Sökning: "fylogeni"

Visar resultat 16 - 20 av 39 avhandlingar innehållade ordet fylogeni.

  1. 16. Decoding the fossil record of early lophophorates : Systematics and phylogeny of problematic Cambrian Lophotrochozoa

    Författare :Aodhán D. Butler; Michael Streng; Lars E. Holmer; Russell Garwood; Maggie Cusack; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Brachiopoda; Chengjiang; Lagerstätte; Cambrian Explosion; palaeobiology; stem-group; entoproct; phoronid; tommotiid; exceptional preservation; Earth Science with specialization in Historical Geology and Palaeontology; Geovetenskap med inriktning mot historisk geologi och paleontologi;

    Sammanfattning : The evolutionary origins of animal phyla are intimately linked with the Cambrian explosion, a period of radical ecological and evolutionary innovation that begins approximately 540 Mya and continues for some 20 million years, during which most major animal groups appear. Lophotrochozoa, a major group of protostome animals that includes molluscs, annelids and brachiopods, represent a significant component of the oldest known fossil records of biomineralised animals, as disclosed by the enigmatic ‘small shelly fossil’ faunas of the early Cambrian. LÄS MER

  3. 17. Reticulate Evolution in Diphasiastrum (Lycopodiaceae)

    Författare :Sunniva Margrethe Due Aagaard; Niklas Wikström; Tom A. Ranker; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; admixture analysis; Bayesian clustering; Diphasiastrum; Feulgen DNA image densitometry; homoploid hybridization; Lycopodiaceae; phylogenetic analysis; polyploidy; reticulate evolution; Systematics and phylogenetics; Systematik och fylogeni; systematisk botanik; Systematic Botany;

    Sammanfattning : In this thesis relationships and the occurrence of reticulate evolutionary events in the club moss genus Diphasiastrum are investigated. Diphasiastrum is initially established as a monophyletic group within Lycopodiaceae using non recombinant chloroplast sequence data. LÄS MER

  4. 18. Species Limits, and Evolutionary History of Glassfrogs

    Författare :Santiago Castroviejo-Fisher; Carles Vilà; Jennifer A. Leonard; Miguel Vences; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Amphibia; Anura; Biogeography; Centrolenidae; Diversification; Frogs; Molecular Phylogenetics; Neotropics; Pristimantis; Speciation; Species; Systematics; Taxonomy; Systematics and phylogenetics; Systematik och fylogeni; systematisk zoologi; Systematic Zoology;

    Sammanfattning : Recognizing the mechanisms of speciation and the limits of species is essential to understand the origin of biodiversity and how to conserve it. The general aims of my investigations during my doctoral studies were two-fold: to study evolutionary patterns and processes, and to provide specific and superspecific taxonomic classifications that try to reflect evolutionary history. LÄS MER

  5. 19. Population Genetic Structure of Black Grouse (Tetrao tetrix) : From a Large to a Fine Scale Perspective

    Författare :Carolina Corrales Duque; Jacob Höglund; Staffan Bensch; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; black grouse; control region; demographic expansion; kin selection; lek; microsatellites; non-invasive sampling; postglacial colonisation; philopatry; phylogeography; sex-biased dispersal; spatial genetics; subspecies; suture zone; refugia; Biology; Biologi; Systematics and phylogenetics; Systematik och fylogeni; Biologi med inriktning mot populationsbiologi; Biology with specialization in Population Biology;

    Sammanfattning : Black grouse (Tetrao tetrix) is a bird species with a lek mating system found in the Palearctic boreal taiga. It is assumed that it has a continuous distribution along Scandinavia and Siberia, whereas in Central Europe it has declined during the last decades. LÄS MER

  7. 20. Phylogenetic and ecological studies in lichenology : including studies of both mycobiont and photobiont

    Författare :Åsa Dahlkild; Anders Tehler; Ingvar Kärnefelt; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Phylogeny; ecology; lichen; photobiont; mycobiont; Systematics and phylogenetics; Systematik och fylogeni;

    Sammanfattning : In this thesis different aspects in lichens are investigated, namely, the phylogeny of mycobiont and photobiont, and ecology in the form of species richness of certain habitats of the Uppland province, Sweden.Analyses of ITS sequences of the lichenized fungi genus Roccella (Roccellaceae) provide an intrageneric topology of the genus with emphasis on the European, Mediterranean and Macaronesian species. LÄS MER