Sökning: "habitat evolution"

Visar resultat 6 - 10 av 64 avhandlingar innehållade orden habitat evolution.

  1. 6. On the origin of polymorphism - consequences of competition and predation in heterogeneous environments

    Författare :Jennie Holmér; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; source-sink dynamics; predation; competition; dispersal; polymorphism; evolution; crypsis; adaptive dynamics;

    Sammanfattning : In this thesis, I have studied when an initially monomorphic population can diverge into two morphs in a heterogeneous environment. Evolution is driven by competition for resources or predation. In Paper I, we studied source-sink dynamics during evolution in an environment with two types of resource of different abundance in two habitats. LÄS MER

  3. 7. Mobility and emigration in butterflies

    Författare :Karin Enfjäll; Olof Leimar; Michel Baguette; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Keywords: conspecific density; dispersal; evolution; flight-behaviour; information; sexual conflict; social interactions; Ethology and behavioural ecology; Etologi och beteendeekologi; etologi; Ethology;

    Sammanfattning : Because of its implications for the survival of many species, dispersal plays a key role in conservation biology. A good knowledge about the different factors that influence dispersal decisions is crucial for the understanding of inter-population movements. LÄS MER

  4. 8. The evolutionary ecology of niche separation : Studies on the sympatric butterflies Leptidea sinapis and Leptidea reali

    Författare :Magne Friberg; Wiklund Christer; John N. Thompson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lepidoptera; ecological character displacement; reproductive isolation; species discrimination; habitat; host plant; life history; sexual selection; female choice; Biology; Biologi; zoologisk ekologi; Animal Ecology;

    Sammanfattning : Studies of ecology and evolution have become largely integrated, and increasing attention is paid to the role of ecology for speciation and post speciation divergence. In this thesis I have applied an in-depth approach studying the ecology of a butterfly species pair; the morphologically virtually identical sister-species, the Wood white (Leptidea sinapis) and Reál’s wood white (Leptidea reali). LÄS MER

  5. 9. Local adaptive pigmentation in Asellus aquaticus -effects of UV-radiation and predation regime

    Författare :Jonas Johansson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; damselfly; perch; UV-avoidance; isopod; anti-predator traits; evolution; selective predation; limnologi; akvatisk ekologi; Animal ecology; Djurekologi;

    Sammanfattning : Pigmentation in the freshwater isopod Asellus aquaticus differed between two habitats. Asellus were lighter pigmented in stands of submerged stonewort vegetation, than in nearby reed stands. Moreover, Asellus pigmentation became lighter with time in recently established stonewort stands. LÄS MER

  7. 10. Evolutionary ecology of newts

    Författare :Jan C. Malmgren; Hanna Kokko; Örebro universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; evolution; adaptation; amphibians; salamanders; predation; migration; sexual dimorphism; sex differences; behaviour; conservation; Biology; Biologi; Biologi med ekologisk inriktning;

    Sammanfattning : Sexual dimorphism, predator avoidance and migratory behaviour are adaptive traits that show variation at the population and species level. Such features respond to the environment in the broad sense, that is, when both abiotic and biotic components are included. LÄS MER