My group's research centers on understanding how terrestrial landscapes and organisms respond to past climate change. We primarily use stable isotopic records to study interactions between mammals, vegetation, and climate in past ecosystems. Our work involves a combination of geologic fieldwork, isotopic lab work, and modern analog studies. Active projects include reconstructing Plio-Pleistocene environments from sedimentary and isotopic records preserved in the East African Rift system, isotope hydrology in Ethiopia, paleoecological and sedimentology of mid-Pleistocene sites in South Africa, and mass-dependent Δ17O variation in the sedimentary record and the hydrosphere. Much of the work is focused in Africa though we have active research projects in the U.S. (studying triple oxygen isotope variation in precipitation and surface waters) and in Peru (studying the climate history of a high elevation lake using triple oxygen isotopes).  Keywords: ecosystem and landscape responses to climate change; triple oxygen isotope geochemistry; plant-animal-climate interactions; isotope hydrology; isotope ecology; mammalian diets; environmental context for human evolution; paleoclimate proxy development; rift basin evolution; Eastern Africa; isotopic indicators of aridity and water stress.