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Hipsley C.A.,Leibniz Institute For Evolutions Und Biodiversitatsforschung | Miles D.B.,Ohio University | Muller J.,Leibniz Institute For Evolutions Und Biodiversitatsforschung | Muller J.,Berlin Brandenburg Institute of Advanced Biodiversity Research
Biology Letters | Year: 2014

While global variation in taxonomic diversity is strongly linked to latitude, the extent to which morphological disparity follows geographical gradients is less well known. We estimated patterns of lineage diversification, morphological disparity and rates of phenotypic evolution in the Old World lizard family Lacertidae, which displays a nearly inverse latitudinal diversity gradient with decreasing species richness towards the tropics. We found that lacertids exhibit relatively constant rates of lineage accumulation over time, although the majority of morphological variation appears to have originated during recent divergence events, resulting in increased partitioning of disparity within subclades. Among subclades, tropical arboreal taxa exhibited the fastest rates of shape change while temperate European taxa were the slowest, resulting in an inverse relationship between latitudinal diversity and rates of phenotypic evolution. This pattern demonstrates a compelling counterexample to the ecological opportunity theory of diversification, suggesting an uncoupling of the processes generating species diversity and morphological differentiation across spatial scales. © 2014 The Author(s) Published by the Royal Society. All rights reserved. Source


Muller M.E.H.,Leibniz Center for Agricultural Landscape Research | Muller M.E.H.,Berlin Brandenburg Institute of Advanced Biodiversity Research | Urban K.,Osnabruck University of Applied Sciences | Koppen R.,BAM Federal Institute of Materials Research and Testing | And 3 more authors.
World Mycotoxin Journal | Year: 2015

The role of mycotoxins in the microbial competition in an ecosystem or on the same host plant is still unclear. Therefore, a laboratory study was conducted to evaluate the influence of mycotoxins on growth and mycotoxin production of Fusarium and Alternaria fungi. Fusarium culmorum Fc13, Fusarium graminearum Fg23 and two Alternaria tenuissima isolates (At18 and At220) were incubated on wheat kernels supplemented with alternariol (AOH), tetramic acid derivates (TeA), deoxynivalenol (DON) and zearalenone (ZEA) in an in vitro test system. Fungal biomass was quantified by determining ergosterol content. Three Fusarium toxins (DON, nivalenol and ZEA) and three Alternaria toxins (AOH, alternariol methyl ether (AME) and altenuene) were analysed by HPLC-MS/MS. If Alternaria strains grew in wheat kernels spiked with Fusarium mycotoxins, their growth rates were moderately increased, their AOH and AME production was enhanced and they were simultaneously capable of degrading the Fusarium mycotoxins DON and ZEA. In contrast, both Fusarium strains behaved quite differently. The growth rate of Fc13 was not distinctly influenced, while Fg23 increased its growth in wheat kernels spiked with AOH. TeA depressed the ergosterol content in Fc13 as well as in Fg23. The DON production of Fc13 was slightly depressed, whereas the ZEA production was significantly increased. In contrast, Fg23 restricted its ZEA production. Both Fusarium strains were not capable of degrading the Alternaria mycotoxin AOH. Mycotoxins might play an important role in the interfungal competitive processes. They influence growth rates and mycotoxin production of the antagonistic combatants. The observed effects between phytopathogenic Alternaria and Fusarium strains and their mycotoxins aid the understanding of the complexity of microbial competitive behaviour in natural environments. © 2014 Wageningen Academic Publishers. Source


Mikolajewski D.J.,Free University of Berlin | Rusen L.,Free University of Berlin | Mauersberger R.,Forderverein Feldberg Uckermarkische Seenlandschaft e.V. | Johansson F.,Uppsala University | And 2 more authors.
Journal of Evolutionary Biology | Year: 2015

Although changes in magnitude of single traits responding to selective agents have been studied intensively, little is known about selection shaping networks of traits and their patterns of covariation. However, this is central for our understanding of phenotypic evolution as traits are embedded in a multivariate environment with selection affecting a multitude of traits simultaneously rather than individually. Here, we investigate inter- and intraspecific patterns of trait integration (trait correlations) in the larval abdomen of dragonflies as a response to a change in predator selection. Species of the dragonfly genus Leucorrhinia underwent a larval habitat shift from predatory fish to predatory dragonfly-dominated lakes with an associated relaxation in selection pressure from fish predation. Our results indicate that the habitat-shift-induced relaxed selection pressure caused phenotypic integration of abdominal traits to be reduced. Intraspecific findings matched patterns comparing species from both habitats with higher abdominal integration in response to predatory fish. This higher integration is probably a result of faster burst swimming speed. The abdomen holds the necessary morphological machinery to successfully evade predatory fish via burst swimming. Hence, abdominal traits have to function in a tight coordinated manner, as maladaptive variation and consequently nonoptimal burst swimming would cause increased mortality. In predatory dragonfly-dominated lakes, no such strong link between burst swimming and mortality is present. Our findings highlight the importance of studying multivariate trait relationships as a response to selection for understanding patterns of phenotypic diversification. © 2015 European Society For Evolutionary Biology. Source


