Synergistic roles of climate warming and human occupation in patagonian megafaunal extinctions during the Last Deglaciation
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Date
2016-06-17
Journal Title
Journal ISSN
Volume Title
Publisher
American Association for the Advancement of Science
Abstract
The causes of Late Pleistocene megafaunal extinctions (60,000 to 11,650 years ago, hereafter 60 to 11.65 ka) remain
contentious, with major phases coinciding with both human arrival and climate change around the world. The
Americas provide a unique opportunity to disentangle these factors as human colonization took place over a
narrow timeframe (~15 to 14.6 ka) but during contrasting temperature trends across each continent. Unfortunately,
limited data sets in South America have so far precluded detailed comparison. We analyze genetic and radiocarbon
data from 89 and 71 Patagonian megafaunal bones, respectively, more than doubling the high-quality Pleistocene
megafaunal radiocarbon data sets from the region.Weidentify anarrowmegafaunal extinction phase 12,280 ± 110 years
ago, some 1 to 3 thousand years after initial human presence in the area. Although humans arrived immediately
prior to a cold phase, the Antarctic Cold Reversal stadial, megafaunal extinctions did not occur until the stadial
finished and the subsequent warming phase commenced some 1 to 3 thousand years later. The increased resolution
provided by the Patagonianmaterial reveals that the sequence of climate andextinctionevents inNorthandSouth
America were temporally inverted, but in both cases, megafaunal extinctions did not occur until human presence and
climate warming coincided. Overall, metapopulation processes involving subpopulation connectivity on a continental
scale appear to have been critical for megafaunal species survival of both climate change and human impacts.
Description
Keywords
Ciencia, Extinciones megafaunales, Antarctic Cold Reversal stadial, Pleistoceno tardío
Citation
Sci. Adv. 2016; 2 : e1501682 17 June 2016