Sökning: "Morphometrics"

Visar resultat 6 - 9 av 9 avhandlingar innehållade ordet Morphometrics.

  1. 6. 100 million years of shark macroevolution : A morphometric dive into tooth shape diversity

    Författare :Mohamad Bazzi; Per Ahlberg; Matt Friedman; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sharks; Macroevolution; Extinction recovery dynamics; Geometric Morphometrics; Morphospace-Disparity Framework; Teeth; Biology with specialization in Evolutionary Organismal Biology; Biologi med inriktning mot evolutionär organismbiologi;

    Sammanfattning : Few vertebrate clades exhibit the evolutionary longevity and versatility of sharks, which constitute nearly half of all current chondrichthyan biodiversity and represent an ecological diversity of mid-to-apex trophic-level predators in both marine and freshwater environments. The rich fossil record of shark teeth from Mesozoic and Cenozoic rocks also makes the group amenable to large-scale quantitative analyses. LÄS MER

  3. 7. 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 :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

  4. 8. The Interplay Between Selection And Constraints On Adaptive Divergence And Phenotypic Evolution

    Författare :Fabrice Eroukhmanoff; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Selection; Constraints; Adaptive Divergence; G-matrix; Gene Flow.; Speciation;

    Sammanfattning : Under natural or sexual selection, individuals with advantageous traits or combinations of traits will be more successful than their peers at surviving and/or reproducing. Provided these traits are heritable, meaning that they have a genetic basis, the traits combinations which are selected for, will increase in frequency in the population. LÄS MER

  5. 9. Phylogeny, taxonomy and species delimitation of water mites and velvet mites

    Författare :Jeanette Stålstedt; Johannes Bergsten; Fredrik Ronquist; Joanna Mąkol; Ashley Dowling; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Acariformes; Parasitengona; Hydrachnidia; Trombidia; water mites; velvet mites; taxonomy; cryptic species; species delimitation; DNA; GMYC; experimental rearing; new synonyms; distribution; phylogeny; revised classification; Systematic Zoology; zoologisk systematik och evolutionsforskning;

    Sammanfattning : This study is part of the Swedish Taxonomy Initiative (STI) - one of the most ambitious all taxa biodiversity inventories in the world. One of the pillars in STI is to support taxonomic research on the most neglected taxonomic groups with the aim to lift the level of knowledge of biodiversity in the country. LÄS MER