Lithic technological responses to Late Pleistocene glacial cycling at Pinnacle Point Site 5-6, South Africa

Jayne Wilkins; Kyle S Brown; Simen Oestmo; Telmo Pereira; Kathryn L Ranhorn; Benjamin J Schoville; Curtis W Marean

doi:10.1371/journal.pone.0174051

Lithic technological responses to Late Pleistocene glacial cycling at Pinnacle Point Site 5-6, South Africa

PLoS One. 2017 Mar 29;12(3):e0174051. doi: 10.1371/journal.pone.0174051. eCollection 2017.

Authors

Jayne Wilkins^{1

2}, Kyle S Brown¹, Simen Oestmo³, Telmo Pereira⁴, Kathryn L Ranhorn⁵, Benjamin J Schoville^{1

3}, Curtis W Marean^{2

3}

Affiliations

¹ Human Evolution Research Institute, Department of Archaeology, University of Cape Town, Rondebosch, Private Bag, South Africa.
² Centre for Coastal Paleoscience, Nelson Mandela Metropolitan University, Port Elizabeth, Eastern Cape, South Africa.
³ Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, United States of America.
⁴ Interdisciplinary Center for Archaeology and Evolution of Human Behavior, Faculdade das Ciências Humanas e Sociais, Universidade do Algarve, Campus Gambelas, Faro, Portugal.
⁵ Center for the Advanced Study of Human Paleobiology, George Washington University, Washington, DC, United States of America.

Abstract

There are multiple hypotheses for human responses to glacial cycling in the Late Pleistocene, including changes in population size, interconnectedness, and mobility. Lithic technological analysis informs us of human responses to environmental change because lithic assemblage characteristics are a reflection of raw material transport, reduction, and discard behaviors that depend on hunter-gatherer social and economic decisions. Pinnacle Point Site 5-6 (PP5-6), Western Cape, South Africa is an ideal locality for examining the influence of glacial cycling on early modern human behaviors because it preserves a long sequence spanning marine isotope stages (MIS) 5, 4, and 3 and is associated with robust records of paleoenvironmental change. The analysis presented here addresses the question, what, if any, lithic assemblage traits at PP5-6 represent changing behavioral responses to the MIS 5-4-3 interglacial-glacial cycle? It statistically evaluates changes in 93 traits with no a priori assumptions about which traits may significantly associate with MIS. In contrast to other studies that claim that there is little relationship between broad-scale patterns of climate change and lithic technology, we identified the following characteristics that are associated with MIS 4: increased use of quartz, increased evidence for outcrop sources of quartzite and silcrete, increased evidence for earlier stages of reduction in silcrete, evidence for increased flaking efficiency in all raw material types, and changes in tool types and function for silcrete. Based on these results, we suggest that foragers responded to MIS 4 glacial environmental conditions at PP5-6 with increased population or group sizes, 'place provisioning', longer and/or more intense site occupations, and decreased residential mobility. Several other traits, including silcrete frequency, do not exhibit an association with MIS. Backed pieces, once they appear in the PP5-6 record during MIS 4, persist through MIS 3. Changing paleoenvironments explain some, but not all temporal technological variability at PP5-6.

Publication types

Historical Article

MeSH terms

Archaeology*
Climate
Diet, Paleolithic / history
Geologic Sediments / analysis*
History, Ancient
Humans
Ice Cover
Paleontology*
Population Dynamics*
South Africa

Grants and funding

Funding was provided by the Social Science and Humanities Research Council of Canada (JW), NORAM and The American-Scandinavian Foundation (SO), Fundação para a Ciência e Tecnologia SFRH/BPD/73598/2010 (TP), IGERT DGE 0801634 (KLR), the Hyde Family Foundations, Institute of Human Origins, and the National Science Foundation BCS-9912465, BCS-0130713, BCS-0524087, BCS-1138073 (CWM). Marean recognizes the support of a grant from the John Templeton Foundation to the Institute of Human Origins at Arizona State University. The opinions expressed in this publication are those of the author(s) and do not necessarily reflect the views of the John Templeton Foundation or any other granting agency. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.