58 research outputs found

    Climatic and vegetational drivers of insect beta diversity at the continental scale

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    Aim: We construct a framework for mapping pattern and drivers of insect diversity at the continental scale and use it to test whether and which environmental gradients drive insect beta diversity. Location: Global; North and Central America; Western Europe. Time period: 21st century. Major taxa studied: Insects. Methods: An informatics system was developed to integrate terrestrial data on insects with environmental parameters. We mined repositories of data for distribution, climatic data were retrieved (WorldClim), and vegetation parameters inferred from remote sensing analysis (MODIS Vegetation Continuous Fields). Beta diversity between sites was calculated and then modeled with two methods, Mantel test with multiple regression and generalized dissimilarity modeling. Results: Geographic distance was the main driver of insect beta diversity. Independent of geographic distance, bioclimate variables explained more variance in dissimilarity than vegetation variables, although the particular variables found to be significant were more consistent in the latter, particularly, tree cover. Tree cover gradients drove compositional dissimilarity at denser coverages, in both continental case studies. For climate, gradients in temperature parameters were significant in driving beta diversity more so than gradients in precipitation parameters. Main conclusions: Although environmental gradients drive insect beta diversity independently of geography, the relative contribution of different climatic and vegetational parameters is not expected to be consistent in different study systems. With further incorporation of additional temporal information and variables, this approach will enable the development of a predictive framework for conserving insect biodiversity at the global scale

    Species Diversity and Phylogeographical Affinities of the Branchiopoda (Crustacea) of Churchill, Manitoba, Canada

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    The region of Churchill, Manitoba, contains a wide variety of habitats representative of both the boreal forest and arctic tundra and has been used as a model site for biodiversity studies for nearly seven decades within Canada. Much previous work has been done in Churchill to study the Daphnia pulex species complex in particular, but no study has completed a wide-scale survey on the crustacean species that inhabit Churchill's aquatic ecosystems using molecular markers. We have employed DNA barcoding to study the diversity of the Branchiopoda (Crustacea) in a wide variety of freshwater habitats and to determine the likely origins of the Churchill fauna following the last glaciation. The standard animal barcode marker (COI) was sequenced for 327 specimens, and a 3% divergence threshold was used to delineate potential species. We found 42 provisional and valid branchiopod species from this survey alone, including several cryptic lineages, in comparison with the 25 previously recorded from previous ecological works. Using published sequence data, we explored the phylogeographic affinities of Churchill's branchiopods, finding that the Churchill fauna apparently originated from all directions from multiple glacial refugia (including southern, Beringian, and high arctic regions). Overall, these microcrustaceans are very diverse in Churchill and contain multiple species complexes. The present study introduces among the first sequences for some understudied genera, for which further work is required to delineate species boundaries and develop a more complete understanding of branchiopod diversity over a larger spatial scale

    Trends in DNA barcoding and metabarcoding

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    This open-access special issue features 12 full articles representing emerging trends from the international DNAbarcoding community. Several articles highlight how DNA-based techniques are elucidating the species diversity,biogeography, and conservation status of Africas biodiversity. Another prominent theme is the movementtowards big biodiversity data using high-throughput, individual-based DNA barcoding methods, which preservevoucher specimens and abundance data, as well as bulk sample-based metabarcoding. Methodological developments are enhancing the detection of specific species and whole communities using environmental DNA(eDNA) barcoding and metabarcoding. Data are also expanding in terms of genetic coverage; in this issue, a newdatabase is established for a secondary fungalDNAbarcode marker, and multi-kingdom, multi-marker biodiversitysurveys are gaining traction. DNA barcode sequence data, often combined with complementary markers or taxonomic information, are increasingly contributing to large-scale phylogenetic projects, with implications for understanding evolutionary history, community structure, and conservation priorities.Fil: Adamowicz, Sarah J.. University of Guelph; CanadáFil: Boatwright, James S.. University of The Western Cape; SudáfricaFil: Chain, Frédéric. University of Massachusetts; Estados UnidosFil: Fisher, Brian L.. California Academy Of Sciences.; Estados UnidosFil: Hogg, Ian D.. Polar Knowledge Canada; CanadáFil: Leese, Florian. Universitat Essen; AlemaniaFil: Lijtmaer, Dario Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Mwale, Monica. South African National Biodiversity Institute; SudáfricaFil: Naaum, Amanda M.. The Queens University of Belfast; IrlandaFil: Pochon, Xavier. University of Auckland; Nueva ZelandaFil: Schubert, Dirk W.. University of Guelph; CanadáFil: Wilson, John James. National Museums Liverpool; Reino UnidoFil: Wood, Susanna. Cawthron Institute; Nueva ZelandaFil: Xu, Jianping. Mcmaster University; CanadáFil: Xu, Sen. University of Texas at Arlington; Estados UnidosFil: Zhou, Xin. China Agricultural University; ChinaFil: Van Der Bank, Michelle. University of Johannesburg; Sudáfric

