On the association of giant short-faced bear ( Arctodus simus ) and brown bear ( Ursus arctos ) in late Pleistocene North America

Steffen, Martina; Fulton, Tara L.

doi:10.1016/j.geobios.2017.12.001

Cited by 13 publications

(18 citation statements)

References 77 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reappearance of lions and brown bears in Eastern Beringia during MIS 2 occurred at around the same time as the local extinction of Arctodus , which may relate to previously proposed competition between brown bears and Arctodus (Barnes et al, 2002; Steffen & Fulton, 2018). The apparent timing of the extinction of Arctodus in Eastern Beringia ~23 ka could be linked to the sharp climatic cooling associated with Heinrich Event 2 (24.3–23.3 ka bp ), a period characterized by drastic climatic changes caused by large discharges of ice into the North Atlantic following the collapse of the Northern Hemisphere ice sheets (Heinrich, 1988; Hemming, 2004).…”

Section: Discussionmentioning

confidence: 56%

Section: Discussionmentioning

confidence: 62%

“…The recolonizing populations were genetically distinct from those present in Eastern Beringia pre-MIS 2 as well as those south of the ice sheets, confirming that they probably comprised a new wave of dispersal from Western Beringia (Figure4e). This wave of megafaunal dispersals associated with the re-emergence of the Bering Land Bridge in MIS 2 may also have included early Native American human populations, who are recorded shortly afterwards in the stratigraphic record of Chiquihuite Cave in Mexico, from ~26 ka(Ardelean et al, 2020).The reappearance of lions and brown bears in Eastern Beringiaduring MIS 2 occurred at around the same time as the local extinction of Arctodus, which may relate to previously proposed competition between brown bears and Arctodus(Barnes et al, 2002;Steffen & Fulton, 2018). The apparent timing of the extinction of Arctodus in Eastern Beringia ~23 ka could be linked to the sharp climatic cooling associated with Heinrich Event 2 (24.3-23.3 ka bp), a period characterized by drastic climatic changes caused by large discharges of ice into the North Atlantic following the collapse of the…”

mentioning

confidence: 79%

See 2 more Smart Citations

Lions and brown bears colonized North America in multiple synchronous waves of dispersal across the Bering Land Bridge

et al. 2021

View full text Add to dashboard Cite

The Bering Land Bridge connecting North America and Eurasia was periodically exposed and inundated by oscillating sea levels during the Pleistocene glacial cycles. This land connection allowed the intermittent dispersal of animals, including humans, between Western Beringia (far north-east Asia) and Eastern Beringia (north-west North America), changing the faunal community composition of both continents. The Pleistocene glacial cycles also had profound impacts on temperature, precipitation, and vegetation, impacting faunal community structure and demography. While these paleoenvironmental impacts have been studied in many large herbivores from Beringia (e.g., bison, mammoths, horses), the Pleistocene population dynamics of the diverse guild of carnivorans present in the region are less well understood, due to their lower abundances. In this study, we analyze mitochondrial genome data from ancient brown bears (Ursus arctos; n = 103) and lions (Panthera spp.; n = 39), two megafaunal carnivorans that dispersed into North America during the Pleistocene. Our results reveal striking synchronicity in the population dynamics of Beringian lions and brown bears, with multiple waves of dispersal across the Bering Land Bridge coinciding with glacial periods of low sea levels, as well as synchronous local extinctions in Eastern Beringia during Marine Isotope Stage 3. The evolutionary histories of these two taxa underscore the crucial biogeographic role of the Bering Land Bridge in the distribution, turnover, and maintenance of megafaunal populations in North America.We would like to thank the following institutions for allowing access to specimens in their collections:

show abstract

Section: Discussionmentioning

confidence: 56%

Section: Discussionmentioning

confidence: 62%

mentioning

confidence: 79%

See 1 more Smart Citation

Lions and brown bears colonized North America in multiple synchronous waves of dispersal across the Bering Land Bridge

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Sea levels rose after this, and with a calibrated range of 16,713–17,296 cal ybp, our A. simus died at a time when the shortest distance between CCI and the mainland was ~ 8 km (today’s shortest distance is ~ 19 km 6 ). While extant bears are strong swimmers, A. simus is only known from one other insular locality, Vancouver Island, and it is rare there despite a largely continental fauna, represented by an isolated ulna in a glacial gravel pit 34 and another individual with multiple associated skeletal elements in a cave 54 .…”

