Search for dissertations about: "reproductive characters"

Showing result 1 - 5 of 20 swedish dissertations containing the words reproductive characters.

2. 1. Genetic variation and population differentiation in the forest herb Lathyrus vernus (Fabaceae)

   Author : Katarina Schiemann; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; chemotaxonomy. Physiology of nonvascular plants; Systematisk botanik; taxonomi; morfologi; kemotaxonomi. Växters fysiologi inte kärlväxter .; taxonomy; morphology; phytogeography; inbreeding depression; Systematic botany; small population size; marginality; reproductive characters; leaflet shape; allozymes; Lathyrus vernus; genetic variation;

   Abstract : In the present thesis, I investigated patterns of genetic variation in the forest herb Lathyrus vernus (Fabaceae), using plant material from different-sized populations representing three geographically separated regions: central Europe, southern and central Sweden. My studies included presumably neutral or weakly selected characters (allozymes and leaflet shape) as well as characters that should be under strong directional selection (e. READ MORE

4. 2. The evolutionary ecology of plant reproductive diversity and floral signals : Mating system and floral scent in Arabis alpina

   Author : Hampus Petrén; Biodiversitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Arabis alpina; floral scent; intraspecific variation; mating system; parental conflict; phenotypic plasticity; phenotypic selection; reproductive isolation; speciation; volatile organic compound VOC ;

   Abstract : Flowering plants display an extraordinary floral- and reproductive diversity. Variation in the size, shape, colour and scent of flowers, and in systems and strategies of mating, is ubiquitous in comparisons of different species, but also exists among different conspecific populations. READ MORE

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

   Author : Tina Nilsson; Göran Arnqvist; David Hosken; Umeå universitet; []
   Keywords : 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;

   Abstract : 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. READ MORE

6. 4. Genetics and the Origin of Two Flycatcher Species

   Author : Thomas Borge; Glenn-Peter Saetre; Staffan Bensch; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; reinforcement; reproductive isolation; Z chromosome; hybridization; mate-choice; single nucleotide polymorphism; sequence variation; sexual selection; recombination; Biologi; Biology; Biologi;

   Abstract : In this thesis, different genetic tools are used to investigate pre- and postzygotic barriers to gene exchange and their role in speciation in the pied flycatcher (Ficedula hypoleuca) and the collared flycatcher (F. albicollis). This species complex consists of four genetically distinct clades that apparently diverged in allopatry (I). READ MORE

7. 5. Postmating Sexual Selection and its Role in Population Divergence in Beetles

   Author : Claudia Fricke; Göran Arnqvist; David Hosken; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; Callosobruchus maculatus; postmating sexual selection; speciation; laboratory selection experiment; divergence; Biologi; Biology; Biologi;

   Abstract : Speciation is the process describing the formation of new species and is at the heart of evolutionary biology. According to the biological species concept only reproductively isolated forms are regarded good species. This thesis aims at identifying evolutionary processes that cause population divergence and, ultimately, speciation. READ MORE