Doctoral Dissertation Improvement Grant: Early Human Settlement of the High-Altitude Pucuncho Basin, Southern Peruvian Andes

Under the direction of Dr. Daniel Sandweiss, Mr. Kurt Rademaker will collect data for his doctoral dissertation research. His project focuses on determining the timing of early human occupation in the Andes Mountains. Human settlement of Earth\u27s high-altitude mountains and plateaus is among the most recent of our species\u27 bio-geographic expansions. Current anthropological models emphasize the physiographic and biological challenges inherent to these extreme environments to explain a lack of pre-11,000 year-old archaeological evidence above 3500 m elevation in the Andes and on the high Tibetan Plateau. However few archaeological studies targeting hunter-gatherer sites have been conducted in these areas.This interdisciplinary project\u27s primary objectives are to better understand the timing, environmental setting, and adaptations involved in human settlement of the high Andes of southern Peru. Rademaker\u27s investigations so far have led to the discovery of early archaeological sites in the Pucuncho Basin, a wetland oasis ringed by glaciated volcanoes and situated at ~4500 m (~14,760 ft) elevation. One of these sites, Cuncaicha rockshelter, has yielded preliminary radiocarbon dates that indicate an initial settlement of this high-altitude area between 12,400 and 11,800 years ago. These dates establish Cuncaicha as one of the oldest known directly-dated archaeological sites in the Andes Mountains and the highest ice-age site yet discovered anywhere in the world.The final laboratory phase of this dissertation project, to be funded by NSF, will significantly strengthen the preliminary chronological data from Cuncaicha shelter and provide information on the development of local habitats important to Andean animals and people for successful colonization of high-altitude zones. Rademaker will obtain additional radiocarbon dates for the Cuncaicha rockshelter site and the nearby Rio Blanco geologic section. These archaeological and paleoecologic data will be directly comparable with local glacial geologic records, and these comparisons will shed light on links between late ice-age climatic change, the formation of Andean habitats, and early human settlement of extreme high-altitude environments. This project will have several broad impacts. By conducting pretreatment of samples at the University of Arizona accelerator mass spectrometry lab, Rademaker will receive valuable training in archaeological scientific methodology. Completion of this dissertation project will yield numerous peer-reviewed journal publications and ultimately lead to publication of an edited volume for a more general audience. The project team has given, and will continue to give, guest lectures at Peruvian and North American universities, in addition to presenting scientific results at professional meetings at home and abroad. Since 2005 this project has provided limited temporary economic benefits to some local inhabitants of the Pucuncho Basin who have assisted in surveys and excavation and provided related support for the project team. The team has brought medicine, vitamins, and educational materials for the school children in Pucuncho\u27s three villages and worked to instill a conservation ethic about archaeological remains in the region. Continued scientific work in the Pucuncho area, which will build upon this Ph.D. dissertation project, will undoubtedly reinforce this ethic and yield additional valuable information on climatic change, ecology, and human prehistory

Biocultural Evidence of Precise Manual Activities in an Early Holocene Individual of the High-Altitude Peruvian Andes

OBJECTIVES: Cuncaicha, a rockshelter site in the southern Peruvian Andes, has yielded archaeological evidence for human occupation at high elevation (4,480 masl) during the Terminal Pleistocene (12,500–11,200 cal BP), Early Holocene (9,500–9,000 cal BP), and later periods. One of the excavated human burials (Feature 15‐06), corresponding to a middle‐aged female dated to ~8,500 cal BP, exhibits skeletal osteoarthritic lesions previously proposed to reflect habitual loading and specialized crafting labor. Three small tools found in association with this burial are hypothesized to be associated with precise manual dexterity. MATERIALS AND METHODS: Here, we tested this functional hypothesis through the application of a novel multivariate methodology for the three‐dimensional analysis of muscle attachment surfaces (entheses). This original approach has been recently validated on both lifelong‐documented anthropological samples as well as experimental studies in nonhuman laboratory samples. Additionally, we analyzed the three‐dimensional entheseal shape and resulting moment arms for muscle opponens pollicis. RESULTS: Results show that Cuncaicha individual 15‐06 shows a distinctive entheseal pattern associated with habitual precision grasping via thumb‐index finger coordination, which is shared exclusively with documented long‐term precision workers from recent historical collections. The separate geometric morphometric analysis revealed that the individual\u27s opponens pollicis enthesis presents a highly projecting morphology, which was found to strongly correlate with long joint moment arms (a fundamental component of force‐producing capacity), closely resembling the form of Paleolithic hunter‐gatherers from diverse geo‐chronological contexts of Eurasia and North Africa. DISCUSSION: Overall, our findings provide the first biocultural evidence to confirm that the lifestyle of some of the earliest Andean inhabitants relied on habitual and forceful precision grasping tasks

