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The Late-Holocene history of hydroclimatic variability in the Atacama Desert offers insights into the effects of precipitation and humans on ecosystems in one of the most extremely arid regions of the world. However, understanding the effects of regional precipitation variability in relation to local ecological stressors remains to be fully resolved. Here, we present a pollen-based qualitative precipitation reconstruction derived from fossil rodent middens recovered from two sites near Laguna Roja (LRO; n = 25) and Isluga (ISL; n = 15) in the Atacama highlands (19°S) of northern Chile. At LRO, the fossil pollen record shows multi-centennial hydroclimatic anomalies during the last millennium, with wetter than present phases at 1155–1130, 865–670, and 215–80 cal yrs BP, and similar to present conditions between 1005 and 880 cal yrs BP. In contrast, the ISL record shows a wet phase during 1115–840 cal yrs BP, suggesting that meso-ecological processes were as important in vegetation turnover as regional hydroclimate anomalies. Wetter conditions derived from LRO partially overlap with the Medieval Climate Anomaly (865–670 cal yrs BP) and with the latest part of the Little Ice Age (215–80 cal yrs BP). Furthermore, no strong anthropogenic signal was identified possibly related to the remote location of the records. Palynological diversity analyses evidence increasing diversification of plant communities during wet events at both sites. In correlation to existing regional hydroclimatic records from the Western Andes, our precipitation reconstruction verifies that centennial-scale changes in the strength of the South American Summer Monsoon (SASM) and partial influence of El Niño-like (ENSO) conditions drove vegetation turnover in the Atacama Desert during the last millennium.

Stable isotope studies have revolutionised our understanding of food webs, subsistence, mobility and their change through time. In the Andes, dietary stable isotopic studies have often focused on t...

Forecasting the effects of climate change on the distribution of Andean trees (Polylepis, Rosaceae) is important to understand how species respond to climate variability and to assess their resilience to the ongoing climate crisis. Here, paleodistribution modelling is used to assess distribution shifts of 17 Polylepis species during the Last Glacial Maximum (LGM), mid-Holocene (MH), and the Anthropocene in the central Andes. Species distribution models (SDMs) were computed by combining presence records and current climatic conditions using Maxent and projected onto three climatic scenarios for the LGM (~22,000 yr BP), the MH (~6,000 yr BP), and the Anthropocene (1,970–2,000). Subsequently, current refugia hotspots were identified by intersecting suitable habitat over the LGM, MH, and anthropogenic conditions for all the studied species. SDMs for the LGM and MH showed a contraction of climate suitable habitat for most of the species in comparison to the Anthropocene. Four current refugia hotspots were identified: central Cordillera of Peru, Lake Titicaca basin, western Cordillera of Bolivia, and northern Chile. In general, SDMs were consistent with patterns proposed with pollen records, and partially with available phylogeographic studies. Current hotspots are highly important areas for the conservation of Polylepis and associated biota. This study assists in understanding distribution shifts over millennia of Andean tree species in response to climate change and identifying key conservation areas for the delineation of future conservation strategies.

As the Inca Empire expanded across the South American Andes during the fifteenth and sixteenth centuries AD, Lake Titicaca became its mythical place of origin and the location of a pilgrimage complex on the Island of the Sun. This complex included an underwater reef where stone boxes containing miniature figurines of gold, silver and shell were submerged as ritual offerings. This article reports a newly discovered stone offering box from a reef close to the lake's north-eastern shore. The location, content and broader socio-cultural context of Inca sacrifices are examined to illuminate the religious and social meaning of underwater ritual offerings at Lake Titicaca., SCOPUS: ar.j, info:eu-repo/semantics/published

The onset of plant cultivation is one of the most important cultural transitions in human history1–4. Southwestern Amazonia has previously been proposed as an early centre of plant domestication, on the basis of molecular markers that show genetic similarities between domesticated plants and wild relatives4–6. However, the nature of the early human occupation of southwestern Amazonia, and the history of plant cultivation in this region, are poorly understood. Here we document the cultivation of squash (Cucurbita sp.) at about 10,250 calibrated years before present (cal. yr bp), manioc (Manihot sp.) at about 10,350 cal. yr bp and maize (Zea mays) at about 6,850 cal. yr bp, in the Llanos de Moxos (Bolivia). We show that, starting at around 10,850 cal. yr bp, inhabitants of this region began to create a landscape that ultimately comprised approximately 4,700 artificial forest islands within a treeless, seasonally flooded savannah. Our results confirm that the Llanos de Moxos is a hotspot for early plant cultivation and demonstrate that—ever since their arrival in Amazonia—humans have markedly altered the landscape, with lasting repercussions for habitat heterogeneity and species conservation. Archaeological evidence that anthropic landscape changes and crop cultivation in southwestern Amazonia began about 10,000–11,000 years ago confirms that the region is a centre of early plant domestication.

