Alaska Peninsula Stable Isotope and Radioisotope Chemistry: A Study in Temporal and Adaptive Diversity

Purified bone collagen from a small suite of human remains recovered at three sites on the Alaska Peninsula (Port Moller, Brooks River, and Mink Island) were analyzed for stable carbon and nitrogen isotope chemistry and were accelerator radiocarbon dated. Because samples sizes were small and faunal isotope chemistry lacking, results should be considered preliminary. However, these data indicate that each locality was represented by a somewhat different suite of subsistence strategies and covered a distinct temporal span. Port Moller burials (n = 7) from the Hot Springs site date to a calibrated 2σ range of 3547–1388 BP. Although marine foods clearly made the greatest contribution to these diets, individuals were not as heavily reliant on high-trophic-level marine taxa as eastern Aleutian groups to the west, given their intake of salmon and evidence of caribou hunting. Brooks River burials (n = 9) expressed an inland foraging focus with significant reliance on caribou and spawning salmon and covered a calibrated 2σ range of 1484–381 BP. In contrast, individuals from Mink Island (n = 7), dating to cal. 666–292 BP, were heavily reliant on high-trophic-level marine prey similar to but not as enriched isotopically as the Aleut, perhaps a consequence of limited access to caribou and greater reliance on invertebrates. This pattern suggests that prehistoric economic strategies on the Alaska Peninsula were diverse, characterized by fine-tuned adaptations to local ecological settings, perhaps mediated by ethnic factors and territorial and social pressures. Pay-Per-View Download To access this article as a PDF pay-per-view download via BioOne, please click here

Temporal and Dietary Reconstruction of Past Aleut Populations: Stable- and Radio-Isotope Evidence Revisited

A recent accelerator radiocarbon study of Eastern Aleutian human remains that Ales Hrdlicka collected in the 1930s contradicts his long-standing assertion that brachycranic Neo-Aleut people, moving west along the island chain at ca. 1000 BP, replaced the dolichocranic Paleo-Aleut population. Radiocarbon dates for Paleo-Aleut individuals ranged from ca. 3400 to 400 cal BP, covering the entire temporal span of the study and indicating that Paleo-Aleuts coexisted in the study area with Neo-Aleuts from ca. AD 1000 until well into the 16th century. Shortly after publication of that study, the curating institution informed the authors that a small number of cataloguing errors with respect to cranial category had come to their attention. Subsequent corrections made to cranial categories have strengthened temporal patterning characteristic of this data set. Mortuary practices and genetic and dietary patterning also distinguish Paleo-Aleut from Neo-Aleut groups. The stable isotope chemistry of their diets indicates that Neo-Aleuts relied on higher-trophic-level marine taxa than Paleo-Aleuts and, within that category of taxa, on more offshore rather than nearshore-feeding pinnipeds.Une étude récente réalisée au moyen d’un accélérateur pour la datation par le carbone 14 visant des dépouilles mortelles d’Aléoutes de l’Est recueillies par Ales Hrdlicka dans les années 1930 vient contredire son affirmation de longue date selon laquelle le peuple néo-aléoute brachycrâne, se déplaçant vers l’ouest le long de l’arc insulaire vers l’an 1000 BP, a remplacé la population paléo-aléoute dolichocrâne. La datation par le carbone 14 pour les individus paléo-aléoutes variait environ entre 3400 et 400 cal. BP, ce qui recouvrait toute la durée temporelle de l’étude et indiquait que les Paléo-Aléoutes ont coexisté avec les Néo-Aléoutes dans la région visée par l’étude d’environ 1000 AD jusqu’au XVIe siècle avancé. Peu après la publication de cette étude, l’établissement responsable de la conservation a signalé aux auteurs qu’un petit nombre d’erreurs de catalogage avaient été décelées relativement à la catégorie crânienne. Les corrections qui ont été subséquemment apportées aux catégories crâniennes se sont trouvé à renforcer les caractéristiques de typification temporelle de cet ensemble de données. Les pratiques mortuaires de même que les caractéristiques génétiques et alimentaires ont également permis de distinguer les Paléo-Aléoutes des Néo-Aléoutes. La chimie des isotopes stables de leurs alimentations indique que les Néo-Aléoutes dépendaient de taxons marins de niveau trophique plus élevé que les Paléo-Aléoutes et, au sein de cette catégorie de taxon, qu’ils dépendaient davantage de pinnipèdes extracôtiers que côtiers

Hrdlič̌ka's Aleutian population-replacement hypothesis: a radiometric evaluation

Journal ArticleIn a 1945 monograph, Hrdlička argued that, at 1,000 BP, Paleo-Aleut people on Umnak Island were replaced by Neo-Aleut groups moving west along the island chain. His argument was based on cranial measurements of skeletal remains from Chaluka Midden and mummified remains from Kagamil and Ship Rock burial caves. By the 1980s, researchers had concluded that the transition demonstrated by Hrdlička, from a high oblong to a low-vaulted wide face, was merely one example of a global trend in cranial morphology and therefore population replacement had not occurred

