Sökning: "taxon"

Visar resultat 1 - 5 av 58 avhandlingar innehållade ordet taxon.

  1. 1. A multi-faceted approach to a "dark taxon" : The hyperdiverse and poorly known scuttle flies (Diptera: Phoridae)

    Författare :Emily Hartop; Fredrik Ronquist; Torbjørn Ekrem; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; biodiversity; taxonomy; dark taxa; Systematic Zoology; zoologisk systematik och evolutionsforskning;

    Sammanfattning : Most of the unknown animal biodiversity on earth is in groups of invertebrates that are hyperdiverse and abundant, yet poorly known (“dark taxa”). The study of these organisms requires a multi-faceted approach and methodologies designed to tackle large numbers of species and specimens. LÄS MER

  2. 2. Systematics of Grania (Clitellata: Enchytraeidae), an interstitial annelid taxon

    Författare :Pierre De Wit; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :Clitellata; Oligochaeta; Enchytraeidae; Grania; interstitial habitat; systematics; phylogeny; DNA barcoding; cryptic species;

    Sammanfattning : In between the grains of sand on the ocean floor, there exists a world which few people are aware of. Representatives of almost all animal phyla can be found here. LÄS MER

  3. 3. The Dawn of a New Age : Interrelationships of Acoela and Nemertodermatida and the Early Evolution of Bilateria

    Författare :Andreas Wallberg; Ulf Jondelius; Mikael Thollesson; Graham Budd; Gonzalo Giribet; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Acoela; Nemertodermatida; Bilateria; Metazoa; evolution; phylogenetic inferrence; ancestral reconstruction; taxon sampling; microRNA; Systematics and phylogenetics; Systematik och fylogeni; systematisk zoologi; Systematic Zoology;

    Sammanfattning : Deciphering the rapid emergence of bilaterian animals around the time of the Cambrian Explosion and reconstructing the interrelationships of animal groups have long been two of the most elusive problems in Zoology. This thesis concerns the phylogenetic interrelationships within and among Acoela and Nemertodermatida, two groups of small worms that are believed to be basal bilaterians and which may provide important clues for understanding the early evolution of animals. LÄS MER

  4. 4. Taxonomy, phylogeny, and secondary sexual character evolution of diving beetles, focusing on the genus Acilius

    Författare :Johannes Bergsten; Anders N. Nilsson; Jyrki Muona; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Biology; antagonistic coevolution; arms race; sexual conflict; diving beetle; Dytiscidae; Coleoptera; taxon sampling; long-branch attraction; parsimony; Bayesian analysis; taxonomic revision; Biologi; Biology; Biologi;

    Sammanfattning : Sexual conflict can lead to antagonistic coevolution between the sexes, but empirical examples are few. In this thesis secondary sexual characters in diving beetles are interpreted in the light of sexual conflict theory. LÄS MER

  5. 5. Integrative taxonomy of birds : Studies into the nature, origin and delimitation of species

    Författare :George Sangster; Per G. P. Ericson; Martin Päckert; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Aves; biogeography; integrative taxonomy; pluralism; ring species; speciation; species criteria; species limits; taxon chain; Systematic Zoology; zoologisk systematik och evolutionsforskning;

    Sammanfattning : Species are the basic currency in biodiversity studies but what constitutes a species has long been controversial. A major breakthough was the insight that most systematists agree that species are segments of population lineages, and that multiple lines of evidence should be employed and integrated, a procedure called integrative taxonomy. LÄS MER