Search for dissertations about: "GEOGRAPHIC-VARIATION"

Showing result 1 - 5 of 14 swedish dissertations containing the word GEOGRAPHIC-VARIATION.

  2. 1. Geographic variation in life cycles : Local adaptation and ecological genetics in a temperate butterfly

    Author : Olle Lindestad; Karl Gotthard; Sören Nylin; Christopher W Wheat; Greg Ragland; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; voltinism; local adaptation; insect; life cycle; seasonality; genomics; life history; zoologisk ekologi; Animal Ecology;

    Abstract : 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. READ MORE

  4. 2. Patterns of geographic variation in Silene section Elisanthe (Caryophyllaceae): hybridization and migrational history

    Author : Louise Hathaway; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; chemotaxonomy. Physiology of nonvascular plants; phytogeography; morphology; outbreeding depression; Systematic botany; taxonomy; ITS; fitnes; inbreeding depression; AFLP; PCR-RFLP; cpDNA; gene flow; postglacial migration; geographic variation; hybridization; Silene latifolia; Silene section Elisanthe; Silene dioica; Systematisk botanik; taxonomi; morfologi; kemotaxonomi. Växters fysiologi inte kärlväxter .;

    Abstract : Large-scale patterns of genetic variation in chloroplast (cp) and nuclear DNA in the widespread European herb species Silene latifolia and S. dioica were investigated using cpPCR-RFLPs, non-coding cpDNA sequences, AFLPs and sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA). READ MORE

  5. 3. Evolutionary ecology of ultraviolet-B radiation stress tolerance in amphibians

    Author : Maarit Pahkala; Trevor Beebee; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; amphibians; anomalies; embryonic development; geographic variation; growth; Rana arvalis; Rana temporaria; survival; UV-B radiation; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; populationsbiologi; Population Biology;

    Abstract : During the last decades many amphibian species and populations have experienced declines and extinctions in different parts of the world. Anthropogenic activities are believed to account for these declines, and one of the hypothesized causes has been the increased level of ultraviolet-B (UV-B) radiation due to depletion of the stratospheric ozone layer. READ MORE

  6. 4. Ecology and evolution in a host-parasitoid system : Host search, immune responses and parasitoid virulence

    Author : Lisa Fors; Peter Hambäck; Wertheim Bregje; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Host-parasitoid interactions; Plant-herbivore interactions; Host search; Volatiles; Pheromones; Geographic variation; Cellular defence; Melanisation; Encapsulation; Asecodes; Galerucella; Plant Ecology; växtekologi;

    Abstract : In host-parasitoid systems, there is a continuous coevolutionary arms race where each species imposes a strong selection pressure on the other. The host needs to develop defence strategies in order to escape parasitism and the parasitoid must evolve counter-defence strategies in order to overcome the host’s immune defence and successfully reproduce. READ MORE

  7. 5. Geographic differentiation and population history in Silene dioica and S. hifacensis: variation in chloroplast DNA and allozymes

    Author : Ursula Malm; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; morphology; taxonomy; Systematic botany; conservation biology; endemic; chloroplast DNA; allozyme; hybridization; gene flow; geographic variation; postglacial migration; genetic diversity; Silene; phytogeography; chemotaxonomy. Physiology of nonvascular plants; Systematisk botanik; taxonomi; morfologi; kemotaxonomi. Växters fysiologi inte kärlväxter .;

    Abstract : In this thesis I used allozymes and PCR-RFLP analysis of chloroplast DNA (cpDNA) to investigate geographic differentiation within the widespread Silene dioica (L.) Clairv. (Caryophyllaceae) and the narrowly-distributed S. hifacensis Rouy ex Willk. READ MORE