Myrian Álvarez

Quantifying use-wear traces through RIMAPS and Variogram analyses

The aim of this paper is to present the results obtained through the application of two imaging methods named rotated image with maximum average power spectrum (RIMAPS) and Variograms to mathematically characterize distinct patterns of worked materials on used edges of lithic artifacts. Both analytical procedures were performed on digitized images taken with an electronic microscope, allowing for the quantitative description of a given surface and revealing its topographic patterns. The preliminary research conducted on a sample of experimental lithic artifacts used to process different materials has shown promising results to the extent that fingerprints of different work processes (hide, bone, and wood-working) can be drawn.

Effect of Resource Spatial Correlation and Hunter-Fisher-Gatherer Mobility on Social Cooperation in Tierra del Fuego

This article presents an agent-based model designed to explore the development of cooperation in hunter-fisher-gatherer societies that face a dilemma of sharing an unpredictable resource that is randomly distributed in space. The model is a stylised abstraction of the Yamana society, which inhabited the channels and islands of the southernmost part of Tierra del Fuego (Argentina-Chile). According to ethnographic sources, the Yamana developed cooperative behaviour supported by an indirect reciprocity mechanism: whenever someone found an extraordinary confluence of resources, such as a beached whale, they would use smoke signals to announce their find, bringing people together to share food and exchange different types of social capital. The model provides insight on how the spatial concentration of beachings and agents’ movements in the space can influence cooperation. We conclude that the emergence of informal and dynamic communities that operate as a vigilance network preserves cooperation and makes defection very costly.

Análisis arqueobotánico de piezas de madera del extremo austral americano

La preservacion de arcos y astiles en el registro arqueologico patagonico es sumamente escasa. No obstante, para el caso concreto de Tierra del Fuego la informacion etnografica muestra un amplio uso de vegetales para la manufactura de este tipo de armas. A fin de superar el sesgo entre ambos registros, hemos llevado a cabo el analisis arqueobotanico y morfo-metricos de una coleccion de arcos y fechas del Museo del Fin del Mundo (Ushuaia, Argentina). El objetivo principal es generar informacion sobre las caracteristicas del sistema de arco y fecha utilizados por los las sociedades cazadoras-recolectoras que habitaron la isla y determinar las etapas necesarias para la obtencion y procesado del material lenoso. Los resultados obtenidos revelaron la explotacion de materias primas hasta ahora desconocidas en la region.

PRÁCTICAS MORTUORIAS ENTRE LOS CAZADORES-RECOLECTORES DEL CANAL BEAGLE: EL CASO DE SHAMAKUSH ENTIERRO

During the last years, the archaeological research of mortuary record on the Magellan- Fuegian Archipielago has increased. These studies showed that mortuary practices implied a great diversity of behaviors in connection with body treatment, burial placement, number of individuals or artifacts left by the mourners with the bodies. In this paper we focus on the analysis of a specifi c context, Shamakush burial, located on the northern coast of the Beagle Channel region. This site, dated on 620 ± 60 BP, exhibit the more elabo- rate and complex mortuary context due to the labor invested on the arrangement of the body and to the

Emergence and Evolution of Cooperation Under Resource Pressure

We study the influence that resource availability has on cooperation in the context of hunter-gatherer societies. This paper proposes a model based on archaeological and ethnographic research on resource stress episodes, which exposes three different cooperative regimes according to the relationship between resource availability in the environment and population size. The most interesting regime represents moderate survival stress in which individuals coordinate in an evolutionary way to increase the probabilities of survival and reduce the risk of failing to meet the minimum needs for survival. Populations self-organise in an indirect reciprocity system in which the norm that emerges is to share the part of the resource that is not strictly necessary for survival, thereby collectively lowering the chances of starving. Our findings shed further light on the emergence and evolution of cooperation in hunter-gatherer societies.

An Ethnoarchaeological Study on Anthropic Markers from a Shell-midden in Tierra del Fuego (Southern Argentina): Lanashuaia II

ABSTRACT For many years the identification of activity areas has been carried out through the spatial distribution of lithics, zooarchaeological remains and specific features such as fireplaces. However, these data are rarely combined and integrated with results from specific analytical techniques such as phytoliths, organic matter, carbonates and multielemental analysis. This research presents the first results of an intrasite spatial analysis on a layer from the site Lanashuaia II, a shell-midden located on the Beagle Channel coast (Tierra del Fuego, Argentina). Ethnoarchaeology is used as a methodological tool to give content to the concept of anthropic markers by means of formulating archaeological hypothesis on the basis of ethnological information. This paper presents the application of specific anthropic markers, which have been designed and applied to identify ashy remains and waste areas through different combinations of proxies. The results show how an approach that integrates different techniques enhances data interpretation and allows to give visibility to activities that may not leave visible evidences.

The use of shells as tools by hunters-gatherers in the Beagle Channel (Tierra del Fuego, South America): an ethnoarchaeological experiment

This paper presents the results of the analysis of lipid residues extracted from two Aulacomya atra shells and a single Mytilus edulis shell found in the hunter-fisher-gatherer site of Lanashuaia II, a shell midden located on the Beagle Channel (Tierra del Fuego, Argentina). According to existing ethnographic information, the shells could have been used as receptacles (like spoons) or knives by the Yamana people that inhabited the region in the historical period (nineteenth and twentieth centuries). Yamana society is the final moment of a long history of hunter-fisher-gatherer societies present in the Beagle Channel and the rest of Fuegian Channels and islands. Higher concentrations of lipid residues were recovered from both A. atra shells than from the sedimentary control sample analyzed. This is consistent with existing accounts that these types of shells were used as containers to cook or melt fat-rich foods. The composition of lipids extracted from archaeological shell was significantly different from the degraded reference cooking residues prepared from modern A. atra shells.

TALLANDO DESDE LO ALTO: UN SITIO DE EXPLOTACIÓN DE MATERIALES LÍTICOS DE LOS GRUPOS CAZADORES-RECOLECTORES DE LA ISLA GRANDE DE TIERRA DEL FUEGO

This paper provides the initial results obtained from the analysis of a lithic workshop, named Altos del Varela I, located on the top of Petersen hill in Tierra del Fuego Island (Argentina). The site contains distinctive areas entirely composed of a high frequency of flmade from local metamorphic rhyolite. These results open the debate about the use of mountain landscape between the fuegian hunter-gatherers as well as the interaction between coastal and inland groups.

Hunter–gatherer mobility and technological landscapes in southernmost South America: a statistical learning approach

The present work aims to quantitatively explore and understand the relationship between mobility types (nautical versus pedestrian), specific technological traits and shared technological knowledge in pedestrian hunter–gatherer and nautical hunter–fisher–gatherer societies from the southernmost portion of South America. To that end, advanced statistical learning techniques are used: state-of-the-art classification algorithms and variable importance analyses. Results show a strong relationship between technological knowledge, traits and mobility types. Occupations can be accurately classified into nautical and pedestrian due to the existence of a non-trivial pattern between mobility and a relatively small fraction of variables from some specific technological categories. Cases where the best-fitted classification algorithm fails to generalize are found significantly interesting. These instances can unveil lack of information, not enough entries in the training set, singular features or ambiguity, the latter case being a possible indicator of the interaction between nautical and pedestrian societies.