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Electrodes for blood pO2 and pCO2 determination 总被引:29,自引:0,他引:29
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Interpretation of the genetic composition and taxonomic history of wolves in the western Great Lakes region (WGLR) of the United States has long been debated and has become more important to their conservation given the recent changes in their status under the Endangered Species Act. Currently, the two competing hypotheses on WGLR wolves are that they resulted from hybridization between (i) grey wolves (Canis lupus) and western coyotes (C. latrans) or (ii) between grey wolves and eastern wolves (C. lycaon). We performed a genetic analysis of sympatric wolves and coyotes from the region to assess the degree of reproductive isolation between them and to clarify the taxonomic status of WGLR wolves. Based on data from maternal, paternal and bi‐parental genetic markers, we demonstrate a clear genetic distinction between sympatric wolves and coyotes and conclude that they are reproductively isolated and that wolf–coyote hybridization in the WGLR is uncommon. The data reject the hypothesis that wolves in the WGLR derive from hybridization between grey wolves and western coyotes, and we conclude that the extant WGLR wolf population is derived from hybridization between grey wolves and eastern wolves. Grey‐eastern wolf hybrids (C. lupus × lycaon) comprise a substantial population that extends across Michigan, Wisconsin, Minnesota and western Ontario. These findings have important implications for the conservation and management of wolves in North America, specifically concerning the overestimation of grey wolf numbers in the United States and the need to address policies for hybrids. 相似文献
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Vegetation dynamics of predator-free land-bridge islands 总被引:5,自引:1,他引:4
JOHN TERBORGH KENNETH FEELEY MILES SILMAN† PERCY NUÑEZ‡ BRADLEY BALUKJIAN 《Journal of Ecology》2006,94(2):253-263
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PHILLIP Q. SPINKS ROBERT C. THOMSON BILL HUGHES BRAD MOXLEY RAFE BROWN ARVIN DIESMOS H. BRADLEY SHAFFER 《Zoological Journal of the Linnean Society》2012,164(4):811-824
Loss of habitat and human exploitation have driven many turtle species to the brink of extinction, particularly in many parts of southern Asia. The spiny turtle (Heosemys spinosa) is a terrestrial species distributed throughout the Sundaland region of South‐East Asia. Despite international legislative protection, H. spinosa continues to be illegally collected for the food and traditional medicine markets of China. Given its widespread distribution, taxonomists have reasonably questioned whether H. spinosa truly represents a single evolutionary lineage or multiple undiagnosed species. Recently, a large and illegal shipment of rare, wild‐caught H. spinosa was confiscated in Hong Kong, China, and the turtles were eventually distributed to several zoos and academic collections. Based on analyses of these individuals, along with additional individuals from the pet trade and museum collections, we found concordant genetic and phenotypic variation, indicating that two distinct types of H. spinosa exist in this collection of turtles. Further characterization of this variation will require field surveys and the collection of additional morphological and genetic data from specimens of known geographic provenance. However, our data indicate that this highly exploited, endangered species may contain additional cryptic taxa, and emphasize the critical need for systematic evaluation of species before unrecognized variation is lost forever. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 811–824. 相似文献