Plant Wax Biomarker Evidence for Late Pleistocene-to-Holocene Forest Resilience and Ecological Refugium Dynamics at Panga ya Saidi, Coastal Kenya

The role of environmental refugia in human evolutionary ecology is unclear due to a lack of correlated high-resolution datasets linking climate and environmental change with human behavior. Panga ya Saidi, coastal Kenya, is one of the few sites in eastern Africa that has both on-site climate and vegetation proxy archives and an archaeological assemblage that documents the Middle-to-Later Stone Age transition. Here, we present a 57,000-year plant wax biomarker record from Panga ya Saidi’s archaeological sediments and evaluate the site’s potential as an ecological refugium. Compound specific plant wax carbon (δ13C) and hydrogen (δ2H) isotope data indicate long-term ecological stability and a C3-dominated ecosystem since at least Marine Isotope Stage (MIS) 3. Despite arid phases, including a hyper-arid Last Glacial Maximum, the tropical moist broadleaf forest biome at Panga ya Saidi persisted through these perturbations, giving humans the ability to access forest, grassland, and coastal habitats via mobile foraging and social networking. The ecological contrasts between the coastal forest mosaic and surrounding ecoregions likely played a role in deep-time technological developments, with habitat variability and ecological diversity being conducive to cultural innovations regardless of climatic perturbations.