The Lake Titicaca basin was one of the major centers for cultural development in the ancient world. This lacustrine environment is unique in the high, dry Andean altiplano, and its aquatic and terrestrial resources are thought to have contributed to the florescence of complex societies in this region. Nevertheless, it remains unclear to what extent local aquatic resources, particularly fish, and the introduced crop, maize, which can be grown in regions along the lakeshores, contributed to facilitating sustained food production and population growth, which underpinned increasing social political complexity starting in the Formative Period (1400 BCE to 500 CE) and culminating with the Tiwanaku state (500 to 1100 CE). Here, we present direct dietary evidence from stable isotope analysis of human skeletal remains spanning over two millennia, together with faunal and floral reference materials, to reconstruct foodways and ecological interactions in southern Lake Titicaca over time. Bulk stable isotope analysis, coupled with compound-specific amino acid stable isotope analysis, allows better discrimination between resources consumed across aquatic and terrestrial environments. Together, this evidence demonstrates that human diets predominantly relied on C(3) plants, particularly quinoa and tubers, along with terrestrial animals, notably domestic camelids. Surprisingly, fish were not a significant source of animal protein, but a slight increase in C(4) plant consumption verifies the increasing importance of maize in the Middle Horizon. These results underscore the primary role of local terrestrial food resources in securing a nutritious diet that allowed for sustained population growth, even in the face of documented climate and political change across these periods.

The long term response of ancient societies to climate change has been a matter of global debate. Until recently, the lack of integrative studies between archaeological, palaeoecological, and palaeoclimatological data had prevented an evaluation of the relationship between climate change, distinct subsistence strategies, and cultural transformations across the largest rainforest of the world, Amazonia. Here, we review the most relevant cultural changes seen in the archaeological record of six different regions within Greater Amazonia during late pre-Columbian times. We compare the chronology of those cultural transitions with high-resolution regional palaeoclimate proxies, showing that, while some societies faced major reorganisation during periods of climate change, others were unaffected and even flourished. We propose that societies with intensive, specialised land-use systems were vulnerable to transient climate change. In contrast, land-use systems that relied primarily on polyculture agroforestry, resulting in the formation of enriched forests and fertile Amazonian Dark Earths in the long term, were more resilient to climate change.

Over several millennia, various native plant species in South America have been used for their healing and psychoactive properties. Chemical analysis of archaeological artifacts provides an opportunity to study the use of psychoactive plants in the past and to better understand ancient botanical knowledge systems. Liquid chromatography tandem mass spectrometry (LC-MS/MS) was used to analyze organic residues from a ritual bundle, radiocarbon dated to approximately 1,000 C.E., recovered from archaeological excavations in a rock shelter located in the Lípez Altiplano of southwestern Bolivia. The site is located at an elevation of ∼3,900 m above sea level and contains evidence of intermittent human occupations during the last 4,000 years. Chemical traces of bufotenine, dimethyltryptamine, harmine, and cocaine, including its degradation product benzoylecgonine, were identified, suggesting that at least three plants containing these compounds were part of the shamanic paraphernalia dating back 1,000 years ago, the largest number of compounds recovered from a single artifact from this area of the world, to date. This is also a documented case of a ritual bundle containing both harmine and dimethyltryptamine, the two primary ingredients of ayahuasca. The presence of multiple plants that come from disparate and distant ecological areas in South America suggests that hallucinogenic plants moved across significant distances and that an intricate botanical knowledge was intrinsic to pre-Columbian ritual practices.

Considerable debate surrounds the economic, political, and ideological systems that constitute primary state formation. Theoretical and empirical research emphasize the role of religion as a significant institution for promoting the consolidation and reproduction of archaic states. The Tiwanaku state developed in the Lake Titicaca Basin between the 5th and 12th centuries CE and extended its influence over much of the south-central Andes of South America. We report on recent discoveries from the first systematic underwater archaeological excavations in the Khoa Reef near the Island of the Sun, Bolivia. The depositional context and compositional properties of offerings consisting of ceramic feline incense burners, killed juvenile llamas, and sumptuary metal, shell, and lapidary ornaments allow us to reconstruct the structure and significance of cyclically repeated state rituals. Using new theoretical tools, we explain the role of these rituals in promoting the consolidation of the Tiwanaku polity., SCOPUS: ar.j, info:eu-repo/semantics/published

South America is well known for its abundance of Quaternary fossiliferous deposits, but well-preserved fossil remains from well-dated sites are scarce in the Atacama Desert and adjacent arid Andes. Here we report on a partially complete skeleton (46%) of a single young (ca. 3–4 years old) extinct horse discovered in the Salar de Surire, a salt flat located on the Andean altiplano of northern Chile (4,250 m asl). Comparative and osteometric morphological analyses identify the specimen as a South American endemic horse Hippidion saldiasi Roth, 1899. A direct AMS radiocarbon date on bone collagen yielded a calibrated age of 13,170 cal yr BP (2σ range: 13,300–13,060 cal yr BP) indicating that it lived near the end of the last glaciation. The body mass of the individual was calculated at approximately 326.4 kg, close to the upper limit of the larger sizes reported for the genus. Stable isotope evidence shows that the Salar de Surire horse relied on an almost 100% C3 diet that is mostly consistent with Hippidion specimens from other environments that also consumed either mixed C3/C4 or fully C3 diets. This finding is now the southernmost high-elevation record for this species and provides further evidence for the broad geographic and ecological distribution of this genus throughout southern South America.