    The Hyalella (Crustacea: Amphipoda) species cloud of the ancient Lake Titicaca originated from multiple colonizations

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    The final publication is available at Elsevier via https://doi.org/10.1016/j.ympev.2018.03.004. © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Ancient lakes are renowned for their exceptional diversity of endemic species. As model systems for the study of sympatric speciation, it is necessary to understand whether a given hypothesized species flock is of monophyletic or polyphyletic origin. Here, we present the first molecular characterization of the Hyalella (Crustacea: Amphipoda) species complex of Lake Titicaca, using COI and 28S DNA sequences, including samples from the connected Small and Large Lakes that comprise Lake Titicaca as well as from a broader survey of southern South American sites. At least five evolutionarily distant lineages are present within Lake Titicaca, which were estimated to have diverged from one another 12–20 MYA. These major lineages are dispersed throughout the broader South American Hyalella phylogeny, with each lineage representing at least one independent colonization of the lake. Moreover, complex genetic relationships are revealed between Lake Titicaca individuals and those from surrounding water bodies, which may be explained by repeated dispersal into and out of the lake, combined with parallel intralacustrine diversification within two separate clades. Although further work in deeper waters will be required to determine the number of species present and modes of diversification, our results strongly indicate that this amphipod species cloud is polyphyletic with a complex geographic history.Natural Sciences and Engineering Research Council || Discovery Grant 2012-327509Natural Sciences and Engineering Research Council || Discovery Grant 386591-2010Natural Sciences and Engineering Research Council || Undergraduate Student Research AwardsNatural Sciences and Engineering Research Council || Postdoctoral FellowshipCatholic University of Temuco, Research Direction || Limnology Project DGI-DCA 2007-01, Project MECESUP UCT 080

    1. Whole-tree dN/dS and overall substitution rates analysis

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    This folder contains the input and output files used in and obtained from the program PAML (Yang 2007) for the whole-tree analysis of dN/dS ratios (program component codeml) and overall substitution rates (program component baseml). This folder is organised into subfolders by source study name and then by gene. The numbers at the beginning of the folder names do not have significance and are only used for organisational purposes. Note both analyses types (codeml and baseml) use the same tree and nucleotide files. Each gene folder contains 6 files: 2 control files (1 codeml, 1 baseml - “.ctl”), 1 nucleotide file (“.nuc”), 1 tree file (“.trees”), 2 output files (1 codeml, 1 baseml)

    2. dN/dS ratio sister-clades analysis

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    This folder contains the input and output files used in and obtained from the program PAML (Yang 2007) for the sister-clade analysis of dN/dS ratios (program component codeml). This folder is organised into subfolders by source study name and then by gene. The numbers at the beginning of the folder names do not have significance and are only used for organisational purposes. Each gene folder contains 4 files: 1 control file (“.ctl”), 1 nucleotide file (“.nuc”), 1 tree file (“.trees”), and 1 output file
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