Revealing Environments of Hominin Origins (REHO): Applying Novel Enamel Isotope Analysis to the Late Miocene of Eastern Africa

REHO combines cutting-edge methodological development with the generation of new seasonality records from ~7.5-6 Ma to reconstruct climate, vegetation and environmental changes at spatiotemporal scales most relevant to characterizing the palaeoenvironmental context of hominin origins. The Late Miocene ~7.5-6 Ma interval captures the emergence of the earliest hominins broadly, and at the study site of Lothagam, Kenya, specifically. REHO aims to tackle a critical, long-standing issue in human evolutionary studies concerning the environments of the earliest hominins and the problems presented by the varied spatiotemporal scales spanned by existing palaeoenvironmental records. REHO will accomplish this through isotopic analysis of ‘serial’ enamel samples taken sequentially down the crown of fossil mammal teeth, which provide records of annual to subannual dietary and body water change in these taxa and, by extension, the environments occupied by the hominins associated with them. REHO aims to collect serial enamel isotope data and develop new complex species-specific models of tooth growth that facilitate the extraction of seasonality signals from these isotope data. The three objectives of the project are to: (1) provide evidence of seasonal vegetation change via serial sampling of hypsodont herbivores at Lothagam, (2) provide evidence of seasonal moisture and precipitation change through serial sampling of fossil papionin monkeys using Secondary Ion Mass Spectroscopy (SIMS), and the generation of tooth growth models based on synchrotron micro-CT histological data and (3) provide a comparative framework of seasonality patterns from the last 10 million years in the Turkana Basin, Kenya, by serial sampling fossil impala. The researcher will develop methods at the cutting-edge of isotope analysis, pairing this with enhanced skills in fieldwork and faunal analysis, which will set her apart from others in fields related to human evolution, archaeology and palaeobiology.