During the Late Pleistocene, over about 50,000 years, most megafauna outside of Africa went extinct.
Old hypotheis: megafauna went extinct due to rapid cooling events.
More recent hypothesis: megafauna went extinct due to human migration into the megafauna's ecosystems.
New hypothesis: megafauna went extinct due to rapid warming events.
The study, published in Science on Thursday, is the first to link specific climatic events to localized extinctions of megafauna. In this case, the events are called “interstadials,” or short warming periods that occurred throughout the era. The interstadials saw temperature increases anywhere from 4 to 16˚C, the study’s authors explain, and sometimes that warming occurred over just a few decades. Once warming occurred, the Earth would stay warm for hundreds, sometimes thousands, of years.
[Alan Cooper of the University of Adelaide] Cooper’s model suggests that climate-driven extinction events happened in a pattern over time, closely tied to warming events that occurred through the era, going back until at least 50,000 years ago. Those patterns, Cooper said, weren’t always discernible from the fossil record. Instead, the team used a combination of DNA and radiocarbon dating to link localized megafauna extinctions to a series of rapid warming events over time.The article ends with obligatory tie-in to global warming.
Article: Abrupt warming events drove Late Pleistocene Holarctic megafaunal turnover
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.