Pfestorf H.,University of Potsdam | Korner K.,University of Potsdam | Sonnemann I.,Free University of Berlin | Wurst S.,Free University of Berlin | And 3 more authors.
Journal of Vegetation Science | Year: 2016

Question: The empirical evidence of root herbivory effects on plant community composition and co-existence is contradictory. This originates from difficulties connected to below-ground research and confinement of experimental studies to a small range of environmental conditions. Here we suggest coupling experimental data with an individual-based model to overcome the limitations inherent in either approach. To demonstrate this, we investigated the consequences of root herbivory, as experimentally observed on individual plants, on plant competition and co-existence in a population and community context under different root herbivory intensities (RHI), fluctuating and constant root herbivore activity and grazing along a resource gradient. Location: Berlin, Germany, glasshouse; Potsdam, Germany, high performance cluster computer. Methods: The well-established community model IBC-Grass was adapted to allow for a flexible species parameterization and to include annual species. Experimentally observed root herbivory effects on performance of eight common grassland plant species were incorporated into the model by altering plant growth rates. We then determined root herbivore effects on plant populations, competitive hierarchy and consequences for co-existence and community diversity. Results: Root herbivory reduced individual biomass, but temporal fluctuation allowed for compensation of herbivore effects. Reducing resource availability strongly shifted competitive hierarchies, with, however, more similar hierarchies along the gradient under root herbivory, pointing to reduced ecological species differences. Consequently, negative effects on co-existence and diversity prevailed, with the exception of a few positive effects on co-existence of selected species pairs. Temporal fluctuation alleviated but did not remove negative root herbivore effects, despite of the stronger influence of intra- compared to interspecific competition. Grazing in general augmented co-existence. Most interestingly, grazing interacted with RHI and resource availability by promoting positive effects of root herbivory. Conclusions: Through integrating experimental data on the scale of individual plants with a simulation model we verified that root herbivory could affect plant competition with consequences for species co-existence. Our approach demonstrates the benefit that accrues when empirical and modelling approaches are brought more closely together, and that gathering data on distinct processes and under specific conditions, combined with appropriate models, can be used to answer challenging research questions in a more general way. © 2016 International Association for Vegetation Science. Source


Hampe O.,Leibniz Institute For Evolutions Und Biodiversitatsforschung | Franke H.,Leibniz Institute For Evolutions Und Biodiversitatsforschung | Hipsley C.A.,Leibniz Institute For Evolutions Und Biodiversitatsforschung | Kardjilov N.,Helmholtz Center Berlin | And 2 more authors.
Journal of Morphology | Year: 2015

Being descendants of small terrestrial ungulate mammals, whales underwent enormous transformations during their evolutionary history, that is, extensive changes in anatomy, physiology, and behavior were evolved during secondary adaptations to life in water. However, still only little is known about whale ontogenetic development, which help to identify the timing and sequence of critical evolutionary events, such as modification of the cetacean ear. This is particularly true for baleen whales (Mysticeti), the group including the humpback whale Megaptera novaeangliae. We use high-resolution X-ray computed tomography to reinvestigate humpback whale fetuses from the Kükenthal collection at the Museum für Naturkunde, Berlin, thus, extending historic descriptions of their skeletogenesis and providing for the first time sequences of cranial ossification for this species. Principally, the ossification sequence of prenatal Megaptera follows a typical mammalian pattern with the anterior dermal bones being the first ossifying elements in the skull, starting with the dentary. In contrast to other mammals, the ectotympanic bone ossifies at an early stage. Alveolar structure can be observed in both the maxillae and dentaries in these early prenatal specimens but evidence for teeth is lacking. Although the possibility of obtaining new embryological material is unlikely due to conservation issues, our study shows that reexamination of existing specimens employing new technologies still holds promise for filling gaps in our knowledge of whale evolution and ontogeny. J. Morphol. 276:564-582, 2015. © 2015 Wiley Periodicals, Inc. Source

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