Faunal Responses to Climate Change: Middle Pleistocene Through the Holocene

This presentation reviews the current state of knowledge concerning the responses of large mammal communities to climate change from the middle Pleistocene through the Holocene, with a focus on the African and Eurasian records. In southernmost Africa, an increasing number of well-dated fossil assemblages and paleoenvironmental records illustrate how glacial-interglacial cycling contributed to the reorganization of ungulate communities. Here, the cycling of species-rich communities dominated by large grazers to impoverished communities composed of small browsers has important implications for early human subsistence behavior and can be linked to behavioral innovation. Recent research on the middle and late Pleistocene faunas of East Africa suggests a trend toward increasing aridity over the last 660,000 years. This is consistent with climate records from elsewhere and may have played an important role in the dispersal of early humans from their presumed East African homeland. Increased moisture at the onset of the Holocene drove the extinction of the dominant large mammals and an essentially modern fauna emerged. In Eurasia, environmental change and the expansion and contraction of ice sheets during glacial and interglacial phases was a dominant force in large mammal biogeography. The periodic contraction of species to glacial refugia – core areas for the survival of temperate species during cool glacial phases – established a recurrent pattern of extinction and recolonization, with important implications for the demographic histories of hominin populations.