Natalia Villavicencio ● Profesora Asistente

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]PROPOSAL ABSTRACT: Traditional archaeology proposes that the first settlers of South America moved preferentially along the Andes or the Pacific coast. Given that the Andean Puna (>3,000 masl) was an outstanding ecological megapatch that concentrated similar resources throughout the Andes, it was an attractive migratory route. This paved the way for the establishment of a unique Altiplano socio-ecological system, which later became the cradle of more complex cultural developments. Stable resources, temperate climate and relatively easy movements along the coastline has made the Pacific coast an even stronger candidate to explain early human dispersal and the construction of long-term cultural niche. In contrast, the Intermediate Depression in the hyperarid core of the Atacama Desert, between the Pacific coast and the Andes has not been perceived as a sufficiently productive enough ecosystem to support early human settling and dispersion. Theoretically, it has been assumed that it was used as an area of complementary resources for both coastal and Andean hunter-gatherer societies. In this proposal, we expect to show that this traditional view is incorrect and propose that the Intermediate Depression was not just an area of complementary resources and a barrier for human dispersal. On the contrary, we aim to provide new data showing how this region facilitated local settling and the expansion of H. sapiens into different ecosystems of South America, as it acted as an interglacial ecological refuge. Moreover, we propose that, despite an almost complete lack of rainfall, the Pampa del Tamarugal (PdT) was a much more productive and complex ecosystem during the Pleistocene-Holocene transition than today. Well-dated early residential areas, along with certain geomorphological and hydroclimatic features such as high watertable, mild temperatures and relatively warm winters generated extensive and diverse wetlands, creating some enclaves of the PdT very attractive compared to other regions. One of our main goals is to find these places, and ecologically and culturally characterize them. Conversely, we will investigate the potential of this basin as a glacial refuge a self-contained ecosystem that harbored many species of plants and animals that today occur at higher elevations, and uniquely suited to sustain small populations of hunter-gatherers that moved into the region, who then adopted and transformed this environment into their home. In this context, this proposal aims to research and understand how human societies developed long-term residential systems in a former ecological refuge withing this hyperarid desert. By describing and analyzing the dynamically productive environmental conditions of the PdT, we will address three major research problems: (a) the development of long-term residential systems, which gave rise to a conspicuous Intermediate Depression or pampa socio-ecological system, (b) the emergence of the PdT as a glacial refuge during the last glacial-interglacial transition; and (c) the coevolution and interdependence of the natural and cultural systems that ended with the disappearance of the pampa socio-ecological system and concomitant sequential extinction and extirpation of its biodiversity. The corollary of this process was that at the beginning of the Holocene, when the availability of water became insufficient, an exodus took place that must have had profound consequences for these groups, who had to abandon this landscape that they co-created for almost 2,000 years. Consequently, unlike the Andes or the Pacific coast, this early socio-ecological system did not continue into the Holocene. The lack of high quality and publicly available archaeological, paleoecological and paleontological datasets has weakened the general theoretical debate on early human migrations, settlement and the development of local socio-ecological systems. Here, we conceive human societies as part of the natural ecosystems on which they depend for their subsistence using a socio-ecological approach to analyze and understand the relationship and mutual influence between humans and what we consider nature today. This does not mean that early hunter-gatherers did not exploit or overexploit natural resources, but that they viewed them as social beings and heavily sanction overexploitation when it occurs or try to avoid it, for example through the implementation of taboos. Our project proposes the novel hypothesis that the Intermediate Depression offered sufficient conditions and resources for the development of a residential system and a unique pampa cultural tradition. Our view contrasts with the idea that the settlement pattern of the terminal Pleistocene hunter-gatherers would have been highly mobile and short-lived. The second novelty of this research is the composite methodology, that integrates different disciplinary methods such as: stable isotope analyses including Sr (to search for regional human mobility); paleogenomics to improve the resolution of morphological bone and plant taxa determination; geochronological dating, involving OSL and U/Th techniques to expand our chronologies; and technomorphological characterization of lithic, bone, wooden and textile artifacts, through complete chaîne opératoire methodology, pedological studies for soil horizon description. In sum, our major goal is to understand a different migration route and settlement system for the early peopling of the western slope of the Andes, by defining and explaining the characteristics of the residential systems developed in the PdT during the Pleistocene-Holocene transition, and the local ecologies associated to them. Our data will contribute towards resolving an old problem: the colonization of South America through the study of what is likely one of the best preserved and mostly unaltered sets of early American sites in all South America.[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