Section: Discussionmentioning

confidence: 99%

Biogeographic problem-solving reveals the Late Pleistocene translocation of a short-faced bear to the California Channel Islands

Mychajliw

Rick

Dağtaş

et al. 2020

Sci Rep

View full text Add to dashboard Cite

An accurate understanding of biodiversity of the past is critical for contextualizing biodiversity patterns and trends in the present. Emerging techniques are refining our ability to decipher otherwise cryptic human-mediated species translocations across the Quaternary, yet these techniques are often used in isolation, rather than part of an interdisciplinary hypothesis-testing toolkit, limiting their scope and application. Here we illustrate the use of such an integrative approach and report the occurrence of North America’s largest terrestrial mammalian carnivore, the short-faced bear, Arctodus simus, from Daisy Cave (CA-SMI-261), an important early human occupation site on the California Channel Islands. We identified the specimen by corroborating morphological, protein, and mitogenomic lines of evidence, and evaluated the potential natural and anthropogenic mechanisms of its transport and deposition. While representing just a single specimen, our combination of techniques opened a window into the behavior of an enigmatic species, suggesting that A. simus was a wide-ranging scavenger utilizing terrestrial and marine carcasses. This discovery highlights the utility of bridging archaeological and paleontological datasets to disentangle complex biogeographic scenarios and reveal unexpected biodiversity for island systems worldwide.

show abstract

“…In Eurasia and North Africa, brown bears underwent multiple range expansions and contractions coinciding with climate events and eventually colonised western North America (Sommer & Benecke 2005). An omnivorous diet and generality in habitat association probably contributed to the ability of brown bears to outcompete Arctodus simus upon expansion from Beringia into North America (Steffen & Fulton 2018). The divergence of American black bears is estimated at 0.94 Ma (Kutschera et al 2014) in western North America, with eventual colonisation of eastern North America (Puckett et al 2015) as Arctodus spp.…”

Section: Evolutionary Timelinementioning

confidence: 99%

Denning, metabolic suppression, and the realisation of ecological opportunities in Ursidae

et al. 2021

View full text Add to dashboard Cite

Through realisation of ecological opportunities, populations and species can experience relaxed selection pressures, facilitating ecological release and leading to rapid speciation and morphological diversification. Behavioural plasticity in response to environmental change contributes to diversification by exposing individuals to novel conditions through their interactions with resources or dispersal to new areas. Despite strong theoretical support, demonstrations of this evolutionary process are rare. The family Ursidae is the product of one or more adaptive radiations following the Miocene–Pliocene transition. Denning behaviour associated with over‐winter seclusion, fasting, and parturition coinciding with seasonally decreased food availability appears to be paraphyletic in Ursidae phylogenies. However, female bears of all species undergo varying degrees of seclusion and fasting during parturition and early post‐natal care, which is not consistent with periods of seasonally decreased food availability. As denning behaviour is tightly linked to fitness through energetics and reproduction, these behaviours are suspected to be under strong selection. Mechanisms responsible for the observed variability among species, populations, and individuals have not been explored. In this review, we detail the evolutionary history of extinct and extant Ursidae regarding expression of denning behaviour and as a function of realised ecological opportunities. We compare behaviours across Ursidae and contextualise our results within extant species ecology. We demonstrate the role of relaxed extrinsic and intrinsic factors in the expression of metabolic suppression among Ursidae species, and across populations and reproductive groups, through the realisation of ecological opportunities. In doing so, we propose a more refined consideration of and perspective on this behaviour and provide a mechanism for the adaptive radiation in Ursidae.

show abstract

On the association of giant short-faced bear ( Arctodus simus ) and brown bear ( Ursus arctos ) in late Pleistocene North America

Cited by 13 publications

References 77 publications

Lions and brown bears colonized North America in multiple synchronous waves of dispersal across the Bering Land Bridge

Lions and brown bears colonized North America in multiple synchronous waves of dispersal across the Bering Land Bridge

Biogeographic problem-solving reveals the Late Pleistocene translocation of a short-faced bear to the California Channel Islands

Denning, metabolic suppression, and the realisation of ecological opportunities in Ursidae

Contact Info

Product

Resources

About