Test of Martin’s overkill hypothesis using radiocarbon dates on extinct megafauna

Surovell, Todd A.; Pelton, Spencer R.; Anderson-Sprecher, Richard; Myers, Adam D.

doi:10.1073/pnas.1504020112

Cited by 79 publications

(52 citation statements)

References 46 publications

(34 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…To account for taphonomic bias in reconstructions of the dynamics of past animal populations using frequency distributions of radiocarbon dates will require the development of taphonomic models specific to bone, and this study is a first attempt to do so. Understanding how bone is lost through time and across space is especially critical to studies of Quaternary extinctions that use radiocarbon databases to infer the causes of extinction [3][4][5]13]. Towards that end, we can say with some confidence that the global model of sedimentary loss can be applied to EB, and very likely to circumpolar regions in general, but not to CUSA and SA.…”

Section: Discussionmentioning

confidence: 99%

Spatio-temporal variation in the preservation of ancient faunal remains

Surovell

Pelton

2016

Biol. Lett.

Self Cite

View full text Add to dashboard Cite

Palaeodemographic studies of animals using frequency distributions of radiocarbon dates are increasingly used in studies of Quaternary extinction but are complicated by taphonomic bias, or the loss of material through time. Current taphonomic models are based on the temporal frequency distributions of sediments, but bone is potentially lost at greater rates because not all sedimentary contexts preserve bone. We test the hypotheses that (i) the loss of bone over time is greater than that of sediment and (ii) this rate of loss varies geographically at large scales. We compiled radiocarbon dates on Pleistocene-aged bone from eastern Beringia (EB), the contiguous United States (CUSA) and South America (SA), from which we developed models of taphonomic loss. We find that bone is lost at greater rates than terrestrial sediment in general, but only for CUSA and SA. Bone in EB is lost at approximately the same rate as terrestrial sediments, which demonstrates the excellent preservation environments of arctic regions, presumably due to preservative effects of permafrost. These differences between bone and sediment preservation as well as between arctic and non-arctic regions should be taken into account by any research addressing past faunal population dynamics based on temporal frequency distributions.

show abstract

Section: Discussionmentioning

confidence: 99%

Spatio-temporal variation in the preservation of ancient faunal remains

Surovell

Pelton

2016

Biol. Lett.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Two recent studies that take a global perspective find human arrival as the most likely and parsimonious explanation of the pattern and timing of extinctions (14,15). A new study (38) analyzes direct carbon dates for megafauna declines across the Americas, finding a north-to-south temporal decrease consistent with the dates for the first significant human presence. Furthermore, temporally detailed studies in North America have not found a close link to climate change (40,42).…”

Section: Megafauna Prehistorymentioning

confidence: 97%

“…The overall global pattern has been rapid loss in regions experiencing sudden arrival of H. sapiens (14,38), with no overall correlation with climatic variation. Approximately 1 billion individual large animals were lost from the Earth's land surface (39).…”

Section: Megafauna Prehistorymentioning

confidence: 99%

“…Although still much discussed, there is increasingly strong evidence for a causal link between megafaunal extinction and the arrival of H. sapiens (2,14,38,40). The predominant reason is that humans were effective and generalist superpredators that were able to hunt even the largest mammals that had previously faced little predation pressure.…”