Conservation paleobiology deals with the use and application of paleontological data to the conservation of biodiversity. It implies the study of the circumstances driving species to the brink of extinction, to go extinct, or survive through the changes. In the present scenario of Global Change, this discipline seems useful as it can inform about the paths that species can undergo at present and in the near future. Particularly important to inform the state and faith of present-day ecosystems are those studies dealing with the last glacial-interglacial transition, since they show the changes faced by many still extant species under a scenario of global warming and an increasing human population. A close parallel to today’s threats to biodiversity. The present proposal will use the rich vertebrate fossil record from the site of Tagua Tagua 3 (TT3) in the Antiguo Lago de Tagua Tagua (ALTT), Region de O’Higgins, to investigate changes in biological communities through time. This record spans from the late Pleistocene (~13 kyr BP) to the mid Holocene (~6 kyr BP), presenting a continuous faunal sequence with extinct megafauna in its older component and extant vertebrates towards the Holocene. The record also attests the arrival and establishment of humans, as well as the occurrence of important changes in vegetation and climate. All this together makes of TT3 a unique record for central Chile, that offers the opportunity to make an adequate reconstruction of the recent past of a greatly endangered natural system. The ecosystem-through-time reconstruction and analysis includes the following objectives: (1) a comprehensive study of the fossil record to identify what, how many, and how abundant were the different species at different moments through time in the ALTT, with a particular emphasis on vertebrates; (2) to see how the communities reconstructed from the fossil record behave in moments of major environmental changes, including anthropogenic drivers of change, extinction of megafauna, and vegetation changes; (3) use food web modeling for analyzing the causes and consequences of the changes in these communities. This aims to pursue models that can integrate the fossil record and proxies of environmental change to understand the vulnerabilities to which these communities were exposed at different moments through time; (4) work in characterizing the present-day state of the vertebrate community in the area near the ALTT, aiming to build a modern picture in terms of community composition as well as in food web structure, to compare with what is revealed, and predicted, by the fossil record and associated models. The methodology to accomplishing these objectives includes: (1) fossil preparation, taxonomic identification, and quantification (MNI, NISP) for each level excavated in TT3; (2) to compare the faunal communities inferred from the fossil record to the available record of environmental changes through time (vegetation, climate, human arrival); (3) to stablish trophic relationships among the different species identified in the fossil record (using literature, stable isotope analyses results and zooarchaeological studies); this information will be used to implement food web models that explore the stability and complexity of different vertebrate communities through time and during times of particular important changes such as megafaunal extinctions, human arrival a changes in vegetation; (4) current species occurrences in the area will be inferred from the literature, open databases (GBIF) and complemented using species distributions models along with field species surveys; this information will be used to understand the current species composition of the area and to model current trophic interactions to compare with the ones inferred from the fossil record. Some expected results are a thorough characterization of community composition and food web topology through time, particularly at moments of important environmental changes. The arrival of humans during the late Pleistocene and the trophic connections generated with the fauna present should have an effect in the topology and stability of the food web. At the same time, the inclusion of a dynamic bottom-up controlled change (forested vs. shrubland) will provide important insights on how the food web and the vertebrate communities changed in moments of major vegetation changes. It is expected that some moments in the past will parallel the present-day conditions of biological systems from central Chile, providing clues on how to face the current environmental changes that endanger these ecosystems.

Proyecto que buscaba indagar en la realcion entre los primeros pobladores del desierto de atacama y su entorno a finales del Pleistoceno (12.000 años atrás).

Objetivos: Caso de estudio continental 1) Caracterizar y reconocer las áreas de mayor biodiversidad de megafauna extinta (mamíferos de >44 kg de masa corporal) para el periodo de transición Pleistoceno-Holoceno en Sudamérica. 2) Identificar si dichas áreas corresponden a posibles corredores o rutas utilizadas por los primeros cazadores-recolectores que colonizaron el continente durante el Pleistoceno tardío. Caso de estudio particular: Desierto de Atacama 3) Caracterizar la distribución de especies de megafauna para para el Desierto de Atacama (y para los Andes Centrales), tomando en cuenta el rico registro paleoclimático de la región como variable explicativa de la presencia de ciertas especies de megafauna en este sector. 4) Analizar si dicha distribución podría explicar el uso por parte de los primeros humanos de distintas rutas de migración en el sector (costeras, alto andinas y a través del desierto). Metodología: Generar Modelos de Distribución de Especies a nivel continental para los distintos taxa de megafauna extinta sudamericana que existieron durante la transición Pleistoceno-Holoceno. Estos modelos se generarán utilizando la locación geográfica e información cronológica del rico registro fósil de megafauna existente para Sudamérica, junto con información de las condiciones ambientales extraída de modelos climáticos generados para distintos momentos de la transición Pleistoceno-Holoceno. A partir de los Modelos de Distribución de Especies se identificarán las áreas de mayor biodiversidad (aquellas con la mayor cantidad de taxa) las cuales se comprarán con la distribución geográfica de sitios arqueológicos tempranos. Todo esto con la finalidad de identificar posibles rutas de migración humana hacia el continente. Para el caso del Desierto de Atacama (y de los Andes centrales) se aplicará la misma metodología descrita anteriormente pero haciendo uso del rico registro paleclimático existente para la región. Además, utilizaré los modelos para estimar la distribución pasada de especies actuales que habitan el sector desde el Pleistoceno tardío. Los Modelos de Distribución de Especies resultantes se compraran con la distribución geográfica de sitios arqueológicos para intentar reconocer las rutas migratorias usadas por los primeros humanos que colonizaban este ambiente extremo. Con la idea de obtener mayor información acerca de la megafauna extinta que habitó el Desierto de Atacama, me uniré a un grupo de investigadores en labores de rescate y análisis de sitios fósiles recientemente encontrados. Mi propósito es aportar con mi conocimiento de datación de megafauna extinta por radiocarbono y obtener más datos que mejoren la calidad de los modelos planeados. Resultados esperados: Se espera que la superposición de los modelos de distribución de megafauna extinta para la transición Pleistoceno-Holoceno muestre las áreas que probablemente exhibían la mayor biodiversidad para este periodo. Al comprar dichas áreas con la locación geográfica de los sitios tempranos de colonización humana en Sudamérica, se espera reconocer si las rutas de migración escogidas por los primeros cazadores-recolectores habrían sido determinadas por la presencia de mayor o menor biodiversidad de megafauna. Para el caso del Desierto de Atacama y los Andes Centrales, se espera obtener la probable distribución de las especies de megafauna que habitaban el área de manera más detallada, dado el uso de registros paleoclimáticos específicos para la zona como variables predictivas. Se espera que dichos Modelos de Distribución de Especies de megafauna permitan comprender e identificar la elección de rutas migratorias por los primeros cazadores-recolectores que habitaron estas regiones en particular.