Quaternary Extinctions and Their Link to Climate Change

Millennia before the modern biodiversity crisis—a worldwide event being driven by the multiple impacts of anthropogenic global change—a mass extinction of large-bodied fauna occurred. After a million years of severe climatic fluctuations, during which the earth waxed and waned between frigid ice ages and warm interglacials, with apparently few extinctions, hundreds of species of mammals, flightless birds, and reptiles suddenly went extinct over the course of the last 50,000 years (Barnosky, 2009). Due both to our intrinsic fascination with huge prehistoric beasts and to the possible insights these widespread species losses might lend to the modern extinction problem, the mystery of the “megafaunal” (large animal) extinctions have led to much theorizing, modeling, and digging (for their fossils or environmental proxies) over the last 150 years (Martin, 2005). The topic continues to invoke strong scientific interest (Koch and Barnosky, 2006; Grayson, 2007; Gillespie, 2008; Barnosky and Lindsey, 2010; Nogues-Bravo et al., 2010; Price et al., 2011).