Sökning: "ekologi och evolution"

Visar resultat 1 - 5 av 169 avhandlingar innehållade orden ekologi och evolution.

  1. 1. Genomic and morphological diversity of marine planktonic diatom-diazotroph associations : a continuum of integration and diversification through geological time

    Författare :Andrea Caputo; Rachel Ann Foster; Monika Quinones Winder; Ramon Massana; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; phytoplankton; diatoms; cyanobacteria; diazotrophs; symbiosis; evolution; phylogenetics; confocal microscopy; qPCR; CARD-FISH; tropics; sub-tropics; Marine Ecology; marin ekologi;

    Sammanfattning : Symbioses between eukaryotes and nitrogen (N2)-fixing cyanobacteria (or diazotrophs) are quite common in the plankton community. A few genera of diatoms (Bacillariophyceae) such as Rhizosolenia, Hemiaulus and Chaetoceros are well known to form symbioses with the heterocystous diazotrophic cyanobacteria Richelia intracellularis and Calothrix rhizosoleniae. LÄS MER

  3. 2. Polyandry and the evolution of reproductive divergence in insects

    Författare :Tina Nilsson; Göran Arnqvist; David Hosken; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Bruchidae; cryptic female choice; multiple mating; sexual conflict; sexually antagonistic coevolution; sexual selection; speciation; sperm competition; Tenebrionidae; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : Multiple mating by females is common in nature. Yet, the evolution and maintenance of polyandry remains a bit of an evolutionary puzzle. It was my aim in this thesis to reach a greater understanding of this phenomenon as well as to investigate the consequences of polyandry on the evolution of reproductive divergence in insects. LÄS MER

  4. 3. Ecology and Evolution of Adaptive Morphological Variation in Fish Populations

    Författare :Richard Svanbäck; Peter Eklöv; Lennart Persson; Beren Robinson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; competition; functional morphology; individual specialization; inter-individual variation; intra-population variation; morphological variation; ontogeny; Perca fluviatilis; perch; phenotypic plasticity; predation; trade-offs; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : The work in this thesis deals with the ecology and evolution of adaptive individual variation. Ecologists have long used niche theory to describe the ecology of a species as a whole, treating conspecific individuals as ecological equivalent. LÄS MER

  5. 4. 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. 5. Mapping incomplete relational data : networks in ecology & evolution

    Författare :Daniel Edler; Martin Rosvall; Alexandre Antonelli; Renaud Lambiotte; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; network science; information theory; map equation; community detection; biogeography; evolution;

    Sammanfattning : We live in an interconnected world full of complex systems that cannot be understood simply by analyzing their components. From how genes regulate biological functions to the distribution of life on Earth, we need methods that can analyze systems as a whole. LÄS MER