TY - JOUR A1 - Kehlmaier, Christian A1 - Barlow, Axel A1 - Hastings, Alexander K. A1 - Vamberger, Melita A1 - Paijmans, Johanna L. A. A1 - Steadman, David W. A1 - Albury, Nancy A. A1 - Franz, Richard A1 - Hofreiter, Michael A1 - Fritz, Uwe T1 - Tropical ancient DNA reveals relationships of the extinct bahamian giant tortoise Chelonoidis alburyorum JF - Proceedings of the Royal Society of London : Series B, Biological sciences N2 - Ancient DNA of extinct species from the Pleistocene and Holocene has provided valuable evolutionary insights. However, these are largely restricted to mammals and high latitudes because DNA preservation in warm climates is typically poor. In the tropics and subtropics, non-avian reptiles constitute a significant part of the fauna and little is known about the genetics of the many extinct reptiles from tropical islands. We have reconstructed the near-complete mitochondrial genome of an extinct giant tortoise from the Bahamas (Chelonoidis alburyorum) using an approximately 1000-year-old humerus from a water-filled sinkhole (blue hole) on Great Abaco Island. Phylogenetic and molecular clock analyses place this extinct species as closely related to Galapagos (C. niger complex) and Chaco tortoises (C. chilensis), and provide evidence for repeated overseas dispersal in this tortoise group. The ancestors of extant Chelonoidis species arrived in South America from Africa only after the opening of the Atlantic Ocean and dispersed from there to the Caribbean and the Galapagos Islands. Our results also suggest that the anoxic, thermally buffered environment of blue holes may enhance DNA preservation, and thus are opening a window for better understanding evolution and population history of extinct tropical species, which would likely still exist without human impact. KW - Bahamas KW - biogeography KW - extinction KW - palaeontology KW - phylogeny Y1 - 2017 U6 - https://doi.org/10.1098/rspb.2016.2235 SN - 0962-8452 SN - 1471-2954 VL - 284 PB - The Royal Society CY - London ER - TY - JOUR A1 - Radchuk, Viktoriia A1 - De Laender, Frederik A1 - Cabral, Juliano Sarmento A1 - Boulangeat, Isabelle A1 - Crawford, Michael Scott A1 - Bohn, Friedrich A1 - De Raedt, Jonathan A1 - Scherer, Cedric A1 - Svenning, Jens-Christian A1 - Thonicke, Kirsten A1 - Schurr, Frank M. A1 - Grimm, Volker A1 - Kramer-Schadt, Stephanie T1 - The dimensionality of stability depends on disturbance type JF - Ecology letters N2 - Ecosystems respond in various ways to disturbances. Quantifying ecological stability therefore requires inspecting multiple stability properties, such as resistance, recovery, persistence and invariability. Correlations among these properties can reduce the dimensionality of stability, simplifying the study of environmental effects on ecosystems. A key question is how the kind of disturbance affects these correlations. We here investigated the effect of three disturbance types (random, species-specific, local) applied at four intensity levels, on the dimensionality of stability at the population and community level. We used previously parameterized models that represent five natural communities, varying in species richness and the number of trophic levels. We found that disturbance type but not intensity affected the dimensionality of stability and only at the population level. The dimensionality of stability also varied greatly among species and communities. Therefore, studying stability cannot be simplified to using a single metric and multi-dimensional assessments are still to be recommended. KW - Community model KW - disturbance intensity KW - disturbance type KW - extinction KW - individual-based model KW - invariability KW - persistence KW - recovery KW - resistance Y1 - 2019 U6 - https://doi.org/10.1111/ele.13226 SN - 1461-023X SN - 1461-0248 VL - 22 IS - 4 SP - 674 EP - 684 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Seifert, Linda I. A1 - Weithoff, Guntram A1 - Vos, Matthijs T1 - Extreme heat changes post-heat wave community reassembly JF - Ecology and evolution N2 - Climate forecasts project further increases in extremely high-temperature events. These present threats to biodiversity, as they promote population declines and local species extinctions. This implies that ecological communities will need to rely more strongly on recovery processes, such as recolonization from a meta-community