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- Large Carnivore Footprints from the Late Pleistocene of ArgentinaUI.ADSABS.HARVARD.EDU
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0 Tags 0 Acciones - DriveDrive or The Drive may refer to: Motoring Driving, the act of controlling a vehicle Road trip, a journey on roadsRoadways Roadways called "drives" may include: Driveway, a private road for local access to structures, abbreviated "drive" Road, an identifiable thoroughfare, route, way, or path between two placesScience Drive theory, a diverse set of motivational theories in psychology Drive reduction theory (learning theory), a theory of learning and motivation Prey drive, in the study of animal behavior, the predictable tendency of a carnivore to pursue and capture prey Gene drive, in genetics, a type of bias in the inheritance of a geneArts, entertainment, and media Films Drive (1997 film), an action film starring Mark Dacascos Drive (2002 film), a Japanese film starring Ren Osugi...EN.WIKIPEDIA.ORG
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340 Tags 0 Acciones - Genome-wide Evidence Reveals that African and Eurasian Golden Jackals Are Distinct SpeciesSummary. The golden jackal of Africa (Canis aureus) has long been considered a conspecific of jackals distributed throughout Eurasia, with the nearest source populations in the Middle East. However, two recent reports found that mitochondrial haplotypes of some African golden jackals aligned more closely to gray wolves (Canis lupus) [1, 2], which is surprising given the absence of gray wolves in Africa and the phenotypic divergence between the two species. Moreover, these results imply the existence of a previously unrecognized phylogenetically distinct species despite a long history of taxonomic work on African canids. To test the distinct-species hypothesis and understand the evolutionary history that would account for this puzzling result, we analyzed extensive genomic data including mitochondrial genome sequences, sequences from 20 autosomal loci (17 introns and 3 exon segments), microsatellite loci, X- and Y-linked zinc-finger protein gene (ZFX and ZFY) sequences, and whole-genome nuclear sequences in African and Eurasian golden jackals and gray wolves. Our results provide consistent and robust evidence that populations of golden jackals from Africa and Eurasia represent distinct monophyletic lineages separated for more than one million years, sufficient to merit formal recognition as different species: C. anthus (African golden wolf) and C. aureus (Eurasian golden jackal). Using morphologic data, we demonstrate a striking morphologic similarity between East African and Eurasian golden jackals, suggesting parallelism, which may have misled taxonomists and likely reflects uniquely intense interspecific competition in the East African carnivore guild. Our study shows how ecology can confound taxonomy if interspecific competition constrains size diversification.UI.ADSABS.HARVARD.EDU
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35 Tags 0 Acciones - Ancient DNA suggests modern wolves trace their origin to a Late Pleistocene expansion from BeringiaGrey wolves (Canis lupus) are one of the few large terrestrial carnivores that have maintained a wide geographical distribution across the Northern Hemisphere throughout the Pleistocene and Holocene. Recent genetic studies have suggested that, despite this continuous presence, major demographic changes occurred in wolf populations between the Late Pleistocene and early Holocene, and that extant wolves trace their ancestry to a single Late Pleistocene population. Both the geographical origin of this ancestral population and how it became widespread remain unknown. Here, we used a spatially and temporally explicit modelling framework to analyse a data set of 90 modern and 45 ancient mitochondrial wolf genomes from across the Northern Hemisphere, spanning the last 50,000 years. Our results suggest that contemporary wolf populations trace their ancestry to an expansion from Beringia at the end of the Last Glacial Maximum, and that this process was most likely driven by Late Pleistocene ecological fluctuations that occurred across the Northern Hemisphere. This study provides direct ancient genetic evidence that long-range migration has played an important role in the population history of a large carnivore, and provides insight into how wolves survived the wave of megafaunal extinctions at the end of the last glaciation. Moreover, because Late Pleistocene grey wolves were the likely source from which all modern dogs trace their origins, the demographic history described in this study has fundamental implications for understanding the geographical origin of the dog.see also the Perspective by Rena M. Schweizer and Robert K. Wayne.UI.ADSABS.HARVARD.EDU
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42 Tags 0 Acciones - Warring brothers: The complex interactions between wolves (Canis lupus) and dogs (Canis familiaris) in a conservation contextAlthough both wolves and dogs have been the subjects of numerous studies in many disciplines, the complex relationships between them have not yet been synthesized within a common review, and neither has it been placed in a holistic conservation context. Information and data are spread across numerous publications from different disciplines that rarely interact. Dogs have become the most common carnivore and their population is still increasing. In a context of wolf recovery in multi-use landscapes, there is a growing concern among conservationists for the potential negative impact of dogs on wolf conservation. With this paper we aim to review the numerous and complex interactions existing between wolves and dogs, using literature from disciplines as diverse as history, archeology, anthropology, genetics, ecology, and epidemiology in order to better understand the wolf-dog relationship and its potential impact on wolf conservation. Starting with their phylogenetic relationship and following a summary of the current knowledge on the dog's ancestry we explore how dogs can represent a direct threat for wolves through hybridization, disease transfer and competition. The review highlights a number of ways in which dogs can impact wolf conservation, although a general lack of data and conclusive studies is a common theme that emerges for many topics. Then we analyse how dogs can mitigate human-wolf conflicts through their role as livestock guardians or wolf hunters. Finally we describe the complex phenomenon of wolf predation on dogs before discussing the wolf-dog relationships in general, with a special focus on including a more anthropological perspective. The review highlights the diversity of interactions between wolves and dogs, that can be both negative and positive for wolf conservation. However, more important than these direct impacts, the review highlights how the wolf-dog relationship challenges human attempts to construct simple dichotomies between wild and domestic, or between nature and culture. The borders between these concepts are in fact much more fluid and elusive than is often appreciated, and wolf conservation must adapt to this more complex reality.UI.ADSABS.HARVARD.EDU
