12 research outputs found

    Bibliography of the Siberian newt (Salamandrella keyserlingii Dybowski, 1870)

    No full text
    Volume: 102Start Page: 1End Page: 5

    Validity and Systematic Position of Rana altaica (Rana: Ranidae): Results of a Phylogenetic Analysis

    No full text
    In order to evaluate the phylogenetic position and validity of Rana altaica , we investigated the phylogeny of brown frogs in Eurasia by Bayesian Inference and Maximum Parsimony analyses of a fragment from the mitochondrial DNA gene Cytochrome b. Both analyses resolved R. altaica as nesting deeply within R. arvalis. Most samples of the nominal R. altaica from the Altai region and specimens from Central Siberia shared a haplotype with R. arvalis. The matrilineal relationships suggested that R. altaica should be considered as a junior synonym of R. arvalis. Furthermore, our study suggested that the species group division of Chinese brown frogs should be re-evaluated within a phylogenetic context

    Data from: Spatiotemporal diversification of the true frogs (Genus Rana): a historical framework for a widely studied group of model organisms

    No full text
    True frogs of the genus Rana are widely used as model organisms in studies of development, genetics, physiology, ecology, behavior, and evolution. Comparative studies among the more than 100 species of Rana rely on an understanding of the evolutionary history and patterns of diversification of the group. We estimate a well-resolved, time-calibrated phylogeny from sequences of six nuclear and three mitochondrial loci sampled from most species of Rana, and use that phylogeny to clarify the group’s diversification and global biogeography. Our analyses consistently support an “Out of Asia” pattern with two independent dispersals of Rana from East Asia to North America via Beringian land bridges. The more species-rich lineage of New World Rana appears to have experienced a rapid radiation following its colonization of the New World, especially with its expansion into montane and tropical areas of Mexico, Central America, and South America. In contrast, Old World Rana exhibit different trajectories of diversification; diversification in the Old World began very slowly and later underwent a distinct increase in speciation rate around 29–18 Ma. Net diversification is associated with environmental changes and especially intensive tectonic movements along the Asian margin from the Oligocene to early Miocene. Our phylogeny further suggests that previous classifications were misled by morphological homoplasy and plesiomorphic color patterns, as well as a reliance primarily on mitochondrial genes. We provide a phylogenetic taxonomy based on analyses of multiple nuclear and mitochondrial gene loci

    Quantitative evidence for global amphibian population declines

    Full text link
    Although there is growing concern that amphibian populations are declining globally1±3, much of the supporting evidence is either anecdotal4,5 or derived from short-term studies at small geographical scales6±8. This raises questions not only about the dificulty of detecting temporal trends in populations which are notoriously variable9,10, but also about the validity of inferring global trends from local or regional studies11,12. Here we use data from 936 populations to assess large-scale temporal and spatial variations in amphibian population trends. On a global scale, our results indicate relatively rapid declines from the late 1950s/early 1960s to the late 1960s, followed by a reduced rate of decline to the present. Amphibian population trends during the 1960s were negative in western Europe (including the United Kingdom) and North America, but only the latter populations showed declines from the 1970s to the late 1990s. These results suggest that while large-scale trends show considerable geographical and temporal variability, amphibian populations are in fact declining-and that this decline has been happening for several decades
    corecore