (Continente) , Isótopos de Carbono/análiseRESUMO
The rockshelter of Mochi, on the Ligurian coast of Italy, is often used as a reference point in the formation of hypotheses concerning the arrival of the Aurigancian in Mediterranean Europe. Yet, the site is poorly known. Here, we describe the stratigraphic sequence based on new field observations and present 15 radiocarbon determinations from the Middle Palaeolithic (late Mousterian) and Early Upper Palaeolithic (Aurignacian and Gravettian) levels. The majority of dates were produced on humanly modified material, specifically marine shell beads, which comprise some of the oldest directly-dated personal ornaments in Europe. The radiocarbon results are incorporated into a Bayesian statistical model to build a new chronological framework for this key Palaeolithic site. A tentative correlation of the stratigraphy to palaeoclimatic records is also attempted.
Assuntos
Evolução Biológica , Evolução Cultural/história , Fósseis , Animais , Arqueologia , Teorema de Bayes , Sedimentos Geológicos , História Antiga , Humanos , Itália , Moluscos , Datação RadiométricaRESUMO
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 approximately 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 approximately 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.
Assuntos
Ecossistema , Emigração e Imigração/história , Fósseis , Animais , História Antiga , Humanos , Nova Zelândia , Polinésia/etnologia , Ratos , Ratos EndogâmicosRESUMO
Most scholars of the subject consider that a pre-Columbian transpacific transfer accounts for the historical role of American sweet potato Ipomoea batatas as the kumara staple of Indigenous New Zealand/Aotearoa Maori in cooler southwestern Polynesia. Archaeologists have recorded evidence of ancient Polynesian I. batatas cultivation from warmer parts of generally temperate-climate Aotearoa, while assuming that the archipelago's traditional Murihiku region in southern South Island/Te Waipounamu was too cold to grow and store live Polynesian crops, including relatively hardy kumara. However, archaeological pits in the form of seasonal Maori kumara stores (rua kumara) have been discovered unexpectedly at Purakaunui on eastern Murihuku's Otago coast, over 200 km south of the current Polynesian limit of record for premodern I. batatas production. Secure pit deposits that incorporate starch granules with I. batatas characteristics are radiocarbon-dated within the decadal range 1430-1460 CE at 95% probability in a Bayesian age model, about 150 years after Polynesians first settled Te Waipounamu. These archaeological data become relevant to a body of Maori oral history accounts and traditional knowledge (matauranga) concerning southern kumara, incorporating names, memories, landscape features and seemingly enigmatic references to an ancient Murihiku crop presence. Selected components of this lore are interpreted through comparative exegesis for correlation with archaeological science results in testable models of change. In a transfer and adaptation model, crop stores if not seasonal production technologies also were introduced from a warmer, agricultural Aotearoa region into dune microclimates of 15th-century coastal Otago to mitigate megafaunal loss, and perhaps to support Polynesia's southernmost residential chiefdom in its earliest phase. A crop loss model proposes that cooler seasonal temperatures of the post-1450 Little Ice Age and (or) political change constrained kumara supply and storage options in Murihiku. The loss model allows for the disappearance of kumara largely, but not entirely, as a traditional Otago crop presence in Maori social memory.