Hrdlička’s Aleutian Population‐Replacement Hypothesis: A Radiometric Evaluation

In a 1945 monograph, Hrdlika argued that, at 1,000 BP, PaleoAleut people on Umnak Island were replaced by NeoAleut groups moving west along the island chain. His argument was based on cranial measurements of skeletal remains from Chaluka Midden and mummified remains from Kagamil and Ship Rock burial caves. By the 1980s, researchers had concluded that the transition demonstrated by Hrdlika, from a high oblong to a lowvaulted wide face, was merely one example of a global trend in cranial morphology and therefore population replacement had not occurred. Calibrated accelerator radiocarbon dates on purified bone collagen from 80 individuals indicate that PaleoAleuts were the oldest population in the Aleutians, with a time depth of ca. 4,000 years, that Paleo and NeoAleuts were fully contemporary on Umnak Island after 1,000 BP, and that the former continued to bury their dead as inhumations long after the introduction of NeoAleut mummification practices. These results as well as features of the Aleut dietary, genetic, and material record suggest that the appearance of NeoAleut people represents an influx of closely related people characterized by greater social complexity and that social disparities that may have existed between Paleo and NeoAleuts were largely subsumed in the social and demographic upheaval following Russian contact

Inferring Population Continuity Versus Replacement with aDNA: A Cautionary Tale from the Aleutian Islands

In The Aleutian and Commander Islands and Their Inhabitants (Philadelphia: Wistar Institute of Anatomy and Biology, 1945), Hrdlička proposed a population replacement event in the Aleutian Islands approximately 1,000 years ago based on a perceived temporal shift in cranial morphology. However, the archaeological record indicates cultural, and presumed population, continuity for more than 4,000 years. We use mtDNA haplogroup data in the series of prehistoric eastern Aleutian samples (n = 86) studied craniometrically by Hrdlička to test alternative hypotheses regarding population continuity or replacement in the region. This molecular characterization, in conjunction with direct dating of individual specimens, provided increased resolution for hypothesis testing. Results indicate an apparent shift in mtDNA haplogroup frequencies in the eastern Aleutians approximately 1,000 years ago, in concert with changes in mortuary practices and isotopic signatures reflecting resource acquisition strategies. The earliest Aleut populations were characterized by a high frequency of haplogroup A, as are most modern populations of the North American arctic. Later prehistoric peoples in the Aleutians were characterized by a high frequency of haplogroup D and a correspondingly lower frequency of haplogroup A, a pattern typified by modern Aleut populations

Socioecological dynamics structuring the spread of farming in the North American Basin-Plateau Region

Journal ArticleThe spread of agriculture is a major driver of social and environmental change throughout 25 the Holocene, yet experimental and ethnographic data indicate that farming is less profitable than foraging, so why would individuals choose to adopt agriculture leading to its expansion? Ideal distribution models offer one framework to answer this question: Individuals should adopt less profitable subsistence strategies and occupy more marginal environments when local population density increases competition to the point where the suitability of the best strategies and habitats 30 becomes equal to what can be gained in poorer strategies and habitats. Coupling radiocarbon-dated archaeological sites with a validated measure of agricultural suitability, we evaluate the emergence of farming in the Basin-Plateau region of North America. In line with these predictions, our results show that farming first occurs in the more suitable Colorado Plateau physiographic region, and only spreads into the less suitable Great Basin physiographic region after population density on the Plateau 35 increases. This produces an approximate 300- to 400-year lag between the onset of farming on the Plateau and in the Basin. These findings support the ideal distribution hypothesis for the spread of farming, and suggest a general socioecological process that may help explain global patterns in the timing and tempo of agricultural expansions

Supplementary Materials: Socioecological dynamics structuring the spread of farming in the North American Basin-Plateau Region

journal articleThis document includes the code used to complete the analysis presented in the manuscript "Socioecological Dynamics Structuring the Spread of Farming in the North American Basin-Plateau Region" in Environmental 15 Archaeology

Stable Isotope Chemistry, Population Histories and Late Prehistoric Subsistence Change in the Aleutian Islands

Aleut population history has been a topic of debate since the earliest archaeological investigations in the region. In this paper, we use stable isotope chemistry to evaluate the hypothesis that two distinct groups of people, Paleo- and Neo-Aleut, occupied the eastern Aleutians after 1000 BP. This study focuses on 80 sets of directly dated eastern Aleutian burial assemblages from Chaluka midden, Shiprock Island and Kagamil Island. We use a linear mixing model informed by isotopic analysis of two large Aleut faunal assemblages to address temporal and spatial variation in human carbon and nitrogen stable isotope data from these sites. The patterning we report addresses both Aleut demographic and economic prehistory, illustrating a transition in both at ca. 1000 BP. Our results suggests that the Chaluka diet, dominated by Paleo-Aleut inhumations, differed in both trophic level and foraging location from the other two sites for much of the past 4000 years. Trends in our data also suggest that individuals from Shiprock and Kagamil burial caves, primarily Neo-Aleuts, had enough access to higher trophic level foods to differentiate their bone chemistries from those buried in Chaluka midden. These trends in diet, recently reported genetic differences, as well as the introduction of novel mortuary practices at ca. 1000 BP, suggest that Neo-Aleuts do represent a population new to the eastern Aleutians