Archaeologists and demographers increasingly employ aggregations of published radiocarbon (14C) dates as demographic proxies summarizing changes in human activity in past societies. Presently, summed probability densities (SPDs) of calibrated radiocarbon dates are the dominant method of using 14C dates to reconstruct demographic trends. Unfortunately, SPDs are incapable of converging on their true generating distributions even as the number of observations gets large. To overcome this problem, we propose a more principled alternative that combines finite mixture models and Bayesian inference to identify the generating distribution of a set of radiocarbon dates. Numerical simulations and an assessment of the statistical identifiability of our method demonstrate that it correctly converges on the generating distribution. We apply this novel end-to-end Bayesian approach to reconstruct prehistoric Maya demographic growth using a recently compiled Mesoamerican radiocarbon database. Our results show that the Maya Lowlands experienced a century of rapid growth rates (1%) during the Late Classic, followed by a rapid decrease in population during the Terminal Classic, and a subsequent more-modest resurgence in population during the Postclassic. Additionally, a detailed population reconstruction of the important political center of Tikal verifies that slow population growth between the Preclassic and Early Classic gave pace to rapid growth starting around AD 500 and peaking at the beginning of the eight century. Our proposed method verifies previous reconstructions based on settlement patterns and ceramics, but with far more precise time-resolution and characterization of uncertainty than has been possible.

Summary There are many unanswered questions about the population history of the Central and South Central Andes, particularly regarding the impact of large-scale societies, such as the Moche, Wari, Tiwanaku, and Inca. We assembled genome-wide data on 89 individuals dating from ∼9,000-500 years ago (BP), with a particular focus on the period of the rise and fall of state societies. Today’s genetic structure began to develop by 5,800 BP, followed by bi-directional gene flow between the North and South Highlands, and between the Highlands and Coast. We detect minimal admixture among neighboring groups between ∼2,000–500 BP, although we do detect cosmopolitanism (people of diverse ancestries living side-by-side) in the heartlands of the Tiwanaku and Inca polities. We also highlight cases of long-range mobility connecting the Andes to Argentina and the Northwest Andes to the Amazon Basin. Video Abstract, Graphical Abstract, Highlights • Ancient DNA transect reveals north-south substructure of Andean highlands by 5,800 BP • After 5,800 BP, gene flow mixed highland people with their neighbors • After 2,000 BP, striking genetic continuity through rise and fall of major cultures, Genome-wide data from 89 ancient humans illuminates the changes to the genetic landscape in the Central Andes over 9,000 years, revealing large-scale gene flow and cosmopolitan societies in the Tiwanaku and Inca polities.

Animal sacrifice has played an important role as a material expression of the ritual behavior practiced by different societies around the world. In the South American Andes, the ceremonial immolation of llamas is well documented by both ethnohistoric and ethnographic sources. Nevertheless, archaeological evidence of animal sacrifice remains poorly documented. In this paper, we report the burial of two young camelids from El Pacifico, a Formative Period ceremonial site located on the central coast of Peru. AMS radiocarbon dates suggest the ritual sacrifice occurred when the architecture of the site was no longer in use, around the time of the Inca conquest. Based on the presence of cut marks and fly pupae, we suggest that one of the camelids, a yearling llama, was sacrificed by removal of its heart and buried shortly thereafter. Similarly, given the location of cut marks and representation of skeletal parts, we infer that the second camelid was slaughtered for human consumption prior to burial. In accordance with documented Andean rites, archaeological evidence from El Pacifico suggests that practitioners of camelid sacrifice followed a behavioral script following the selection of the animal to its final interment. We hypothesize the costly performance of this ceremony at an ancestral sacred site was part of a social and political strategy for promoting intergroup social cohesion during the arrival of the Incas to the region.

Author(s): Capriles, Jose M.; Tripcevich, Nicholas; Nielsen, Axel E.; Glascock, Michael D.; Albarracin-Jordan, Juan; Santoro, Calogero M.

Current scientific evidence shows that humans colonized South America at least 15,000 years ago, but there are still many unknown aspects of this process, including the major and minor migratory routes involved, and the pattern of successive occupation of a diverse continental mosaic of ecosystems. In this context, the role of the Andean highlands (≥3400 meters above sea level) has been neglected, because of the supposedly harsh conditions for humans including hypoxia and cold climate. Nevertheless, the environmental and cultural resources available in the high Andes constitutes an important “megapatch” that should be assessed in terms of human settlement patterns. We review the evidence for late Pleistocene/early Holocene hunter-gatherer occupation of one part of this megapatch, the northern Chilean Dry Puna, in its palaeoecological context. We focus on lithic technology, faunal remains, radiocarbon dates, and other archaeological materials related to different social activities, which allow us to suggest that groups of hunter-gatherers organized and adapted their way of life to highland ecosystems through logistical mobility, and curatorial strategies for lithic tool kits that included projectile points and other formalized tools. The morphology and technological processes involved are recognized over vast territories along the high Andes. We identify this material expression as the high south central Andean Archaic hunter-gatherer tradition, which also featured long distance mobile settlement systems and communication processes over this broad and distinct megapatch. More speculatively, we outline the hypothesis that these highland ecosystems constituted a suitable migratory route that may have been key for the early peopling of the continent, and contrast it with the alternative hypothesis of the initially secondary and seasonally intermittent exploitation of this habitat by hunter-gatherers dispersing along the Pacific coastal corridor.

