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Evolutionary Significant Units (evolutionary + significant_unit)
Selected AbstractsEcological factors drive differentiation in wolves from British ColumbiaJOURNAL OF BIOGEOGRAPHY, Issue 8 2009Violeta Muñoz-Fuentes Abstract Aim, Limited population structure is predicted for vagile, generalist species, such as the grey wolf (Canis lupus L.). Our aims were to study how genetic variability of grey wolves was distributed in an area comprising different habitats that lay within the potential dispersal range of an individual and to make inferences about the impact of ecology on population structure. Location, British Columbia, Canada , which is characterized by a continuum of biogeoclimatic zones across which grey wolves are distributed , and adjacent areas in both Canada and Alaska, United States. Methods, We obtained mitochondrial DNA control region sequences from grey wolves from across the province and integrated our genetic results with data on phenotype, behaviour and ecology (distance, habitat and prey composition). We also compared the genetic diversity and differentiation of British Columbia grey wolves with those of other North American wolf populations. Results, We found strong genetic differentiation between adjacent populations of grey wolves from coastal and inland British Columbia. We show that the most likely factor explaining this differentiation is habitat discontinuity between the coastal and interior regions of British Columbia, as opposed to geographic distance or physical barriers to dispersal. We hypothesize that dispersing grey wolves select habitats similar to the one in which they were reared, and that this differentiation is maintained largely through behavioural mechanisms. Main conclusions, The identification of strong genetic structure on a scale within the dispersing capabilities of an individual suggests that ecological factors are driving wolf differentiation in British Columbia. Coastal wolves are highly distinct and representative of a unique ecosystem, whereas inland British Columbia grey wolves are more similar to adjacent populations of wolves located in Alaska, Alberta and Northwest Territories. Given their unique ecological, morphological, behavioural and genetic characteristics, grey wolves of coastal British Columbia should be considered an Evolutionary Significant Unit (ESU) and, consequently, warrant special conservation status. If ecology can drive differentiation in a highly mobile generalist such as the grey wolf, ecology probably drives differentiation in many other species as well. [source] A population genetic comparison of argali sheep (Ovis ammon) in Mongolia using the ND5 gene of mitochondrial DNA; implications for conservationMOLECULAR ECOLOGY, Issue 5 2004T. Tserenbataa Abstract We sequenced 556 bp of the mitochondrial ND5 gene to infer aspects of population structure and to test subspecific designations of argali sheep (Ovis ammon) in Mongolia. Analysis of molecular variance (amova) revealed greater variation within than among putative subspecies and populations, suggesting high levels female-mediated gene flow. Compared with bighorn sheep (O. canadensis) in North America, substantially less differentiation in mitochondrial DNA was found among argali populations over 1200 km than was found among bighorn populations over 250 km. This result is consistent with differences in argali and bighorn life history traits. Argali run for long distances across open terrain in the presence of a threat rather than running up into steep escape terrain like bighorn sheep do. Our results suggest recognizing only one Evolutionary Significant Unit (subspecies) of argali in Mongolia, but they may support recognizing two Management Units, because two regions do exhibit slightly different haplotype frequencies at the ND5 gene of mtDNA. [source] Rarity and decline in palaeoendemic Martino's vole Dinaromys bogdanoviMAMMAL REVIEW, Issue 4 2008BORIS KRY, TUFEK ABSTRACT 1Martino's vole Dinaromys bogdanovi is the only living member of the Tertiary genus Dinaromys, and probably also the only surviving member of the Pliomys lineage. The range of the genus Dinaromys has historically been small and its rate of evolution has been low. 2Martino's vole shows all three attributes of rarity in accordance with Rabinowitz's ,seven forms of rarity' model: (i) its range is estimated at 43 545 km2 but the area of occupancy is <5200 km2; (ii) its habitat requirements are narrow and the species is strictly tied to exposed, karstified bedrock; and (iii) current populations are invariably small and frequently isolated. 3The Pleistocene range of Martino's vole exceeded the recent one, at least in the north-western part of the Balkans, and its shrinkage continued into the Holocene. 