Search

Rapid environmental change is a catalyst for human evolution, driving dietary innovations, habitat diversification, and dispersal. However, there is a dearth of information to assess hominin adaptions to changing physiography during key evolutionary stages such as the early Pleistocene. Here we report a multiproxy dataset from Ewass Oldupa, in the Western Plio-Pleistocene rift basin of Olduvai Gorge (now Oldupai), Tanzania, to address this lacuna and offer an ecological perspective on human adaptability two million years ago. Oldupai’s earliest hominins sequentially inhabited the floodplains of sinuous channels, then river-influenced contexts, which now comprises the oldest palaeolake setting documented regionally. Early Oldowan tools reveal a homogenous technology to utilise diverse, rapidly changing environments that ranged from fern meadows to woodland mosaics, naturally burned landscapes, to lakeside woodland/palm groves as well as hyper-xeric steppes. Hominins periodically used emerging landscapes and disturbance biomes multiple times over 235,000 years, thus predating by more than 180,000 years the earliest known hominins and Oldowan industries from the Eastern side of the basin., Oldupai Gorge, Tanzania is a key site for understanding early human evolution. Here, the authors report a multiproxy dataset from the Western basin of Oldupai Gorge dating to 2 million years ago, enabling the in situ comparison of lithic assemblages, paleoenvironments and hominin behavioral adaptability.

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.

The African Early Stone Age record, including that of Oldupai Gorge, reveals widespread evidence for hominin exploitation of quartzose lithic raw materials such as quartzite. However, few studies have sought to characterize these rock types grounded on the assumption that they are not amenable for provenance studies. Through the use of macroscopic, petrographic, and EDXRF analysis, we characterize source material from five quartzitic outcrops belonging to the Mozambique Belt adjacent to Oldupai Gorge. Our results show that certain macroscopic varieties strictly occur at some outcrops while petrographic analyses – which will be strengthened by a greater sample size – reveal that accessory minerals may be outcrop-specific. Statistical analyses of the geochemical data through linear correlations, Kruskal-Wallis tests, PCA, and DFA show that there are inter- and intra-outcrop differences, and elemental concentrations specific of certain outcrops. This multi-scalar approach provides a reproducible classificatory framework for additional characterization studies and archaeological testing at Oldupai to shed light on hominin palaeoenvironmental exploitation and palaeoecological behavior.