Archaeologists and demographers increasingly employ aggregations of published radiocarbon (14C) dates as demographic proxies summarizing changes in human activity in past societies. Presently, summed probability densities (SPDs) of calibrated radiocarbon dates are the dominant method of using 14C dates to reconstruct demographic trends. Unfortunately, SPDs are incapable of converging on the distribution that generated a set of radiocarbon measurements, even when the number of observations is large. To overcome this problem, we propose a more principled alternative that combines finite mixture models and end-to-end Bayesian inference. Numerical simulations and an assessment of the statistical identifiability of our method demonstrate that it correctly converges on the generating distribution for two important models, exponentials and finite Gaussian mixtures, at least if the same statistical model is used to fit the data as was used to generate the data. To further validate this approach, we apply it to a set of radiocarbon dates from the Maya city of Tikal. We show that an end-to-end approach reconstructs with high accuracy expert demographic reconstructions based on settlement patterns and ceramics, but with more precise time-resolution and characterization of uncertainty than has heretofore been possible. Future work should consider alternatives to finite Gaussian mixtures for fitting the generating distribution.

Understanding how human societies interacted with environmental changes is a major goal of archaeology and other socio-natural sciences. In this paper, we assess the human-environment interactions in the Pampa del Tamarugal (PDT) basin of the Atacama Desert over the last 13,000 years. By relying on a socio-environmental model that integrates ecosystem services with adaptive strategies, we review past climate changes, shifting environmental conditions, and the continuities and discontinuities in the nature and intensity of the human occupation of the PDT. As a result we highlight the importance of certain key resources such as water, an essential factor in the long-term trajectory of eco-historical change. Without water the outcome of human societies becomes hazardous.

Archaeological research indicates that hunter-gatherers altered landscapes in southwestern Amazonia as early as 10,000 years ago., The Amazon witnessed the emergence of complex societies after 2500 years ago that altered tropical landscapes through intensive agriculture and managed aquatic systems. However, very little is known about the context and conditions that preceded these social and environmental transformations. Here, we demonstrate that forest islands in the Llanos de Moxos of southwestern Amazonia contain human burials and represent the earliest settlements in the region between 10,600 and 4000 years ago. These archaeological sites and their contents represent the earliest evidence of communities that experienced conditions conducive to engaging with food production such as environmental stability, resource disturbance, and increased territoriality in the Amazonian tropical lowlands.