4Martino's vole may be in competition with the European snow vole Chionomys nivalis, which has a very similar morphology and presumably identical habitat requirements, but is shifted towards an r-selected life-history strategy. Long-term sympatry of these voles has probably resulted in competitive exclusion of the relatively K-selected Martino's vole by the relatively r-selected European snow vole. 5Martino's vole consists of two deeply divergent (about one million years ago) phylogeographical lineages, which may represent distinct cryptic species. Rarity is particularly pronounced in the north-western lineage to the west of the Neretva River, where rocky habitats are largely occupied by the European snow vole. 6In the IUCN Red List of Threatened Animals, Martino's vole is classified as ,near threatened'. However, the north-western lineage, which is phylogeographically most divergent and has the greatest genetic diversity, is classed as a ,vulnerable' evolutionary significant unit on the basis of its small area of occupancy (<2000 km2). Long-term population monitoring is an essential step in evaluating the conservation needs of Martino's vole. [source] Subpopulations of Cryptocephalus beetles (Coleoptera: Chrysomelidae): geographically close but genetically farDIVERSITY AND DISTRIBUTIONS, Issue 1 2003R. W. Piper Abstract. The leaf beetles Cryptocephalus coryli, C. decemmaculatus and C. nitidulus are of conservation concern and are included on the UK Biodiversity Action Plan. The distinctiveness of the disjunct remaining populations of these beetles was compared to that of more continuously distributed Cryptocephalus species. This was carried out with a view to defining evolutionary significant units (ESUs) in the rare species. A portion of the cytochrome b gene, an intergenic spacer and partial tRNA was analysed from 93 specimens of Cryptocephalus beetle (Coleoptera: Chrysomelidae). Considerable sequence divergence was apparent in all the species, even at an intersite scale when the distances between sampled localities were very small (< 1 km). Intrapopulation, intersite and interpopulation divergence observed in the rare species was reflected in the species that have a more continuous distribution, implying that dispersal ability in these species is poor and gene flow can be impeded by relatively trivial barriers to dispersal. The evidence suggests that the disjunct populations of the rare Cryptocephalus species can, tentatively, be considered as ESUs. This has important implications for management strategies and reintroductions. [source] Genetic diversity of captive binturongs (Arctictis binturong, Viverridae, Carnivora): implications for conservationJOURNAL OF ZOOLOGY, Issue 4 2007L. Cosson Abstract The binturong Arctictis binturong is a threatened carnivore (Mammalia) that ranges throughout the forests of South-east Asia. This study evaluates the genetic diversity of captive binturong populations in European zoos and attempts to assess their geographic origin. We sequenced the hypervariable region 1 of the mitochondrial control region of 56 binturongs, among which 20 had a known geographic origin. We showed that at least two distinct geographic clades exist and were able to assess the geographic clade to which captive individuals belong. Moreover, a low genetic diversity was observed among the captive population of European zoos. Although our results are preliminary, zoo managers should consider the evolutionary significant units identified by this study, and which correspond to recognized sub-species, when planning binturong reproduction programs. [source] Molecular systematics of cowries (Gastropoda: Cypraeidae) and diversification patterns in the tropicsBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2003CHRISTOPHER P. MEYER This study produces a nearly comprehensive phylogeny for the marine gastropod group Cypraeidae (cowries) and uses this topology to examine diversification patterns in the tropics. The dataset is based on molecular sequence data from two mitochondrial genes and includes 210 evolutionary significant units (ESUs) from 170 recognized species (>80%). Systematics for the group is revised based on well-supported clades, and tree topology is generally consistent with previously proposed classification schemes. Three new genera are introduced (Cryptocypraea gen. nov, Palmulacypraea gen. nov, and Contradusta gen. nov) and two previous genera are resurrected (Perisserosa and Eclogavena). One new tribe is proposed (Bistolidini). Topologies produced by a range of transition:transversion (Ti:Tv) weighting schemes in parsimony are pooled and evaluated using maximum likelihood criteria. Extensive geographical coverage shows persistent, large-scale geographical structure in sister-groups. Genetic divergence between subspecies is often equivalent or even greater than that between recognized species. Using ESUs as a metric, diversity throughout the Indo-West Pacific (IWP) increases by 38%. Intra- and inter-regional diversification patterns show that the IWP is the centre for speciation in cowries. The other major tropical regions of the world are inhabited by a predominantly relictual fauna; from a cowrie's eye-view. Good dispersal ability begets larger ranges, increased extinction resistance and morphological stasis; whereas shorter larval duration results in smaller ranges, higher speciation rates, but also higher turnover. Larval duration and dispersal ability appear correlated with ocean productivity as taxa with longer-lived larvae are associated with oligotrophic conditions; whereas taxa with shorter larval durations are associated with eutrophic, continental conditions. This tendency is carried to the extreme in temperate or upwelling regions where a planktonic phase is completely lost and crawl-away larvae evolve multiple times. A strong phylogenetic trend supports these observations as lineages leading up to and including the derived Indo-West Pacific Erroneinae clade contain taxa predominantly restricted to continental habitats and have undergone the greatest evolutionary radiations in their respective regions. © 2003 The Linnean Society of London, Biological Journal of the Linnean Society, 2003, 79, 401, 459. [source] | |||||||||||||||||||