Late Pleistocene to Holocene human palaeoecology in the tropical environments of coastal eastern Africa

Abstract

The ecological adaptations that stimulated the dispersal and technological strategies of our species during the Late Pleistocene remain hotly disputed, with some influential theories focusing on grassland biomes or marine resources as key drivers behind the rapid expansion and material culture innovations of Homo sapiens within and beyond Africa. Here, we present novel chronologically resolved, zooarchaeological taxonomic and taphonomic analysis, and stable isotope analysis of human and faunal tooth enamel, from the site of Panga ya Saidi (c. 78–0.4 ka), Kenya. Zooarchaeological data provide rare insights into the fauna associated with, and utilized by, Late Pleistocene-Holocene human populations in tropical coastal eastern Africa. Combined zooarchaeological and faunal stable isotope data provide some of the only dated, ‘on-site’ archives of palaeoenvironments beyond the arid interior of eastern Africa for this time period, while stable isotope analysis of humans provides direct snapshots of the dietary reliance of foragers at the site. Results demonstrate that humans consistently utilized tropical forest and grassland biomes throughout the period of site occupation, through a transition from Middle Stone Age to Later Stone Age technological industries and the arrival of agriculture in the region. By contrast, while coastal resources were obtained for use in symbolic material culture, there is limited evidence for consumption of marine resources until the Holocene. We argue that the ecotonal or heterogeneous environments of coastal eastern Africa may have represented an important refugium for populations during the increasing climatic variability of the Late Pleistocene and Holocene, and that tropical environments were one of a diverse series of ecosystems exploited by H. sapiens in Africa at the dawn of global migrations.