Climate changes, human peopling and regional differentiation during late Holocene in Patagonia.

Abstract The main aim of this paper is to evaluate if certain processes that were documented in a specific area of Central-Southern Patagonia during the Late Holocene were also registered in a broader spatial scale. Previous investigations carried out in our study area located in Central-Western Santa Cruz province, Patagonia, have stated that climatic fluctuations during the Late Holocene (last 2500 years) were the cause of a reduction of hunter-gatherers' residential mobility. The new climatic conditions were characterized by important environmental droughts, which increased during the Mediaeval Climatic Anomaly, circa 900 years BP. This reduction in mobility resulted in concentrations of populations in low altitude basins and increased logistical and seasonal mobility, defined as a process of extensification. In this paper we take a broad spatial perspective to evaluate to what extent the low residential mobility identified in our research area had a correlation in a larger regional scale. Also we assess if this lead to a regional differentiation among hunter-gatherer populations, previous to European contact (450 years BP). In order to achieve these aims, we undertake a coarse grain analysis, using available data published on the composition and distribution of the archaeological record for Central-Southern Patagonia, an area of about 450.000 km2. Specifically, we consider evidence about technology, zooarchaeology, rock art, mortuary record and paleodietary studies. The analysis indicates that a reduced residential mobility could have occurred in certain areas of the study region, linked to the aforementioned climatic changes. On the issue of regional differentiation, the archaeological record highlights the complexity of this process. There are a variety of arguments both for and against the idea of a process of regionalization in Central-Southern Patagonia in the Late Holocene. We propose a process of differentiation of populations with low residential mobility which nonetheless remained connected through the circulation of goods, information and people. [ABSTRACT FROM AUTHOR]