NOAA/WDS Paleoclimatology - Combined NGRIP-Cariaco Basin 56,000 Year d18O Record

The mechanisms of Late Pleistocene megafauna extinctions remain fiercely contested, with human impact or climate change cited as principal drivers. Here, we compare ancient DNA and radiocarbon data from 31 detailed time series of regional megafaunal extinctions/replacements over the past 56,000 years with standard and new combined records of Northern Hemisphere climate in the Late Pleistocene. Unexpectedly, rapid climate changes associated with interstadial warming events are strongly associated with the regional replacement/extinction of major genetic clades or species of megafauna. The presence of many cryptic biotic transitions prior to the Pleistocene/Holocene boundary revealed by ancient DNA confirms the importance of climate change in megafaunal population extinctions and suggests that metapopulation structures necessary to survive such repeated and rapid climatic shifts were susceptible to human impacts.