Global late Quaternary megafauna extinctions linked to humans, not climate change

Abstract

The late Quaternary megafauna extinction was a severe global-scale event. Two factors, climate change and modern humans, have received broad support as the primary drivers, but their absolute and relative importance remains controversial. To date, focus has been on the extinction chronology of individual or small groups of species, specific geographical regions or macroscale studies at very coarse geographical and taxonomic resolution, limiting the possibility of adequately testing the proposed hypotheses. We present, to our knowledge, the first global analysis of this extinction based on comprehensive country-level data on the geographical distribution of all large mammal species (more than or equal to 10 kg) that have gone globally or continentally extinct between the beginning of the Last Interglacial at 132 000 years BP and the late Holocene 1000 years BP, testing the relative roles played by glacial–interglacial climate change and humans. We show that the severity of extinction is strongly tied to hominin palaeobiogeography, with at most a weak, Eurasia-specific link to climate change. This first species-level macroscale analysis at relatively high geographical resolution provides strong support for modern humans as the primary driver of the worldwide megafauna losses during the late Quaternary.

Ecology in an anthropogenic biosphere

“…produced major ecological changes across Europe, Australasia, and the Americas by their hunting and trophic displacement of megafauna, causing regime shifts in ecosystem structure ( Fig. 3A; Barnosky 2008, Estes et al 2011, Doughty 2013, Gill 2014, Sandom et al 2014.…”

Late Quaternary sea-level history and the antiquity of mammoths (Mammuthus exilisandMammuthus columbi), Channel Islands National Park, California, USA

“…The possible causes of megafaunal extinction at the close of the Pleistocene have been hotly debated, and as the literature on this topic is voluminous, only a brief summary is given here. Three main mechanisms of extinction have been proposed for North America: (1) the human arrival hypothesis (Martin, 1967(Martin, , 1984(Martin, , 2005Haynes, 2013;Sandom et al, 2014, and references therein), wherein humans, newly arrived from Asia, extirpated an unwary North American fauna; (2) the climate change hypothesis, in which the shift from a glacial to an interglacial climate brought about extraordinary changes in ecosystems such that megafaunal species were unable to adapt (Graham and Lundelius, 1984;Meltzer, 2002, 2003 and references therein); and (3) the cosmic catastrophic event hypothesis, where an impact or airburst of an extraterrestrial body (comet or meteor) is thought to have brought about dramatic changes in climate, widespread fires, and demise of human (Clovis culture) and animal (megafauna) populations (Firestone et al, 2007;Kennett et al, 2008Kennett et al, , 2009). Other investigators have pointed out the possibility of a combination of human-caused and climate-related causes of extinction (see discussion in Barnosky et al, 2004).…”

Global nutrient transport in a world of giants

“…However, most ecosystems lost their large animals, with around 150 mammal megafaunal (here, defined as ≥44 kg of body mass) species going extinct in the late Pleistocene and early Holocene (1,2). These extinctions and range declines continued up through historical times and, in many cases, into the present (3).…”