Lateglacial shifts in seasonality reconcile conflicting North Atlantic temperature signals

The accelerating flux of glacial meltwater to the oceans due to global warming is a potential trigger for future climate disturbance. Past disruption of Atlantic Ocean circulation, driven by melting of land-based ice, is linked in models to reduced ocean-atmosphere heat transfer and abrupt cooling during stadial events. The most recent stadial, the Younger Dryas (YD), is traditionally viewed as a severe cooling centered on the North Atlantic but with hemispheric influence. However, indications of summer warmth question whether YD cooling was truly year-round or restricted to winter. Here, we present a beryllium-10-dated glacier record from the north-east North Atlantic, coupled with 2-D glacier-climate modeling, to reconstruct Lateglacial summer air temperature patterns. Our record reveals that, contrary to the prevailing model, the last glacial advance in Scotland did not occur during the YD but predated the stadial, while the YD itself was characterized by warming-driven deglaciation. We argue that these apparently paradoxical findings can be reconciled with regional and global climate events by invoking enhanced North Atlantic seasonality—with anomalously cold winters but warming summers—as an intrinsic response to globally increased poleward heat fluxes

Reconstructing the Deep Population History of Central and South America

We report genome-wide ancient DNA from 49 individuals forming four parallel time transects in Belize, Brazil, the Central Andes, and the Southern Cone, each dating to at least 9,000 years ago. The common ancestral population radiated rapidly from just one of the two early branches that contributed to Native Americans today. We document two previously unappreciated streams of gene flow between North and South America. One affected the Central Andes by 4,200 years ago, while the other explains an affinity between the oldest North American genome associated with the Clovis culture and the oldest Central and South Americans from Chile, Brazil, and Belize. However, this was not the primary source for later South Americans, as the other ancient individuals derive from lineages without specific affinity to the Clovis-associated genome, suggesting a population replacement that began at least 9,000 years ago and was followed by substantial population continuity in multiple regions

Ten millennia of hepatitis B virus evolution

Hepatitis B virus (HBV) has been infecting humans for millennia and remains a global health problem, but its past diversity and dispersal routes are largely unknown. We generated HBV genomic data from 137 Eurasians and Native Americans dated between ~10,500 and ~400 years ago. We date the most recent common ancestor of all HBV lineages to between ~20,000 and 12,000 years ago, with the virus present in European and South American hunter-gatherers during the early Holocene. After the European Neolithic transition, Mesolithic HBV strains were replaced by a lineage likely disseminated by early farmers that prevailed throughout western Eurasia for ~4000 years, declining around the end of the 2nd millennium BCE. The only remnant of this prehistoric HBV diversity is the rare genotype G, which appears to have reemerged during the HIV pandemic

Early Human Settlement of the High-Altitude Pucuncho Basin, Peruvian Andes

This interdisciplinary thesis presents results from field and laboratory investigations of archaeological sites in a ~150-km coast-highland corridor in southern Peru, aimed at better understanding the Terminal Pleistocene biogeographic expansion of humans into the high-altitude Andes and possible early coast-highland links. I integrated a number of approaches to understand late-glacial landscapes and to locate early hunter- gatherer archaeological sites, including creation of a digital database of archaeological radiocarbon data, geochemical characterization of the Alca obsidian source, quantitative geographic information systems (GIS) predictive modeling, region-level archaeological survey, geophysical surveys, test excavations, and systematic surface collections, and accelerator mass spectrometry (AMS) dating of the Cuncaicha rockshelter (4488 m elevation), the highest Pleistocene archaeological site yet discovered in the world. This interdisciplinary work in the high Peruvian Andes has yielded evidence that despite colder temperatures, more extensive glaciers, and low-oxygen conditions, successful human colonization of high-altitude environments began ~12,400-12,000 years ago at the end of the last ice age

Geoarchaeological Investigations of the Waynuna Site and the Alca Obsidian Source, Peru