The social groups that initially inhabited the hyper arid core of the Atacama Desert of northern Chile during the late Pleistocene integrated a wide range of local, regional and supra regional goods and ideas for their social reproduction as suggested by the archaeological evidence contained in several open camps in Pampa del Tamarugal (PdT). Local resources for maintaining their every-day life, included stone raw material, wood, plant and animal fibers, game, and fresh water acquired within a radius of ∼30 km (ca. 1-2 days journey). At a regional scale, some goods were introduced from the Pacific coast (60-80 km to the west, ca. 3-4 days journey), including elongated rounded cobbles used as hammer stones in lithic production, and shells, especially from non-edible species of mollusks. From the Andes (ranging 80-150 km to the east, ca. 5-8 days of journey), they obtained camelid fiber, obsidian and a high-quality chalcedony, in addition to sharing knowledge on projectile point designs (Patapatane and Tuina type forms). Pieces of wood of a tropical forest tree species (Ceiba spp.) from the east Andean lowlands (600 km away, ca. 30 days of journey) were also brought to the PdT. While local goods were procured by the circulation of people within the PdT, the small number of foreign items would have been acquired through some sort of exchange networks that integrated dispersed local communities throughout several ecosystems. These networks may have been a key factor behind the success exhibited by these early huntergatherers in the hyper arid ecosystems of the Atacama Desert at the end of the Pleistocene. Different lines of archaeological evidence including open camps, workshop-quarries, lithic artifacts, archaeofaunal remains, plant and animal fibers and textiles, archaeobotanical remains, and paleoecological data show that people of the PdT managed a wide range of cultural items from the Pacific coast, the Andean highland and the tropical forest, that were integrated with resources gathered locally within the socio-cultural systems established by the end of the Pleistocene. These results are interpreted as material expressions of multi-scalar networking for resource management and other social material and immaterial requirements, which in other words, means that these people were actively connected to regional (coastal and highland), and supra-regional (trans-Andean) exchange networks from and out of the PdT. Los grupos sociales que inicialmente habitaban el núcleo hiperárido del Desierto de Atacama en el norte de Chile durante el Pleistoceno tardío integraron una amplia gama de bienes e ideas, locales, regionales y supra regionales, para su reproducción social, como lo sugieren las evidencias arqueológicas materiales recuperadas en varios campamentos al aire libre en Pampa del Tamarugal (PdT). Los recursos locales para mantener su vida diaria, incluían materias primas líticas, fibras de plantas y animales, presas de caza y agua dulce adquiridos en un radio de ̴30 km (ca. 1-2 días de viaje). A escala regional, se introdujeron algunos elementos desde la costa del Pacífico (60-80 km hacia el oeste, ca. 3 a 4 días de viaje), incluidos rodados redondeados alargados, utilizados como percutores en la producción lítica y conchas, especialmente de especies no comestibles de moluscos. Desde los Andes (80-150 km al este, ca. 5-8 días de viaje), obtuvieron fibra de camélido, obsidiana y una calcedonia de alta calidad, además de compartir conocimientos sobre diseños de puntas de proyectil (tipo Patapatane y Tuina). También se llevaron a la PdT trozos de madera de una especie de árbol de los bosques tropicales (Ceiba spp.) de las tierras bajas al este de los Andes (600 km de distancia, ca. 30 días de viaje). Mientras que los bienes locales fueron adquiridos por la circulación de personas dentro de la PdT, el pequeño número de artículos foráneos se adquirieron a través de redes de intercambio que integraron comunidades locales dispersas en varios ecosistemas; lo que debió ser un factor clave detrás del éxito demostrado por estos primeros cazadores-recolectores en los ecosistemas hiperáridos del Desierto de Atacama hacia el final del Pleistoceno. Diferentes líneas de evidencia arqueológica que incluyen campamentos al aire libre, talleres, canteras, artefactos líticos, restos arqueofaunales, fibras y textiles de plantas y animales, restos arqueobotánicos y datos paleoecológicos, muestran que la gente de la PdT manejaron una amplia gama de elementos culturales desde la costa del Pacífico, el altiplano andino y el bosque tropical, que se integraron a los recursos recolectados localmente dentro de los sistemas socioculturales establecidos al final del Pleistoceno. Estos resultados se interpretan como una expresión material de una red de múltiples escalas para la gestión de recursos y otros requisitos sociales e inmateriales, lo que en otras palabras, significaría que estos grupos sociales estaban conectados activamente con redes de interacción regionales (costa y tierras altas) y supra-regionales (transandinas) desde y hacia la PdT. Fil: Santoro, Calógero M.. Universidad de Tarapaca.; Chile Fil: Gayo, Eugenia M.. Centro de Ciencia del Clima y la Resiliencia; Chile. Universidad de Concepción; Chile Fil: Capriles Flores, Jose Mariano. State University of Pennsylvania; Estados Unidos Fil: Rivadeneira Valenzuela, Marcelo Michel. Comisión Nacional de Investigación Científica y Tecnológica. Centro de Investigación Regional. Centro de Estudios en Zonas Áridas; Chile. Universidad Católica del Norte; Chile. Universidad de La Serena; Chile Fil: Herrera, Katherine A.. Universite Paris Ouest Nanterre la Defense; Francia. Universidad de Tarapaca.; Chile Fil: Mandakovic, Valentina. No especifíca; Fil: Rallo, Mónica. No especifíca; Fil: Rech, Jason A.. University of Miami; Estados Unidos Fil: Cases, Bárbara. Universidad de Tarapaca.; Chile Fil: Briones, Luis. Museo Municipalidad de Pica; Chile Fil: Olguín, Laura. Universidad Católica del Norte, San Pedro de Atacama; Chile Fil: Valenzuela, Daniela. Universidad de Tarapaca.; Chile Fil: Borrero, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; Argentina Fil: Ugalde, Paula C.. University of Arizona; Estados Unidos. Universidad de Tarapaca.; Chile Fil: Rothhammer, Francisco. Universidad de Tarapaca.; Chile Fil: Latorre, Claudio. Pontificia Universidad Católica de Chile; Chile. Instituto de Ecología y Biodiversidad; Chile Fil: Szpak, Paul. Trent University; Canadá

From the perspective of Central and South America, the peopling of the New World was a complex process lasting thousands of years and involving multiple waves of Pleistocene and early Holocene period immigrants entering into the neotropics. These Paleoindian colonists initially brought with them technologies developed for adaptation to environments and resources found in North America. As the ice age ended across the New World people adapted more generalized stone tools to exploit changing environments and resources. In the neotropics these changes would have been pronounced as patchy forests and grasslands gave way to broadleaf tropical forests. We document a late Pleistocene/early Holocene stone tool tradition from Belize, located in southern Mesoamerica. This represents the first endogenous Paleoindian stone tool technocomplex recovered from well dated stratigraphic contexts for Mesoamerica. Previously designated Lowe, these artifacts share multiple features with contemporary North and South American Paleoindian tool types. Once hafted, these bifaces appear to have served multiple functions for cutting, hooking, thrusting, or throwing. The tools were developed at a time of technological regionalization reflecting the diverse demands of a period of pronounced environmental change and population movement. Combined stratigraphic, technological, and population paleogenetic data suggests that there were strong ties between lowland neotropic regions at the onset of the Holocene.

In the Lluta Valley, northern Chile, climate is hyperarid and vegetation is restricted to the valley floors and lowermost footslopes. Fossil tree trunks and leaves of predominantly Escallonia angustifolia, however, are abundant up to ∼15 m above the present valley floor, where they are intercalated with slope deposits, reflecting higher water levels in the past. A total of 17 samples have been radiocarbon dated, yielding ages between 38 and 15k cal a BP. The youngest ages of 15.4k cal a BP are interpreted as reflecting the beginning of river incision and lowering of the valley floor, impeding the further growth of trees at higher parts of the slopes. The most plausible scenario for this observation is intensified river incision after 15.4k cal a BP due to increased stream power and runoff from the Rio Lluta headwaters in the Western Cordillera and Altiplano corresponding to the highstand of the Tauca and Central Andean Pluvial Event (CAPE) wet phase.