Section: Megafauna Prehistorymentioning

confidence: 99%

See 1 more Smart Citation

Megafauna and ecosystem function from the Pleistocene to the Anthropocene

Malhi

Doughty

Galetti

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

407

382

View full text Add to dashboard Cite

Large herbivores and carnivores (the megafauna) have been in a state of decline and extinction since the Late Pleistocene, both on land and more recently in the oceans. Much has been written on the timing and causes of these declines, but only recently has scientific attention focused on the consequences of these declines for ecosystem function. Here, we review progress in our understanding of how megafauna affect ecosystem physical and trophic structure, species composition, biogeochemistry, and climate, drawing on special features of PNAS and Ecography that have been published as a result of an international workshop on this topic held in Oxford in 2014. Insights emerging from this work have consequences for our understanding of changes in biosphere function since the Late Pleistocene and of the functioning of contemporary ecosystems, as well as offering a rationale and framework for scientifically informed restoration of megafaunal function where possible and appropriate.For hundreds of millions of years, an abundance of large animals, the megafauna, was a prominent feature of the land and oceans. However, in the last few tens of thousands of years-a blink of an eye on many evolutionary and biogeochemical timescales-something dramatic happened to Earth's ecology; megafauna largely disappeared from vast areas, rendered either actually or functionally extinct (1, 2). Only in small parts of the world do megafauna exist at diversities anything close to their previous state, and, in many of these remaining regions, they are in a state of functional decline through population depletion and range contraction. In the oceans, a similar process has occurred over the last few hundred years: although there has been little absolute extinction, there has been a dramatic decline in the abundance of whales and large fish through overharvesting (3). Both on land and in oceans, declines continue today (4-7).Homo sapiens evolved and dispersed in a world teeming with giant creatures. Our earliest art forms, such as the haunting and mesmerizing Late Pleistocene cave paintings of Lascaux and Altamira, show that megafauna had a profound impact on the psyche and spirituality of our ancestors. To humans past and modern, they indicate resources, danger, power, and charisma, but, beyond these impacts, such large animals have profound and distinct effects on the nature and functioning of the ecosystems they inhabit.Martin (8) first posited a major human role in past megafaunal disappearances, and, since then, much has been written on their patterns and causes and the relative importance of human effects, climate change, and other factors (8)(9)(10)(11)(12)(13)(14)(15). Only recently has work begun to address the environmental consequences of this dramatic transition from a megafaunal to a nonmegafaunal world on Earth's ecology, as manifested through vegetation cover (16), plant-animal interactions (17), ecosystem structure (16, 18), trophic interactions (7), fire regimes (19), biogeochemical cycling (20), and climate (21,22).In this pap...

show abstract

“…An impact event (independently or in conjunction with YD cooling) is suggested to explain North American megafaunal extinctions (Firestone et al, 2007;Wolbach et al, 2018a, b), though recent research has built a compelling case that anthropogenic factors such as overhunting and disease were largely responsible for the demise of many species of large mammalian fauna (Sandom et al, 2014;Bartlett et al, 2016;van der Kaars et al, 2017;Cooper et al, 2015;Metcalf et al, 2016). Notably, megafaunal extinction dates appear correlated with the timing of human colonisation of the Western Hemisphere (Surovell et al, 2016), a result inconsistent with an impactdriven extinction. However, even if future research confirms that megafaunal extinctions were caused by human activity rather than a bolide impact, this does not reduce the YDIH's explanatory power as a YD trigger.…”

Section: Compatibility With Other Hypothesesmentioning

confidence: 99%

Evaluating the link between the sulfur-rich Laacher See volcanic eruption and the Younger Dryas climate anomaly

2018

View full text Add to dashboard Cite

Abstract. The Younger Dryas is considered the archetypal millennial-scale climate change event, and identifying its cause is fundamental for thoroughly understanding climate systematics during deglaciations. However, the mechanisms responsible for its initiation remain elusive, and both of the most researched triggers (a meltwater pulse or a bolide impact) are controversial. Here, we consider the problem from a different perspective and explore a hypothesis that Younger Dryas climate shifts were catalysed by the unusually sulfurrich 12.880 ± 0.040 ka BP eruption of the Laacher See volcano (Germany). We use the most recent chronology for the GISP2 ice core ion dataset from the Greenland ice sheet to identify a large volcanic sulfur spike coincident with both the Laacher See eruption and the onset of Younger Dryasrelated cooling in Greenland (i.e. the most recent abrupt Greenland millennial-scale cooling event, the Greenland Stadial 1, GS-1). Previously published lake sediment and stalagmite records confirm that the eruption's timing was indistinguishable from the onset of cooling across the North Atlantic but that it preceded westerly wind repositioning over central Europe by ∼ 200 years. We suggest that the initial short-lived volcanic sulfate aerosol cooling was amplified by ocean circulation shifts and/or sea ice expansion, gradually cooling the North Atlantic region and incrementally shifting the midlatitude westerlies to the south. The aerosol-related cooling probably only lasted 1-3 years, and the majority of Younger Dryas-related cooling may have been due to the seaice-ocean circulation positive feedback, which was particularly effective during the intermediate ice volume conditions characteristic of ∼ 13 ka BP. We conclude that the large and sulfur-rich Laacher See eruption should be considered a viable trigger for the Younger Dryas. However, future studies should prioritise climate modelling of high-latitude volcanism during deglacial boundary conditions in order to test the hypothesis proposed here.

show abstract

Test of Martin’s overkill hypothesis using radiocarbon dates on extinct megafauna

Cited by 79 publications

References 46 publications

Spatio-temporal variation in the preservation of ancient faunal remains

Spatio-temporal variation in the preservation of ancient faunal remains

Megafauna and ecosystem function from the Pleistocene to the Anthropocene

Evaluating the link between the sulfur-rich Laacher See volcanic eruption and the Younger Dryas climate anomaly

Contact Info

Product

Resources

About