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Visar resultat 1 - 5 av 108 avhandlingar som matchar ovanstående sökkriterier.
1. Advances in studying the role of genetic divergence and recombination in adaptation in non-model species
Sammanfattning : Understanding the role of genetic divergence and recombination in adaptation is crucial to understanding the evolutionary potential of species since they can directly affect the levels of genetic variation present within populations or species. Genetic variation in the functional parts of the genome such as exons or regulatory regions is the raw material for evolution, because natural selection can only operate on phenotypic variation already present in the population. LÄS MER
2. Genetic variation and sexual reproduction in a moss with dwarf males, Homalothecium lutescens
Sammanfattning : Dwarf males occur in many unrelated groups of organisms. Among land plants they are unique to mosses. Moss dwarf males originate from male spores that land and germinate on the female where their final size is restricted to a few mm. Fertilization in mosses occur over short distances with swimming spermatozoids. LÄS MER
3. Genetic adaptation to soil acidification in four grasses
Sammanfattning : Soil acidification has become a source of serious concern in many parts of the world. In southern Sweden, the deposition of acidifying substances, such as nitrogen and sulphur compounds, has decreased the mean pH of forest soils by almost one unit since the 1950s. LÄS MER
4. Geographic variation in life cycles : Local adaptation and ecological genetics in a temperate butterfly
Sammanfattning : Conditions in nature change with the seasons, necessitating seasonal adaptations that synchronize the life cycles of organisms with their surroundings. Such regulatory adaptations must vary between populations to track local variation in climate and seasonality; this local adaptation is facilitated by locally specific seasonal cues, but may be hampered by gene flow and genetic history. LÄS MER
5. Population size, viability and genetic diversity in the orchid Gymnadenia conopsea
Sammanfattning : In this thesis, I combined controlled crosses with genetic and demographic data to examine how a main conservation value indicator, population size, was associated with estimates of population viability. I focused on the still common, but decreasing, perennial orchid Gymnadenia conopsea at two spatial scales—locally on the island Öland, in SE Sweden, and regionally across Scandinavia. LÄS MER