Proboscideans are so-called ecosystem engineers and are considered key players in hypotheses about Late Pleistocene megafaunal extinctions. However, knowledge about the autoecology and chronology of the proboscideans in South America is still open to debate and raises controversial views. Here, we used a range of multiproxy approaches and new radiocarbon datings to study the autoecology of Chilean gomphotheres, the only group of proboscideans to reach South America during the Great American Biotic Interchange (∼3.1 to 2.7 million years before present). As part of this study, we analyzed stable isotopes, dental microwear, and dental calculus microfossils on gomphothere molars from 30 Late Pleistocene sites (31° to 42°S). These proxies provided different scales of temporal resolution, which were then combined to assess the dietary and habitat patterns of these proboscideans. The multiproxy study suggests that most foraging took place in relatively closed environments. In Central Chile, there is a positive correlation between lower δ13C values and an increasing consumption of arboreal/scrub elements. Analyses of dental microwear and calculus microfossils have verified these leaf-browsing feeding habits. From a comparative perspective, the dietary pattern of South American gomphotheres appears to be constrained more by resource availability than by the potential dietary range of the individual taxa. This multiproxy study is aimed at increasing knowledge of the life history of gomphotheres and thus follows an issue considered one of the greatest challenges for paleontology in South America, recently pointed out by the need to thoroughly understand the role of ecological engineers before making predictions about the consequences of ecosystem defaunation.

One of the less well-understood problems in paleoscience is the role of climate as a modulator of long-term changes in human demography, and, in turn, how changes in human demography influence climate because demography also determines how individuals choose to modify ecosystems. Our workshop compared the long-term interaction between climate, human population change and the organization of social systems to understand the coevolution of Social and Ecological Systems (SES). The feedbacks between climate, ecosystems and social systems may lead to threshold changes in the organization of SES (Anderies et al. 2013). Paleoscience is critical for understanding how and when interactions between climate, ecosystems, and human systems reach threshold-state changes. Such understanding is important because contemporary SES must adapt to population growth and climate change, and insights gained from past SES may informsustainable development in the contemporary world. Fil: Freeman, Jacob. State University of Utah; Estados Unidos Fil: Gil, Adolfo Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina Fil: Cárdenas, M. L.. University of Reading; Reino Unido Fil: Byers, D. A.. State University of Utah; Estados Unidos Fil: Cannon, M. B.. State University of Utah; Estados Unidos Fil: Capriles, J. M.. State University of Pennsylvania; Estados Unidos Fil: Latorre, C.. Pontificia Universidad Católica de Chile; Chile

Andean wetlands or bofedales are commonly used by indigenous communities for livestock production. Decisions regarding management of bofedales involve the active participation of local people and their social institutions. Consequently, any action addressing emerging challenges must be implemented in coordination and agreement with local actors. This decision process requires an understanding of the local socioeconomic and cultural dynamics, especially those related to land and natural resource management. In many Andean communities, the ayllu is the institution that governs decisions on regional land use. However, in the face of increasing challenges such as climate change and population growth, use of the ayllu has declined in favor of individual decision-making. Here we discuss how the Andean camelid herders of Sajama National Park in highland Bolivia rely on both the ayllu and family-level decision-making to manage their pastoralist landscapes, including their bofedales. Using a rights mappin...

The Lake Titicaca Basin is one of the regions in the world where both primary village and state formation occurred in prehistory. Although agriculture has been discussed as the central engine fueling these processes, fish and other aquatic resources were significant but little-understood components of the region's ancient economy. In this paper, we use zooarchaeological analysis of faunal remains from 367 flotation samples recovered from five archaeological sites to discuss the interplay between fishing, environmental change, and the emergence of sociopolitical complexity in the Taraco Peninsula of Lake Titicaca. Our results suggest that fishing comprised a significant component of the local inhabitants' diet between 1500 BC and 1100 AD. The intensity of fish procurement, however, varied through time and independently of both climatic and population change. We interpret variation in fish consumption through time as a product of group and individual decisions to optimize resource use in a context of dynamic environmental and sociopolitical variability. © 2014 Elsevier Inc.

For the last 150 y scholars have focused upon the roles of intentional breeding and genetic isolation as fundamental to understanding the process of animal domestication. This analysis of ethnoarchaeological, archaeological, and genetic data suggests that long-term gene flow between wild and domestic stocks was much more common than previously assumed, and that selective breeding of females was largely absent during the early phases of animal domestication. These findings challenge assumptions about severe genetic bottlenecks during domestication, expectations regarding monophyletic origins, and interpretations of multiple domestications. The findings also raise new questions regarding ways in which behavioral and phenotypic domestication traits were developed and maintained.

The domestication of llamas and alpacas was fundamental for the cultural and economic development of Andean societies, but the origins of camelid pastoralism as a distinct mode of socioeconomic organization remain little understood. Whereas most archaeological interpretations of prehispanic highland societies emphasize the transition from hunting-gathering to agriculture as a process marked by the establishment of agricultural sedentary villages, other subsistence and mobility strategies have been for the most part overlooked. A case in point is the Wankarani cultural complex from the Central Altiplano of Bolivia, which has been interpreted as an example of an early village-based sedentary society. Here, I argue that a model of mobile pastoralism based on ethnoarchaeological research better explains the Central Altiplano's Formative period archaeological record. Recently collected data support this proposition. Settlement patterns consisted of multiple dispersed camps attached to residential bases occupied recurrently. Horizontal excavations from a residential base revealed structures and features analogous to pastoralist landscapes documented around the world. Faunal identification confirmed the preponderance of domesticated camelids. Based on this evidence, I argue that we need better explanatory frameworks for approaching the origins, organization, and variability associated with early food producing societies such as mobile camelid pastoralists.

