Although climate change is considered to have been a large-scale driver of African human evolution, landscape-scale shifts in ecological resources that may have shaped novel hominin adaptations are rarely investigated. We use well-dated, high-resolution, drill-core datasets to understand ecological dynamics associated with a major adaptive transition in the archeological record ∼24 km from the coring site. Outcrops preserve evidence of the replacement of Acheulean by Middle Stone Age (MSA) technological, cognitive, and social innovations between 500 and 300 thousand years (ka) ago, contemporaneous with large-scale taxonomic and adaptive turnover in mammal herbivores. Beginning ∼400 ka ago, tectonic, hydrological, and ecological changes combined to disrupt a relatively stable resource base, prompting fluctuations of increasing magnitude in freshwater availability, grassland communities, and woody plant cover. Interaction of these factors offers a resource-oriented hypothesis for the evolutionary success of MSA adaptations, which likely contributed to the ecological flexibility typical of Homo sapiens foragers. Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).
Peter Buck Fund for Human Origins Research (Smithsonian), William H. Donner Foundation (R.P.), the Ruth and Vernon Taylor Foundation (R.P.), Whitney and Betty MacMillan (R.P.), National Science Foundation grants EAR 1322017 (A.L.D.) and EAR 1349599 (D.D.), Swiss National Science Foundation grant P300P2 158501 (M.S.), Hong Kong Research Grants Council (R.B.O. and V.M.), and the Smithsonian Human Origins Program (R.P.). Funding support for A.N. and K.B.S. provided by NSF awards EAR-1338322 and EAR-1462297.
Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).