Suchergebnisse

[Background] The evolutionary relationships of Felidae during their Early-Middle Miocene radiation is contentious. Although the early common ancestors have been subsumed under the grade-group Pseudaelurus, this group is thought to be paraphyletic, including the early ancestors of both modern cats and extinct sabretooths. [Methods] Here, we sequenced a draft nuclear genome of Smilodon populator, dated to 13,182 ± 90 cal BP, making this the oldest palaeogenome from South America to date, a region known to be problematic for ancient DNA preservation. We analysed this genome, together with genomes from other extinct and extant cats to investigate their phylogenetic relationships. [Results] We confirm a deep divergence (~20.65 Ma) within sabre-toothed cats. Through the analysis of both simulated and empirical data, we show a lack of gene flow between Smilodon and contemporary Felidae. [Conclusions] Given that some species traditionally assigned to Pseudaelurus originated in the Early Miocene ~20 Ma, this indicates that some species of Pseudaelurus may be younger than the lineages they purportedly gave rise to, further supporting the hypothesis that Pseudaelurus was paraphyletic. ; This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No [681396]), (project Extinction Genomics). This project has also received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no. FP7-PEOPLE-2011-IEF-298820. The work was also supported by the Independent Research Fund Denmark | Natural Sciences, Forskningsprojekt 1, grant no. 8021-00218B to EDL.

With growing evidence of unsustainable use of the world's resources, such as hydrocarbon reserves, and related environmental pollution, as in alarming climate change predictions, sustainable development is arguably the prominent issue of the 21st century. This volume gives a wide ranging introduction focusing on the arid Gulf region, where the challenges of sustainable development are starkly evident. The Gulf relies on non-renewable oil and gas exports to supply the world's insatiable CO2 emitting energy demands, and has built unsustainable conurbations with water supplies dependent on energy hungry desalination plants and deep aquifers pumped beyond natural replenishment rates. Sustainable Development has an interdisciplinary focus, bringing together university faculty and government personnel from the Gulf, Europe, and North America -- including social and natural scientists, environmentalists and economists, architects and planners -- to discuss topics such as sustainable natural resource use and urbanization, industrial and technological development, economy and politics, history and geography.

Homotherium was a genus of large-bodied scimitar-toothed cats, morphologically distinct from any extant felid species, that went extinct at the end of the Pleistocene [1–4]. They possessed large, saber-form serrated canine teeth, powerful forelimbs, a sloping back, and an enlarged optic bulb, all of which were key characteristics for predation on Pleistocene megafauna [5]. Previous mitochondrial DNA phylogenies suggested that it was a highly divergent sister lineage to all extant cat species [6–8]. However, mitochondrial phylogenies can be misled by hybridization [9], incomplete lineage sorting (ILS), or sex-biased dispersal patterns [10], which might be especially relevant for Homotherium since widespread mito-nuclear discrepancies have been uncovered in modern cats [10]. To examine the evolutionary history of Homotherium, we generated a 7x nuclear genome and a 38x exome from H. latidens using shotgun and target-capture sequencing approaches. Phylogenetic analyses reveal Homotherium as highly divergent (22.5 Ma) from living cat species, with no detectable signs of gene flow. Comparative genomic analyses found signatures of positive selection in several genes, including those involved in vision, cognitive function, and energy consumption, putatively consistent with diurnal activity, well-developed social behavior, and cursorial hunting [5]. Finally, we uncover relatively high levels of genetic diversity, suggesting that Homotherium may have been more abundant than the limited fossil record suggests [3, 4, 11–14]. Our findings complement and extend previous inferences from both the fossil record and initial molecular studies, enhancing our understanding of the evolution and ecology of this remarkable lineage. ; This project received funding from the European Union's Seventh Framework Programme for Research, Technological Development, and Demonstration under grant agreement no. FP7-PEOPLE-2011-IEF-298820 and ERC Consolidator Award 681396—Extinction Genomics to M.T.P.G. Portions of this manuscript were prepared while W.E.J. held a National Research Council Research Associateship Award at the Walter Reed Army Institute of Research (WRAIR).