Estructura demográfica, estilo de vida y relaciones biológicas de cazadores recolectores en un ambiente de desierto: Sitio Chenque I (Parque Nacional Lihué Calel, provincia de La Pampa, Argentina)

Abstract

The aim of this bioarchaeological investigation is to discuss the information obtained about the hunter-gatherer demographic structure, way of living and biological relations of the prehispanic societies that inhabited the Western Pampas (Argentina) during the Late Holocene. Human remains from three archaeological sites (Chenque I site, site 3 and La Lomita site from Tapera Moreira Locality) were analyzed. The investigations concentrate in the first of them, which contains two different stratigraphic units. The Superior Unit contains thousand of skeletal and dental remains with different degrees of fragmentation, comminglement, arrangement and anatomic association. In the Inferior Unit, 43 burial structures were detected, many of them associated with subsurface stone arrangements. A rigorous methodological procedure was taken in order to maximize the bioarchaeological information obtained from the analysis of the fragmented and removed rests, so they could be included into the global investigation carried out with the burials. The data generated in this manner indicate that if those kinds of samples are not included in the analyses, the reliability of the results obtained is significantly diminished. The whole simple was divided in two subsamples (A y B). The first included all the dental and bony elements from Chenque I site, complete or fragmented, that couldn’t be assigned to a particular skeleton and analyzed using a traditional bioarchaeological approximation. Subsample B included the burials recovered from the three mentioned archaeological sites. This subsample was analyzed in order to obtain information about sex and age using a traditional methodology. The first step was to evaluate the size and composition of subsample A, in order to know if complete or incomplete burials were buried in this site. Some measures of taxonomical and relative abundance were considered (NISP, MNE, MAU, MAU% and IF). Secondly, the metric and non-metric information obtained through the analysis of Subsample B were compared, so that the reliable methods to estimate age and to determine sex were identified, and then used in Subsample A. It could be stated that skeleton of both sexes and all ages were buried in the site. Minimum Number of Individuals (MNI) was estimated, taking into account variables as the amount of teeth and bones segments identified, laterality, sex, age and size. The final estimation indicated that at least 216 individuals were buried in the site. Then, a demographic curve was obtained and compared with other hunter-gatherer profiles. It could be stated that the general shape is similar to other attritional demographic curves, but some particular aspects were identified in the Chenque I site, which indicate some particular aspects of its demographic dynamics. The metabolic and functional stress from Subsample A was also included in this investigation. In order to evaluate the general levels of health and use of the body, the degree of prevalence of the metabolic (porotic hyperostosis, cribra orbitalia, and enamel hypoplasias and hypocalcifications) and functional (osteoartritis and entesoexostoses) stress from Subsample A were analyzed. Finally, a preliminary study using dental metrics was developed to contribute to a previous proposal that stressed that al least two different populations buried in Chenque I site. The data obtained in this investigation is complementary to models developed to interpret de prehispanic dynamics in Western Pampas, but some special aspects were identified for the first time, defining a process of demographic pressure during Late Holocene. This bioarchaeological data, complemented with other archaeological information previously known, and with many chronicles from Pampa and Patagonia regions, led propose a process that link this demographic pressure with the presence of battle episodes, the preference of male children, and female infanticide.