This M.S. thesis presents results from field and laboratory investigations of the Alca highland obsidian (volcanic glass) source and Wayñuna, a Preceramic highland archaeological site previously identified close to a geological deposit of Alca obsidian in southern Peru\u27s Cotahuasi Valley. Obsidian artifacts found within Terminal Pleistocene (13,000-11,200) strata at coastal site Quebrada Jaguay (QJ-280) were sourced to the Alca deposit in the Cotahuasi Valley some 155 km distant, suggesting contact between specific coastal and highland locales during the period of earliest settlement of South America. This Quebrada Jaguay-Alca connection suggested that additional, analogous Paleoindian sites should be located near Alca obsidian source deposits. Excavations at Waynuna revealed an intact Terminal Preceramic (ca. 4,000-3,600 cal yr B.P.) occupation, so Wayñuna does not constitute an analogous site to Quebrada Jaguay. This work at Wayñuna, however, offers the first excavated data of a Preceramic settlement in the Cotahuasi Valley, and the analysis of Wayñuna\u27s lithic assemblage reported in this thesis constitutes the first in-depth study of highland Preceramic lithic technology for this region. The Wayñuna assemblage obtained from a limited investigation of a domestic house context is indicative of a systematic and carefull

Estudo ecomorfológico da variação craniana em populações pré-históricas do Perú

El objetivo del presente trabajo es analizar la variación craneométrica en una muestra de individuos del Holoceno temprano/medio al tardío de Perú. Para esto, se registraron ocho medidas lineales en el esqueleto facial y bóveda craneana de 301 individuos procedentes de 19 sitios arqueológicos, los cuales se encuentran ubicados en cuatro biomas. Se exploró la variación en la forma y tamaño del cráneo entre individuos de distintos biomas y sitios arqueológicos mediante un Análisis de Componentes Principales y Análisis Discriminante. Complementariamente, se evaluó la afinidad morfológica entre las muestras mediante el cálculo de distancias de Mahalanobis y un análisis de clúster jerárquico de Ward. Asimismo, se estimó el efecto del bioma, sitio arqueológico, altitud, y cronología para explicar el patrón de variación morfológico observado a través de MANOVA. Los resultados mostraron que existen similitudes entre individuos de distintas cronologías; los individuos del Holoceno temprano/medio presentan gran variación morfológica; las muestras más recientes presentan diferencias en la longitud del cráneo, variables que describen la apertura nasal, pero también el subcomponente alveolar, lo cual a su vez se encuentra asociado a la diversidad de altitud y sitio arqueológico de procedencia. Se discuten los resultados en relación a trabajos previos que estudiaron muestras de Perú, y otras áreas de América del Sur. De esta manera se espera contribuir a la discusión de los debates actuales sobre el poblamiento de Sudamérica, especialmente en torno a las posibles adaptaciones locales.The aim of this paper is to analyze the craniometric variation in a sample of early/middle to late Holocene individuals from Peru. For this, eight linear measurements were recorded on the facial skeleton and cranial vault of 301 individuals coming from 19 archaeological sites located in four different biomes. Principal Component and Discriminant Analysis allowed exploring the skull shape and size variation. Complementarily, morphological affinity among the samples was studied by calculating Mahalanobis distances and Ward’s hierarchical cluster analysis. Additionally, the effects of biome, altitude, archaeological site, and chronology on morphology were evaluated through a MANOVA. The results showed that there are similarities between individuals of different chronology; the early/middle Holocene individuals show large morphological variation; and the most recent samples show differences in the length of the skull and nasal variables, but also in the alveolar subcomponent, which in turn are associated with the diversity in altitude and archaeological site of origin. The results are discussed in the context of previous works that studied samples from Peru, as well as some other areas of South America. In this way we hope to contribute to the current debates about the population of South America, especially in relation to local adaptation.O objetivo deste trabalho é analisar a variação craniométrica em uma amostra de indivíduos do Holoceno inicial/médio ao final do Peru. Para isto, foram registradas oito medidas lineares no esqueleto facial e abóbada craniana de 301 indivíduos procedentes de 19 sítios arqueológicos, os quais estão localizados em quatro biomas. Explorou-sea variação na forma e tamanho do crânio entre indivíduos de diferentes biomas e sítios arqueológicos por meio de uma Análise de Componentes Principais e Análise Discriminante. Além disso, a afinidade morfológica entre as amostras foi avaliada pelo cálculo de distâncias de Mahalanobis e uma análise de cluster hierárquica de Ward. Ademais, estimou-se o efeito do bioma, sítio arqueológico, altitude e cronologia para explicar o padrão de variação morfológica observado através de MANOVA. Os resultados mostraram que existem semelhanças entre indivíduos de diferentes cronologias, os indivíduos do Holoceno inicial/médio apresentam grande variação morfológica, as amostras mais recentes mostram diferenças no comprimento do crânio, variáveis que descrevem a abertura nasal, mas também o subcomponente alveolar, que, por sua vez, está associada à diversidade de altitude e sítio arqueológico de origem. Os resultados são discutidos em relação a trabalhos prévios que estudaram amostras do Peru, e outras áreas da América do Sul. Desta maneira, espera-se contribuir para a discussão dos debates atuais sobre o povoamento da América do Sul, principalmente em torno das possíveis adaptações locais.Facultad de Ciencias Naturales y Muse

