Hominin evolution and aridity

Based on oxygen isotopes from modern and fossil mammalian herbivore tooth enamel, estimates of water deficits associated with hominin archaeological and fossil records in eastern Africa indicate that, during the Pliocene and Pleistocene, climate was highly variable, and long-term aridification was unlikely to have been associated with the expansion of grasses and grazing herbivores, a transformation thought to be a driver of human evolution.

Article #17-00597: “Aridity and hominin environments,” by Scott A. Blumenthal et al.