context. It is poorly understood how differences in extreme event intensity change the outcome of subsequent community reassembly and if such extremes modify the biotic environment in ways that would prevent the successful re-establishment of lost species. We studied replicated aquatic communities consisting of algae and herbivorous rotifers in a design that involved a control and two different heat wave intensity treatments (29 degrees C and 39 degrees C). Animal species that suffered heat-induced extinction were subsequently re-introduced at the same time and density, in each of the two treatments. The 39 degrees C treatment led to community closure in all replicates, meaning that a previously successful herbivore species could not re-establish itself in the postheat wave community. In contrast, such closure never occurred after a 29 degrees C event. Heat wave intensity determined the number of herbivore extinctions and strongly affected algal relative abundances. Re-introduced herbivore species were thus confronted with significantly different food environments. This ecological legacy generated by heat wave intensity led to differences in the failure or success of herbivore species re-introductions. Reassembly was significantly more variable, and hence less predictable, after an extreme heat wave, and was more canalized after a moderate one. Our results pertain to relatively simple communities, but they suggest that ecological legacies introduced by extremely high-temperature events may change subsequent ecological recovery and even prevent the successful re-establishment of lost species. Knowing the processes promoting and preventing ecological recovery is crucial to the success of species re-introduction programs and to our ability to restore ecosystems damaged by environmental extremes. KW - Biodiversity KW - climate change KW - conservation KW - ecological restoration KW - extinction KW - extreme temperature events KW - global warming KW - maximum temperature KW - variability Y1 - 2015 U6 - https://doi.org/10.1002/ece3.1490 SN - 2045-7758 VL - 5 IS - 11 SP - 2140 EP - 2148 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - González-Fortes, Gloria M. A1 - Kolbe, Ben A1 - Fernandes, Daniel A1 - Meleg, Ioana N. A1 - Garcia-Vazquez, Ana A1 - Pinto-Llona, Ana C. A1 - Constantin, Silviu A1 - de Torres, Trino J. A1 - Ortiz, Jose E. A1 - Frischauf, Christine A1 - Rabeder, Gernot A1 - Hofreiter, Michael A1 - Barlow, Axel T1 - Ancient DNA reveals differences in behaviour and sociality between brown bears and extinct cave bears JF - Molecular ecology N2 - Ancient DNA studies have revolutionized the study of extinct species and populations, providing insights on phylogeny, phylogeography, admixture and demographic history. However, inferences on behaviour and sociality have been far less frequent. Here, we investigate the complete mitochondrial genomes of extinct Late Pleistocene cave bears and middle Holocene brown bears that each inhabited multiple geographically proximate caves in northern Spain. In cave bears, we find that, although most caves were occupied simultaneously, each cave almost exclusively contains a unique lineage of closely related haplotypes. This remarkable pattern suggests extreme fidelity to their birth site in cave bears, best described as homing behaviour, and that cave bears formed stable maternal social groups at least for hibernation. In contrast, brown bears do not show any strong association of mitochondrial lineage and cave, suggesting that these two closely related species differed in aspects of their behaviour and sociality. This difference is likely to have contributed to cave bear extinction, which occurred at a time in which competition for caves between bears and humans was likely intense and the ability to rapidly colonize new hibernation sites would have been crucial for the survival of a species so dependent on caves for hibernation as cave bears. Our study demonstrates the potential of ancient DNA to uncover patterns of behaviour and sociality in ancient species and populations, even those that went extinct many tens of thousands of years ago. KW - ancient DNA KW - extinction KW - homing KW - sociality KW - Ursus arctos KW - Ursus spelaeus Y1 - 2016 U6 - https://doi.org/10.1111/mec.13800 SN - 0962-1083 SN - 1365-294X VL - 25 SP - 4907 EP - 4918 PB - Wiley-Blackwell CY - Hoboken ER -