Sökning: "gradual evolution"

Visar resultat 16 - 20 av 55 avhandlingar innehållade orden gradual evolution.

  1. 16. Evolving ecological communities in changing environments

    Författare :Jacob Johansson; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; adaptive dynamics; competition; community evolution; ecological communities; environmental change; evolutionary branching;

    Sammanfattning : This thesis consists of theoretical studies of the evolutionary consequences of environmental change in ecological communities. Paper I and II are concerned with the origin of diversity, i.e. how a single lineage can split into two, under the influence of selection induced by competitive interactions (evolutionary branching). LÄS MER

  3. 17. Splitting the sexes : The birth and senescence of sex chromosomes

    Författare :Aivars Cirulis; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sex chromosome; Sexual conflict; Macrostomum lignano; Experimental evolution; Genomics of sex;

    Sammanfattning : The evolution of gonochorism from hermaphroditism can be gradual by increasing investment in one sex role while decreasing in the other, or rapid through the fixation of sex-role sterility mutations, eventually leading to the evolution of sex chromosomes. It is expected that the transition will involve a temporary state of gynodioecy or androdioecy as the mutations are not expected to take place at the same time. LÄS MER

  4. 18. Lokal forskningspolitik : Institutionell dynamik och organisatorisk omvandling vid Lunds universitet 1980-2005

    Författare :Fredrik Melander; Statsvetenskapliga institutionen; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Mode 2; post-academic science; Triple Helix; technology transfer; governance; research organization; the Entrepreneurial University; research policy; institutional evolution; Lund University; institutional theory; science dynamics; CUDOS; Political and administrative sciences; Statsvetenskap; förvaltningskunskap;

    Sammanfattning : In the wake of an emerging knowledge society, universities around the world have come under severe institutional pressure from changing national research policies, financing organizations´ new strategies and turbulent research dynamics. This study examines how Lund University in Sweden manages these institutional pressures. LÄS MER

  5. 19. The high Arctic summer aerosol : Size, chemical composition, morphology and evolution over the pack-ice

    Författare :Evelyne Hamacher-Barth; Caroline Leck; Stephan Weinbruch; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Arctic; aerosol; marine gel; electron microscopy; EDX-spectroscopy; chemical composition; morphology; size distribution; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

    Sammanfattning : Aerosol particles, especially in the high Arctic are still not very well represented in climate models. Particle size and number concentrations are strongly under-predicted and temporal variations of aerosol composition and size are still not very well understood, mainly due to the sparsity of observations. LÄS MER

  7. 20. Latest Miocene – Early Pliocene Paleoclimate and Phytoplankton Productivity

    Författare :Boris-Theofanis Karatsolis; Jorijntje Henderiks; Luc Beaufort; Uppsala universitet; []
    Nyckelord :Late Miocene; early Pliocene; IODP; paleoclimate; basin evolution; phytoplankton; paleoproductivity; Milankovitch cycles; Earth Science with specialization in Historical Geology and Palaeontology; Geovetenskap med inriktning mot historisk geologi och paleontologi;

    Sammanfattning : Paper IPre-Quaternary paleoclimate studies in Australia mainly focus on terrestrial records from the southeastern part of the continent. IODP Expedition 356 drilled on the northwestern Australian shelf, yielding Miocene-Pleistocene paleoclimate records in an area where climate archives are scarce. LÄS MER