Sökning: "cost of reproduction"

Visar resultat 16 - 20 av 47 avhandlingar innehållade orden cost of reproduction.

  1. 16. Evaluating effects of low concentrations of oil in marine benthic communities

    Författare :Fredrik Lindgren; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; PAHs; community response; microbial community; oil; meiofauna;

    Sammanfattning : Large anthropogenic discharges of oil annually enter the marine environment, in the magnitude from large scale discharges to minor leakage, caused by ship collision accidents or seepage from urban areas. Possible detrimental environmental effects from these discharges differ, from acute lethal to chronic sub-lethal. LÄS MER

  3. 17. Evolutionary ecology of arctic char (Salvelinus alpinus (L.)) : Intra- and interspecific interactions in circumpolar populations

    Författare :Johan Hammar; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Arctic char; Salvelinus alpinus; biogeography; niche; life history; population ecology; intra- and interspecific interactions; cannibalism; competition; landlocked; marginal populations; species border; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

    Sammanfattning : This thesis examines a suite of ecological and genetic mechanisms influencing the fundamental and realized niche borders of European and North American populations of the Arctic char (Salvelinus alpinus (L.)) species complex in allopatry as well as in sympatry with brown trout (Salmo trutta) or brook trout (Salvelinus fontinalis). LÄS MER

  4. 18. The balance between sex and asex: evolutionary genetic studies of reproductive variation in Allium vineale

    Författare :Alf Ceplitis; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ontogeny; growth animal ; Allium vineale; Development biology; evolution; sexual reproduction; reproductive systems; embryology; Utvecklingsbiologi; ontogeni; embryologi; Genetics; cytogenetics; Genetik; cytogenetik;

    Sammanfattning : Evolutionary theory predicts a disadvantage to sexual reproduction. This manifests itself either by the higher growth rate of asexual females in a dioecious species, or by the higher transmission rate of a gene conferring asexual female function to its carriers in a hermaphrodite species. LÄS MER

  5. 19. Colour Calibration of Trichromatic Capturing Devices

    Författare :Mattias Andersson; Olle Inganäs; Nir Tessler; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polymer; fullerene; field-effect transistor; solar cell; electrical transport; mobility; Physics; Fysik;

    Sammanfattning : In a time where there is an increasing demand for easily accessible and up-to-date information, digital printing has become a link between traditional printed media and electronic media. Over the last years, applications such as variable data printing, personalised printing and print on demand have changed the way in which printed matter is produced and handled. LÄS MER

  7. 20. Phenotypic responses of zooplankton to variable conditions

    Författare :Marcus Lee; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Multiple threats; Plasticity; Risk-Spreading; sexual conflict; ultraviolet radiation; Daphnia; Copepods;

    Sammanfattning : Organisms are continually challenged by multiple threats in the environment, and such threats are seldom constant in either time or space. Therefore, organisms must maintain physiological, behavioural, morphological and life- history adaptations across environments to prevent reductions in fitness. LÄS MER