Estudo ecomorfológico da variação craniana em populações pré-históricas do Perú

El objetivo del presente trabajo es analizar la variación craneométrica en una muestra de individuos del Holoceno temprano/medio al tardío de Perú. Para esto, se registraron ocho medidas lineales en el esqueleto facial y bóveda craneana de 301 individuos procedentes de 19 sitios arqueológicos, los cuales se encuentran ubicados en cuatro biomas. Se exploró la variación en la forma y tamaño del cráneo entre individuos de distintos biomas y sitios arqueológicos mediante un Análisis de Componentes Principales y Análisis Discriminante. Complementariamente, se evaluó la afinidad morfológica entre las muestras mediante el cálculo de distancias de Mahalanobis y un análisis de clúster jerárquico de Ward. Asimismo, se estimó el efecto del bioma, sitio arqueológico, altitud, y cronología para explicar el patrón de variación morfológico observado a través de MANOVA. Los resultados mostraron que existen similitudes entre individuos de distintas cronologías; los individuos del Holoceno temprano/medio presentan gran variación morfológica; las muestras más recientes presentan diferencias en la longitud del cráneo, variables que describen la apertura nasal, pero también el subcomponente alveolar, lo cual a su vez se encuentra asociado a la diversidad de altitud y sitio arqueológico de procedencia. Se discuten los resultados en relación a trabajos previos que estudiaron muestras de Perú, y otras áreas de América del Sur. De esta manera se espera contribuir a la discusión de los debates actuales sobre el poblamiento de Sudamérica, especialmente en torno a las posibles adaptaciones locales.The aim of this paper is to analyze the craniometric variation in a sample of early/middle to late Holocene individuals from Peru. For this, eight linear measurements were recorded on the facial skeleton and cranial vault of 301 individuals coming from 19 archaeological sites located in four different biomes. Principal Component and Discriminant Analysis allowed exploring the skull shape and size variation. Complementarily, morphological affinity among the samples was studied by calculating Mahalanobis distances and Ward’s hierarchical cluster analysis. Additionally, the effects of biome, altitude, archaeological site, and chronology on morphology were evaluated through a MANOVA. The results showed that there are similarities between individuals of different chronology; the early/middle Holocene individuals show large morphological variation; and the most recent samples show differences in the length of the skull and nasal variables, but also in the alveolar subcomponent, which in turn are associated with the diversity in altitude and archaeological site of origin. The results are discussed in the context of previous works that studied samples from Peru, as well as some other areas of South America. In this way we hope to contribute to the current debates about the population of South America, especially in relation to local adaptation.O objetivo deste trabalho é analisar a variação craniométrica em uma amostra de indivíduos do Holoceno inicial/médio ao final do Peru. Para isto, foram registradas oito medidas lineares no esqueleto facial e abóbada craniana de 301 indivíduos procedentes de 19 sítios arqueológicos, os quais estão localizados em quatro biomas. Explorou-sea variação na forma e tamanho do crânio entre indivíduos de diferentes biomas e sítios arqueológicos por meio de uma Análise de Componentes Principais e Análise Discriminante. Além disso, a afinidade morfológica entre as amostras foi avaliada pelo cálculo de distâncias de Mahalanobis e uma análise de cluster hierárquica de Ward. Ademais, estimou-se o efeito do bioma, sítio arqueológico, altitude e cronologia para explicar o padrão de variação morfológica observado através de MANOVA. Os resultados mostraram que existem semelhanças entre indivíduos de diferentes cronologias, os indivíduos do Holoceno inicial/médio apresentam grande variação morfológica, as amostras mais recentes mostram diferenças no comprimento do crânio, variáveis que descrevem a abertura nasal, mas também o subcomponente alveolar, que, por sua vez, está associada à diversidade de altitude e sítio arqueológico de origem. Os resultados são discutidos em relação a trabalhos prévios que estudaram amostras do Peru, e outras áreas da América do Sul. Desta maneira, espera-se contribuir para a discussão dos debates atuais sobre o povoamento da América do Sul, principalmente em torno das possíveis adaptações locais.Dossier: Ocupaciones tempranas en América: voces desde el Cono SurFacultad de Ciencias Naturales y Muse

