Clocking the arrival of Homo sapiens into the Southern Cone of South America

POLITIS, G.; PRATES, L.

Tübingen

Simposio; Annual Symposium on New Perspectives on the Peopling of Americas; 2016

The Southern Cone of SouthAmerica (Argentina, Chile, Uruguay and South ?eastern Brazil) was the lastcontinental mass  colonized by humans.  Until recently, the discussion about the peoplingof the Americas revolved around the Clovis First- Pre-Clovis  debate. Nowadays, the axis of this debate has changed  (it has been consistently proved  that there were people in the Americas beforeClovis)  and  the central debate is  if humans were  South of  the Laurentide/Cordilleran Ice Sheet  after or before  the onset of deglaciation (ca. 18  to 19 ky) of  the-Last Glacial  Maximum (LGM-) .  However, while several models have beenproposed to uphold the first hypothesis, the second one is supported byisolated site reports and sparse data  .With very few exceptions (i. e. Bradly and Stanford 2012) no coherent models havebeen proposed  to integrate the few suggested pre ?LGM sites sprawled in the continent .In this scenario, a fine-grainstudy of the timing  of the arrivaland  the spatial  occupation sequences of the expansion processis significant to understand the pattern of colonization of Homo sapiens in  the Americas.  In this paper,  we will summarize and discuss the evidence from some key sites in the SouthernCone with pre-and post LGM ages. We will also present a compilation of theearliest 14C dates as a proxy ( though imperfect) of human presence in the Southern Cone, both from samples(charcoal, faunal remains etc) associated with human presence as well from humanskeletons. Based on the graphics  produced by this data base and employing themethod of Marshall (1997) along with the algorithm proposed by Saltré andcollaborators (2015) (which provides a 95% confidence band around the estimatedtime of peopling), we will  analyze themain chronological  trends and spatial  sequences in the region. Finally, we willcontrast our results from the Southern Cone with the new - continental scale - modelsof peopling of the Americas, based on ancient DNA.