Sökning: "Phenotypic selection"

Visar resultat 1 - 5 av 157 avhandlingar innehållade orden Phenotypic selection.

1. 1. Evolutionary Ecology of Floral Traits in Fragrant Orchids

   Författare :Elodie Chapurlat; Nina Sletvold; Jon Ågren; Magne Friberg; Kathleen Kay; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; agents of selection; diurnal and nocturnal pollination; divergent selection; field experiment; floral evolution; floral scent; Gymnadenia conopsea; Gymnadenia densiflora; Orchidaceae; phenotypic selection; pollinator-mediated selection; spatial variation; scent rhythm;

   Sammanfattning : Why are flowers so diverse? Much of floral evolution is thought to be driven by pollinator-mediated selection. However, the connection between macroevolutionary patterns of floral diversity and microevolutionary processes remains poorly understood. In this thesis, I have used the fragrant orchids Gymnadenia conopsea s.s. LÄS MER

3. 2. Pollen Competition as a Target for Sexual Selection in Plants

   Författare :Åsa Lankinen; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sexual selection; Pollen tube growth rate; Pollen selection models; Pollen interactions; Pollen competition; Plants; Phenotypic plasticity; Non-random mating; Genotype by environment interactions; Mate choice; Viola tricolor.; Plant ecology; Växtekologi;

   Sammanfattning : According to the theory of sexual selection, traits can evolve because they confer a mating advantage in competition with members from the same sex. In animals, sexual selection is considered as an important evolutionary force. In this thesis I have investigated the potential for sexual selection in plants. LÄS MER

4. 3. The Interplay Between Selection And Constraints On Adaptive Divergence And Phenotypic Evolution

   Författare :Fabrice Eroukhmanoff; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Selection; Constraints; Adaptive Divergence; G-matrix; Gene Flow.; Speciation;

   Sammanfattning : Under natural or sexual selection, individuals with advantageous traits or combinations of traits will be more successful than their peers at surviving and/or reproducing. Provided these traits are heritable, meaning that they have a genetic basis, the traits combinations which are selected for, will increase in frequency in the population. LÄS MER

5. 4. Haploid selection in animals : Exploring the fitness consequences and underlying mechanisms

   Författare :Ghazal Alavioon; Simone Immler; Tommaso Pizzari; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; sperm; evolution; haploid selection; reproductive aging; fitness;

   Sammanfattning : A consequence of sexual reproduction in eukaryotes is the evolution of a biphasic life cycle with alternating diploid and haploid gametic phases. While our focus in evolutionary biology is on selection during the diploid phase, we know relatively little about selection occurring during the haploid gametic stage. LÄS MER

7. 5. Evolutionary consequences of sex-specific selection

   Författare :Josefine Stångberg; Elisabeth Bolund; Elina Immonen; Jennifer Perry; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Caenorhabditis remanei; Callosobruchus maculatus; sex-specific selection; sexual selection; experimental evolution; intralocus sexual conflict; life history evolution; sexual dimorphism; trade-offs; Quantitative genetics;

   Sammanfattning : Sex-specific selection is widespread, evident by the evolution of sexual dimorphism in many traits in sexually reproducing taxa. The reason why the sexes may experience selection that differs in direction or magnitude is often linked to the reproductive strategies associated with the sex-specific reproductive physiology. LÄS MER