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Visar resultat 1 - 5 av 286 avhandlingar som matchar ovanstående sökkriterier.
1. Genome Evolution and Niche Differentiation of Bacterial Endosymbionts
Sammanfattning : Most animals contain chronic microbial infections that inflict no harm on their hosts. Recently, the gut microflora of humans and other animals have been characterized. However, little is known about the forces that shape the diversity of these bacterial communities. LÄS MER
2. Causes and consequences of niche differentiation between color morphs of pygmy grasshoppers
Sammanfattning : In this thesis, I used the color polymorphic pygmy grasshopper, Tetrix subulata, as a model system in order to investigate the degree of niche differentiation between alternative color morphs that are present within a single population. First, I hypothesized that individuals belonging to different color morphs differ in their innate food preference due to somewhat dissimilar physiology, and in their actual food consumption due in part to differential habitat use. LÄS MER
3. Ecological niche dynamic, lessons from plankton
Sammanfattning : Abiotic conditions shape biological communities around the globe. Through spatial and temporal heterogeneity, environments impact plankton physiology, phenology and distribution. LÄS MER
4. Evolutionary ecology of arctic char (Salvelinus alpinus (L.)) : Intra- and interspecific interactions in circumpolar populations
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
5. Species interactions in streams - effects of predation, competition and ecosystem properties
Sammanfattning : Stream ecosystems are dynamic and they have an inherent environmental variability. Organisms that live in streams are adapted to the continuously changing environment and the presence or absence of species are determined by their environmental requirements, while abundance is most often affected by interactions, such as competition and predation, with other species that are found in the same habitat. LÄS MER