Search for dissertations about: "clinal variation"

Showing result 1 - 5 of 6 swedish dissertations containing the words clinal variation.

2. 1. Conifer Evolution, from Demography and Local Adaptation to Evolutionary Rates : Examples from the Picea genus

   Author : Jun Chen; Martin Lascoux; Ulf Lagercrantz; Matt Olson; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Speciation; Demographics; clinal variation; convergent evolution; transcriptome; small regulatory RNA; Biologi med inriktning mot evolutionär funktionsgenomik; Biology with specialization in Evolutionary Functional Genomics; Biology with specialization in Evolutionary Genetics; Biologi med inriktning mot evolutionär genetik;

   Abstract : Evolutionary process can be inferred at three different levels: the species level, the population level and the molecular level. In this thesis, I applied approaches at these three levels and aimed to get a comprehensive picture of conifer evolution, from speciation and demography to geographic variation and local adaptation, and then to the molecular evolution of proteins and small regulatory RNAs. READ MORE

4. 2. Population differentiation in Lythrum salicaria along a latitudinal gradient

   Author : Katarina Olsson; Jon Ågren; Susan Kalisz; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; additive genetic variance; clinal variation; evolutionary constraints; G matrix; genetic correlation; natural selection; pollen limitation; population differentiation; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

   Abstract : In this thesis, quantitative genetic approaches, common-garden experiments, and field studies were combined to examine patterns of population differentiation and the genetic architecture of characters of putative adaptive significance in the widely distributed perennial herb Lythrum salicaria. In this work, I (1) documented patterns of population differentiation in phenology, life-history, and morphology along latitudinal gradients at different geographical scales, (2) investigated the genetic architecture of phenology, flower morphology, and inflorescence size, and (3) combined estimates of phenotypic selection in the field with information on the genetic variance-covariance matrix (G) to examine potential constraints to adaptive evolution. READ MORE

5. 3. Comparative morphological studies of fossil and living plane trees (Platanaceae) and oaks (Quercus): taxonomy, ecology, evolution

   Author : Georg Florian Tschan; Thomas Denk; Ove Eriksson; Bertil Ståhl; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Platanaceae; Platanus; Credneria; Quercus; Galliferae; leaf architecture; epidermal anatomy; comparative morphology; character variation; variability; sample size; diversity patterns; species concepts; ecology; biogeography; evolution; plant fossils; Plant Ecology; växtekologi;

   Abstract : Morphological characters are essential for flowering plant identification, but also provide information about diversity patterns and ecological adaptation. In woody plant species, characters of the leaf are among the most useful and can be examined on fossils as well. 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. Systematics, phylogeography and polyploid evolution in the Dactylorhiza maculata complex (Orchidaceae)

   Author : David Ståhlberg; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; ITS; morphometry; taxonomy; Systematic botany; Växtekologi; Plant ecology; vegetation analysis; recombination; polyploidy; plastid DNA; niche differentiation; chemotaxonomy. Physiology of nonvascular plants; morphology; phytogeography; hybrid zone; glacial refugia; Dactylorhiza; flow cytometry; Systematisk botanik; taxonomi; morfologi; kemotaxonomi. Växters fysiologi inte kärlväxter .;

   Abstract : The aim of this thesis was to investigate and describe different aspects of variation in the Dactylorhiza maculata complex and to relate the variation patterns to underlying biological processes such as Quaternary migration history, hybridization and polyploid evolution. The variation patterns were analysed at various geographic levels using molecular markers (plastid DNA and ITS of nrDNA), cytological data, morphometry and ecological data. READ MORE