The European conquest of the New World produced major socio-environmental reorganization in the Americas, but for many specific regions and ecosystems, we still do not understand how these changes occurred within a broader temporal framework. In this paper, we reconstruct the long-term environmental and vegetation changes experienced by high-altitude wetlands of the southcentral Andes over the last two millennia. Pollen and charcoal analyses of a 5.5-m-long core recovered from the semi-arid puna of northern Chile indicate that while climatic drivers influenced vegetation turnaround, human land use and management strategies significantly affected long-term changes. Our results indicate that the puna vegetation mostly dominated by grasslands and some peatland taxa stabilized during the late Holocene, xerophytic shrubs expanded during extremely dry events, and peatland vegetation persisted in relation to landscape-scale management strategies by Andean pastoralist societies. Environmental changes produced during the post-conquest period included the introduction of exotic taxa, such as clovers, associated with the translocation of exotic herding animals (sheep, cattle, and donkeys) and a deterioration in the management of highland wetlands.

Se presentan datos de avistamientos del Mirlo de Agua de Barba Roja (Cinclus schulzi) en la Cordillera de Sama, departamento de Tarija, Bolivia. Se recorrieron 17 quebradas, arroyos y ríos, pero solamente se realizaron 12 avistamientos en 4 cursos de agua, correspondientes a un mínimo de 10 individuos: 4 parejas, un individuo solitario y un volantón. Los mirlos fueron registrados en cursos de aguas claras, pero estaban ausentes en las porciones de los ríos contaminados con residuos de ganado. Se confirma la presencia de Cinclus schulzi en la Reserva Biológica Cordillera de Sama y su nidificación en el área. Además, se presentan datos sobre el comportamiento de alimentación y la interacción con otras especies. We present sighting data of the Rufous-throated Dipper (Cinclus schulzi) in Cordillera de Sama, Tarija Department, Bolivia. We visited 17 rivers and streams, but we attained only 12 sightings in 4 water courses, corresponding to a minimum of 10 individuals: 4 pairs, a solitary individual and a fledging. Dippers were recorded in clear water courses, but were absent in sites contaminated with livestock waste. We confirm the presence of Cinclus schulzi in the Cordillera de Sama Biological Reserve and its nesting in the area. Furthermore, we present data about foraging behaviour and interactions with other species.

Los cambios producidos en los sistemas de subsistencia de caza-recolección al cultivo de plantas y crianza de camélidos constituyen una de las transiciones más interesantes en la arqueología del altiplano andino. En este reporte se presentan resultados preliminares del análisis de patrones de asentamiento y materiales líticos recuperados en la región de Iroco, el margen noreste del Lago Uru-Uru, en el altiplano central de Bolivia. Los cambios producidos en los sistemas de asentamiento entre el período Arcaico (10.000-3.500 a.p.) y el período Formativo (3.500-1.600 a.p.) están relacionados con cambios en la organización económica y patrones de movilidad. Sin embargo, los cambios tecnológicos se encuentran enmarcados en una posible tradición de utilización de recursos y procesos de manufactura aplicados a los materiales líticos.

Increasing elevation can restrict the expansion of tree species by negatively affecting growth. In this study, we estimated growth velocity and evaluated the effects of extreme elevation on radial growth of the Andean tree Polylepis tarapacana Philippi (Rosaceae). We also developed different models to predict the relationship between age (number of tree-rings) and allometric characters (total height and diameter). Samples of trees and shrubs were collected between 4,200 and 4,600 m asl and analyzed using standard dendrochronological methods. Results evidenced that P. tarapacana is a slow-growing species since it grows less than 5 mm per year. Furthermore, elevation has a negative effect on radial growth. Morphometric models showed that a positive relationship between total height and diameter exists but not a significant relation between number of tree-rings and morphometry. Elevation had a major role in the radial growth of P. tarapacana which interacts with microclimatic conditions. Careful considerations should be made at the moment of using allometry as a surrogate for age in ecological studies.

El estudio de la tecnologia litica en los Andes se inicio con la identificacion tipologica de puntas de proyectil para definir secuencias cronologico-culturales de sociedades de cazadores recolectores. Analisis tecno-tipologicos como el que se presenta en este trabajo, tratan de mostrar que las morfologias de instrumentos liticos no son estaticas pues varian de acuerdo a su uso, mantenimiento y reciclaje. En este estudio, exploramos y caracterizamos la variabilidad morfologica del instrumental litico del sitio Ipilla 2, un campamento abierto del Arcaico Temprano (9.670-9.541 cal. a.p.), ubicado en los Andes de Arica (3.400 msm), norte de Chile. Los resultados sugieren que los instrumentos fueron intensamente mantenidos para extender su vida util, lo que altero los disenos originales. Otro proceso tecnologico incluyo la manufactura secuencial de distintos filos en un mismo instrumento. Estos resultados aportan a la comprension de los modos de vida de las sociedades de cazadores recolectores andinos y muestran que, metodologicamente, las formas tipologicas deben considerarse desde una perspectiva dinamica para convertirse en una herramienta analitica mas eficaz.