Estudo ecomorfológico da variação craniana em populações pré-históricas do Perú

El objetivo del presente trabajo es analizar la variación craneométrica en una muestra de individuos del Holoceno temprano/medio al tardío de Perú. Para esto, se registraron ocho medidas lineales en el esqueleto facial y bóveda craneana de 301 individuos procedentes de 19 sitios arqueológicos, los cuales se encuentran ubicados en cuatro biomas. Se exploró la variación en la forma y tamaño del cráneo entre individuos de distintos biomas y sitios arqueológicos mediante un Análisis de Componentes Principales y Análisis Discriminante. Complementariamente, se evaluó la afinidad morfológica entre las muestras mediante el cálculo de distancias de Mahalanobis y un análisis de clúster jerárquico de Ward. Asimismo, se estimó el efecto del bioma, sitio arqueológico, altitud, y cronología para explicar el patrón de variación morfológico observado a través de MANOVA. Los resultados mostraron que existen similitudes entre individuos de distintas cronologías; los individuos del Holoceno temprano/medio presentan gran variación morfológica; las muestras más recientes presentan diferencias en la longitud del cráneo, variables que describen la apertura nasal, pero también el subcomponente alveolar, lo cual a su vez se encuentra asociado a la diversidad de altitud y sitio arqueológico de procedencia. Se discuten los resultados en relación a trabajos previos que estudiaron muestras de Perú, y otras áreas de América del Sur. De esta manera se espera contribuir a la discusión de los debates actuales sobre el poblamiento de Sudamérica, especialmente en torno a las posibles adaptaciones locales.The aim of this paper is to analyze the craniometric variation in a sample of early/middle to late Holocene individuals from Peru. For this, eight linear measurements were recorded on the facial skeleton and cranial vault of 301 individuals coming from 19 archaeological sites located in four different biomes. Principal Component and Discriminant Analysis allowed exploring the skull shape and size variation. Complementarily, morphological affinity among the samples was studied by calculating Mahalanobis distances and Ward’s hierarchical cluster analysis. Additionally, the effects of biome, altitude, archaeological site, and chronology on morphology were evaluated through a MANOVA. The results showed that there are similarities between individuals of different chronology; the early/middle Holocene individuals show large morphological variation; and the most recent samples show differences in the length of the skull and nasal variables, but also in the alveolar subcomponent, which in turn are associated with the diversity in altitude and archaeological site of origin. The results are discussed in the context of previous works that studied samples from Peru, as well as some other areas of South America. In this way we hope to contribute to the current debates about the population of South America, especially in relation to local adaptation.O objetivo deste trabalho é analisar a variação craniométrica em uma amostra de indivíduos do Holoceno inicial/médio ao final do Peru. Para isto, foram registradas oito medidas lineares no esqueleto facial e abóbada craniana de 301 indivíduos procedentes de 19 sítios arqueológicos, os quais estão localizados em quatro biomas. Explorou-sea variação na forma e tamanho do crânio entre indivíduos de diferentes biomas e sítios arqueológicos por meio de uma Análise de Componentes Principais e Análise Discriminante. Além disso, a afinidade morfológica entre as amostras foi avaliada pelo cálculo de distâncias de Mahalanobis e uma análise de cluster hierárquica de Ward. Ademais, estimou-se o efeito do bioma, sítio arqueológico, altitude e cronologia para explicar o padrão de variação morfológica observado através de MANOVA. Os resultados mostraram que existem semelhanças entre indivíduos de diferentes cronologias, os indivíduos do Holoceno inicial/médio apresentam grande variação morfológica, as amostras mais recentes mostram diferenças no comprimento do crânio, variáveis que descrevem a abertura nasal, mas também o subcomponente alveolar, que, por sua vez, está associada à diversidade de altitude e sítio arqueológico de origem. Os resultados são discutidos em relação a trabalhos prévios que estudaram amostras do Peru, e outras áreas da América do Sul. Desta maneira, espera-se contribuir para a discussão dos debates atuais sobre o povoamento da América do Sul, principalmente em torno das possíveis adaptações locais.Facultad de Ciencias Naturales y Muse