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63 Tags 0 Acciones - a Possible Smilodon (mammalia, Felidae) Coprolite from the Pleistocene of ArgentinaPleistocene large carnivores from the Pampean Region have been studied almost always based on bone remains. Here we report the first coprolite of a large carnivore from the Late Pleistocene of the Pampean Region, Argentina. The coprolite was found associated with megafauna bone remains and it shows the typical shape and size of a carnivorous mammal, with a length of 240 mm and a maximum diameter of 39.59 mm. The coprolite contains two bones of the autopodium of an artiodactyl, and numerous dermal ossicles of giant terrestrial sloths. The coprolite's composition, size, and shape allow us to discard ursids, canids, and small felids. Ursid and canid feces contain abundant plant remains, which are absent in the coprolite described here. Feces of extant felids are smaller than the coprolite here as they do not exceed 130 mm in length and 30 mm in diameter. Based on size, shape, and bone inclusions, the discovered coprolite may be attributed to the Machairodontinae saber-toothed felid Smilodon. If correctly identified, this coprolite sheds light on predatory habits of Smilodon.UI.ADSABS.HARVARD.EDU
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0 Tags 0 Acciones - Iterative evolution of hypercarnivory in canids (Mammalia: Carnivora): evolutionary interactions among sympatric predatorsConvergent evolution of hypercarnivorous adaptations in canids has occurred a number of times in the last 40 m.y. among distantly related taxa. The adaptations include an increase in carnassial blade length, reduction or loss of post-carnassial molars, and transformation of the talonid of the lower first molar from a basinlike depression into a trenchant, bladelike cusp. Although the diversity of these specialized canids is typically low in past and present communities, it was unusually high during the Late Oligocene of North America and the Pleistocene of South America. These two comparable events provide an opportunity for exploring possible causes of the evolution of hypercarnivory in canids. Plots of generic diversity against time for North American predators reveal a roughly inverse relationship between the number of hypercarnivorous canid taxa and the numbers of other hypercarnivores, such as creodonts, nimravids, mustelids, and amphicyonids. Similarly, the radiation of hypercarnivorous canids in South America occurred at a time of relatively low diversity of other hypercarnivores. Analysis of trophic diversity within the North American carnivore paleoguild before, during, and after the Late Oligocene reveals considerable taxonomic turnover among carnivores because of immigration and speciation. Late Oligocene hypercarnivorous canids appear to have been replaced first by amphicyonids and large mustelids, and then by felids.Despite the repeated tendency of canids to evolve adaptations for hypercarnivory, a canid has yet to appear that is completely catlike, that is, without any post-carnassial molars. This possible constraint on morphological evolution in canids is argued to have resulted, paradoxically, in increased flexibility over evolutionary time and a great potential for rapid diversification and clade survivorship. Finally, it is suggested that the iterative pattern of specialization of the lower molars for meat-slicing that is seen in all families of carnivores, past and present, is probably a result of intraspecific competition for food, perhaps among littermates. This intraspecific selective force is countered by competition among species, since there are limits on the number of sympatric hypercarnivorous species within a single community.UI.ADSABS.HARVARD.EDU
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0 Tags 0 Acciones - Distinct Predatory Behaviors in Scimitar- and Dirk-Toothed Sabertooth CatsSummary. Over the Cenozoic, large cat-like forms have convergently evolved into specialized killers of "megaherbivores" that relied on their large, and laterally compressed (saber-like) canines to rapidly subdue their prey [1-5]. Scimitar- and dirk-toothed sabertooths are distinct ecomorphs that differ in canine tooth length, degree of serration, and postcranial features indicative of dissimilar predatory behavior [6-13]. Despite these differences, it is assumed that they used a similar "canine-shear" bite to kill their prey [14, 15]. We investigated the killing behavior of the scimitar-toothed Homotherium serum and the dirk-toothed Smilodon fatalis using a comparative sample of living carnivores and a new quantitative approach to the analysis of skull function. For the first time, we quantified differences in the relative amount and distribution of cortical and trabecular bone in coronal sections of skulls to assess relative skull stiffness and flexibility [16-19]. We also use finite element analysis to simulate various killing scenarios that load skulls in ways that likely favor distinct proportions of cortical versus trabecular bone across the skull. Our data reveal that S. fatalis had an extremely thick skull and relatively little trabecular bone, consistent with a large investment in cranial strength for a stabbing canine-shear bite. However, H. serum had more trabecular bone and most likely deployed an unusual predatory behavior more similar to the clamp-and-hold technique of the lion than S. fatalis. These data broaden the killing repertoire of sabertooths and highlight the degree of ecological specialization among members of the large carnivore guild during the Late Pleistocene of North America.UI.ADSABS.HARVARD.EDU
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A carnivore is an organism that primarily eats other animals for sustenance. Examples of carnivores include lions, tigers, wolves, and sharks.By: ChatGPT AI0 Acciones