Hominin Ecology of the Early Oldowan 2 Ma

Environmental change is key for human evolution, especially at times of anatomical and behavioral change in life histories, such as the origin of meat consumption, economic diversification, and dispersal. However, for the earliest phase of human evolution featuring the technology-dependent hominins that shaped our lineage since 2.6 Ma, the Oldowan, there is a dearth of archaeological evidence directly associated with rich chronostratigraphic and environmental datasets amenable to tracking ecological change and adaptation to new physiographic conditions. One place where this type of information has been recently retrieved is the Western Plio-Pleistocene rift basin of Olduvai Gorge (now Oldupai), Tanzania. We explore habitat range by Oldowan-bearing hominins amidst extremely diverse ecosystems throughout a stratified sequence 235 ka-long, thus predating by >180 ka the earliest landmark fossil hominins and classic Oldowan from the Eastern side of the basin. Our study provides multi-proxy evidence of environmental adaptability, demonstrating colonisation of fresh volcanic landscapes and occupation of fast-changing biomes by 2 Ma.