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Comprehensive Taxonomic Sampling (comprehensive + taxonomic_sampling)
Selected AbstractsMolecular clocks keep dispersal hypotheses afloat: evidence for trans-Atlantic rafting by rodentsJOURNAL OF BIOGEOGRAPHY, Issue 2 2010Diane L. Rowe Abstract Aim, In order to resolve disputed biogeographical histories of biota with Gondwanan continental distributions, and to assess the null hypothesis of vicariance, it is imperative that a robust geological time-frame be established. As an example, the sudden and coincident appearance of hystricognath rodents (Rodentia: Hystricognathi) on both the African and South American continents has been an irreconcilable controversy for evolutionary biologists, presenting enigmas for both Gondwanan vicariance and Late Eocene dispersal hypotheses. In an attempt to resolve this discordance, we aim to provide a more robust phylogenetic hypothesis and improve divergence-date estimates, which are essential to assessing the null hypothesis of vicariance biogeography. Location, The primary centres of distribution are in Africa and South America. Methods, We implemented parsimony, maximum-likelihood and Bayesian methods to generate a phylogeny of 37 hystricognath taxa, the most comprehensive taxonomic sampling of this group to date, on the basis of two nuclear gene regions. To increase phylogenetic resolution at the basal nodes, these data were combined with previously published data for six additional nuclear gene regions. Divergence dates were estimated using two relaxed-molecular-clock methods, Bayesian multidivtime and nonparametric rate smoothing. Results, Our data do not support reciprocal monophyly of African and South American lineages. Indeed, Old World porcupines (i.e. Hystricomorpha) appear to be more closely related to New World lineages (i.e. Caviomorpha) than to other Old World families (i.e. Bathyergidae, Petromuridae and Thryonomyidae). The divergence between the monophyletic assemblage of South American lineages and its Old World ancestor was estimated to have occurred c. 50 Ma. Main conclusions, Our phylogenetic hypothesis and divergence-date estimates are strongly at odds with Gondwanan-vicariance isolating mechanisms. In contrast, our data suggest that transoceanic dispersal has played a significant role in governing the contemporary distribution of hystricognath rodents. Molecular-clock analyses imply a trans-Tethys dispersal event, broadly confined to the Late Cretaceous, and trans-Atlantic dispersal within the Early Eocene. Our analyses also imply that the use of the oldest known South American rodent fossil as a calibration point has biased molecular-clock inferences. [source] Integrating numt pseudogenes into mitochondrial phylogenies: comment on ,Mitochondrial phylogeny of Arvicolinae using comprehensive taxonomic sampling yields new insights'BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009DEBORAH A. TRIANT No abstract is available for this article. [source] Reply to Triant D and DeWoody J: Integrating numt pseudogenes into mitochondrial phylogenies: comment on Mitochondrial phylogeny of Arvicolinae using comprehensive taxonomic sampling yields new insightsBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009ELENA V. BUZAN No abstract is available for this article. [source] Reconstructing the origins of praying mantises (Dictyoptera, Mantodea): the roles of Gondwanan vicariance and morphological convergenceCLADISTICS, Issue 5 2009Gavin J. Svenson A comprehensive taxonomic sampling of Mantodea (praying mantises), covering virtually all higher-level groups, was assembled to reconstruct the phylogeny of the order. Sequence data were generated from five mitochondrial and four nuclear loci (12S rRNA, 16S rRNA, 18S rRNA, 28S rRNA, Histone III, Cytochrome Oxidase I & II, NADH dehydrogenase subunit 4, and Wingless) for 329 mantis exemplars along with seven cockroach and eight termite species. Only seven of 14 families, 14 of 33 subfamilies, and seven of 14 tribes were recovered as monophyletic, indicating that phylogeny is largely incongruent with classification. Mapping biogeographical regions on the phylogeny demonstrated that our results adhere closer to biogeographical distributions than to classification. Specific patterns in distribution suggest that major morphological convergences have confounded taxonomists' ability to reconstruct natural groups. A major revision of higher-level relationships is in order through a comprehensive investigation of morphology and molecular data. We found that major mantis lineages diverged prior to and during the isolation of geographical regions and subsequent ecomorphic specializations within these regions may have led to convergences in morphology. Divergence time estimation places the origin of Mantodea at the beginning of the Jurassic with most modern mantises originating on Gondwana in the Cretaceous. The first major divergence among modern mantises occurred as a result of the north,south splitting of South America and Africa. Subsequent divergences resulted from the breakup of Gondwana. The position of the Indian subcontinent appears to be central to the diversification of Afrotropical and Indomalayan mantises while Antarctica may have served as the conduit for the mantis invasions into South America and Australasia. When India separated from Antarctica and drifted north it distributed mantis lineages back into the Afrotropics and carried a diverse taxonomic assemblage to Asia. [source] | ||||||||||