Luis Alberto Borrero

Early Patagonian Hunter-Gatherers: Subsistence and Technology

The process of the initial human exploration and colonization of Fuego-Patagonia was probably one of a slow filling in of empty spaces. The available information, coming mostly from caves and rockshelters, is sufficient to initiate a discussion on the subsistence and technology of the early Patagonian hunter-gatherers. All the evidence points toward a generalized diet. Opportunistic use of Pleistocene mammals, together with a more systematic use of guanaco, is indicated. A redundant pattern of association of artifacts with ground sloth, horse, and guanaco is evident. Lithic artifacts were routinely and expediently made on rocks available in the immediate vicinity, with an emphasis on the transport of bifacial artifacts and/or preforms, adequate for situations of high mobility. Local raw material was used predominately. Human populations were living at low densities, and space, as well as other resources, was probably abundant in relation to human needs. Density-independent adaptations are thus indicated. Under these conditions, no major need for niche differentiation existed, and it is not necessary to postulate specialized use of parts of the ecosystem.

The Pleistocene—Holocene Transition in Southern South America

This chapter explores some of the data and models relevant for an understanding of human adaptations during the Pleistocene—Holocene transition in southern South America, between approximately 13,000 BP and 8,000 bp.

Synergistic roles of climate warming and human occupation in Patagonian megafaunal extinctions during the Last Deglaciation

Patagonian megafaunal extinctions reveal synergistic roles of climate change and human impacts. The causes of Late Pleistocene megafaunal extinctions (60,000 to 11,650 years ago, hereafter 60 to 11.65 ka) remain contentious, with major phases coinciding with both human arrival and climate change around the world. The Americas provide a unique opportunity to disentangle these factors as human colonization took place over a narrow time frame (~15 to 14.6 ka) but during contrasting temperature trends across each continent. Unfortunately, limited data sets in South America have so far precluded detailed comparison. We analyze genetic and radiocarbon data from 89 and 71 Patagonian megafaunal bones, respectively, more than doubling the high-quality Pleistocene megafaunal radiocarbon data sets from the region. We identify a narrow megafaunal extinction phase 12,280 ± 110 years ago, some 1 to 3 thousand years after initial human presence in the area. Although humans arrived immediately prior to a cold phase, the Antarctic Cold Reversal stadial, megafaunal extinctions did not occur until the stadial finished and the subsequent warming phase commenced some 1 to 3 thousand years later. The increased resolution provided by the Patagonian material reveals that the sequence of climate and extinction events in North and South America were temporally inverted, but in both cases, megafaunal extinctions did not occur until human presence and climate warming coincided. Overall, metapopulation processes involving subpopulation connectivity on a continental scale appear to have been critical for megafaunal species survival of both climate change and human impacts.

Concentraciomes de pilas de rocas en la cuenca superior del río Santa Cruz (Argentina)

Este trabajo presenta y caracteriza dos concentraciones de pilas de rocas identificadas en la margen sudoeste de la cuenca superior del rio Santa Cruz (Argentina), en la Estancia Bon Accord. La edad minima de estas estructuras es estimada a partir de analisis liquenometricos. Se recopila informacion sobre la existencia de este tipo de estructuras en la region patagonica. Por ultimo, se discuten algunas de las funciones hipoteticas de estas acumulaciones utilizando casos arqueologicos locales y de otras partes del mundo.

Changes in the Technological Organization and Human Use of Space in Southern Patagonia (Argentina) During the Late Holocene

This paper documents technological and behavioral changes in the southern part of the Upper Santa Cruz River Basin during the Late Holocene and examines possible relationships with environmental changes. The findings suggest an important relationship between human use of space and long-term trends in precipitation. This relationship is emphasized by the inverse correlation between precipitation near the Andes and that in the steppe further east.

Nuevos datos para la discusión arqueológica de corredores en el bosque del suroeste de la provincia de Santa Cruz, Argentina: El caso del arroyo Los Loros

Fil: Carballo Marina, Flavia Elena. Universidad Nacional de la Patagonia Austral; Argentina