Se presenta un estudio de caso acerca de la ocupación Inka en la región periférica del Tawantinsuyu conocida como Señorío Kallawaya. Específicamente, se concentra en la descripción de las características del asentamiento de Maukallajta en las cercanías de Camata así como de otros sitios menores, ubicados en el extremo oriental de la región Kallawaya (bosques de yungas). Se exponen hipótesis de trabajo utilizando diversas líneas de evidencia (fuentes etnohistóricas, tradición oral, análisis arquitectónico y de artefactos), para explicar las múltiples razones que motivaron esta ocupación. Se concluye que la importante infraestructura física construida por los Inka en esta región fue motivada por una estrategia política económica imperial territorial que enfatizó la extracción de recursos (oro, coca y otros) hallados en esta zona fronteriza y de ingreso hacia las tierras bajas. La ocupación Inka igualmente estuvo acompañada por una fuerte ideología de dominación hegemónica

El estudio de las plantas psicotrópicas en las culturas de los Andes recibió considerable atención, especialmente en lo referente a la importancia de su uso como parte de ceremonias y rituales en diversas sociedades andinas. Sin embargo, muy pocos consideran la importancia de éstas y otros productos como parte esencial de relaciones de intercambio entre estas sociedades. El artículo analiza el consumo de dos especies de plantas psicotrópicas (Anadenanthera colubrina y Nicotiana tabacum), a partir de datos previos en los que el uso de estas especies han sido ampliamente documentadas. Se infiere sobre las relaciones de interacción que el uso y tráfico de estos bienes pudo promover en la región de valles del altiplano Sur Andino, permitiendo fortalecer vínculos generados a nivel de proveedores, intermediarios y consumidores, con la participación activa de las sociedades que ocuparon la región The study of psychotropic plants in Andean cultures has received considerable attention, especially the topics regarding the importance of its use as part of ceremonies and rituals that were held in different Andean societies. Nevertheless, very few of them consider the importance of this plants and other goods as essential parts of the exchange relationships. We infer that in the interregional interaction relationships the use and traffic of two psychotropic plants, such as the Anadenanthera colubrina and Nicotiana tabacum, strengthen the links between suppliers, intermediaries and consumers

The relations between humans and animals extend into socio-cultural aspects that go beyond the mere acquisition of food, meaning that animals constitute cultural resources that fulfill diverse roles in social and cultural systems. Visual images in different media, including rock art, represent one of the ways in which these complex relationships take place. While in the New World few comparative analyses of archaeofaunal and visual data have been addressed, in the Old World these studies have been framed by a dichotomist view between drawn (thought) and consumed (eaten) understanding, both terms as separate and disconnected social realms. This view also structures an abstract, non-pragmatic, rather passive, world drawn in art, against a concrete, practical, active world of consumption. The analysis we present here, based on principles of substantive economy theory, explores the relation between humans and animals in the prehistory of the Atacama Desert (ca. 13,000–410 BP), by comparing visual images of fauna depicted in rock art (engravings and paintings) with archaeofaunal remains from domestic and funerary contexts. The dataset (comprised of 1534 archaeofaunal items and 729 rock art animal motifs from 117 sites) was standardized by calculating the percentage of ubiquity of each animal item per period of time, using Spearman’s rank correlation coefficients to identify synchronic and diachronic changes in the relative importance of certain animals consumed. We observed important temporal and contextual variations in the consumption of animals drawn in rock art in the Atacama Desert, and we conclude that they reflect a selection of a wide range of ritual and utilitarian, but not mutually exclusive, functions. In particular, images of camelids emphasized the importance of providing fiber for the creation of textile artifacts and camelid use as pack animals in the caravan trade, both activities that were fundamental in the economy of local societies.

Se presentan los resultados del análisis zooarqueológico de dos conjuntos de artefactos Tiwanaku (400-1100 DC), procedentes de la localidad de Amaguaya, en Bolivia. Los conjuntos se componen de una importante cantidad de artefactos orgánicos (estuches, bolsas de cuero, textiles y fibras de lana). Mediante el análisis microscópico de pelos y fibras provenientes de los artefactos y su comparación con muestras de colecciones de referencia, se logró la identificación de la totalidad de las muestras estudiadas. Se determinó que, con excepción del jaguar (Phantera onca), el resto de las pieles y fibras con que fueron elaborados los artefactos pertenecen a especies de distribución local. Los conjuntos de Amaguaya proporcionan importante información acerca del ritual en Tiwanaku así como de las relaciones de intercambio e interacción generadas con la región de la Cordillera Oriental durante el Horizonte MedioIn this article I present the results of the zooarchaeological analysis of two archaeological sets of Tiwanaku (AD 400-1100) artifacts from Amaguaya, Bolivia. These sets are formed by an important quantity of organic elements (e.g. cases and leather bags, textiles and wool fibers). The identification of the entirety of the studied samples was achieved through the microscopic analysis of the hairs and fibers of the archaeological samples and their comparison with samples derived from a reference faunal collection. Excluding the cases that were made with jaguar leather (Phantera onca),the rest of the artifacts were elaborated with skins and fibers of animal species with a local distribution. The Amaguaya sets provide important information about the relationships of exchange and interaction between Tiwanaku and the eastern cordilleran region of the Andes during the Middle Horizon