Sökning: "niche breadth"

Hittade 3 avhandlingar innehållade orden niche breadth.

  1. 1. Dynamics of omnivorous crayfish in freshwater ecosystems

    Författare :Karin Olsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; crayfish; freshwater ecosystems; niche width; growth rate; stable isotope analysis; recruitment; RNA:DNA analysis; Ecology; food availability and quality; trophic position; population dynamics;

    Sammanfattning : In this thesis I examine the dynamics of crayfish in streams and lakes. I have studied the influence of abiotic and biotic factors on abundance, growth, trophic position, niche breadth, and recruitment of crayfish, by conducting field studies, an outdoor channel experiment and timeseries analysis. LÄS MER

  3. 2. 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

  4. 3. Ecology and evolution of genetic and phenotypic variation in fritillary butterflies

    Författare :Daniela Polic; Anders Forsman; Marjo Saastamoinen; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Evolutionary Biology; Evolutionsbiologi;

    Sammanfattning : Understanding how eco-evolutionary processes and environmental variation shape different dimensions of biodiversity is a major goal in evolutionary biology and ecology, and essential for the successful protection of biological variation. In this thesis, I used fritillary butterflies as model organisms to explore and further understand the origin and dynamics of genetic and phenotypic variation at different hierarchical levels of organisation and across different spatial scales. LÄS MER