Search for dissertations about: "Rana temporaria"

Showing result 1 - 5 of 10 swedish dissertations containing the words Rana temporaria.

  1. 1. Effects of Agriculture on Abundance, Genetic Diversity and Fitness in the Common Frog, Rana temporaria

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Markus Johansson; Uppsala universitet.; [2004]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; agriculture; agrochemicals; amphibians; effective population size; genetic diversity; genetic structure; hierarchical sampling; microsatellites; Rana temporaria; Biologi; NATURAL SCIENCES Biology; NATURVETENSKAP Biologi;

    Abstract : The aims of this thesis were to evaluate the effects of agriculture on amphibians in terms of (i) population genetic consequences of agriculture-induced spatial changes of the landscape and (ii) local adaptation and tolerance to frequently used agrochemicals. The study was performed using the common frog Rana temporaria as a model. READ MORE

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

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Maarit Pahkala; Uppsala universitet.; [2001]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; amphibians; anomalies; embryonic development; geographic variation; growth; Rana arvalis; Rana temporaria; survival; UV-B radiation; Utvecklingsbiologi; NATURAL SCIENCES Biology Organism biology Developmental biology; NATURVETENSKAP Biologi Organismbiologi 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

  3. 3. Adaptation Along Environmental Gradients: an Evaluation of Physiological Mechanisms and Ecological Constraints

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Beatrice Lindgren; Uppsala universitet.; [2007]
    Keywords : Biology; Rana temporaria; latitudinal clines; growth rate; growth efficiency; SMR; predation; competition; trade-off; Biologi;

    Abstract : For ectotherms living in seasonal environments, time available for development and growth is often constrained by the length of the growth season. Declining season length towards higher latitudes often select for latitudinal clines in development and growth rates, exhibiting increasing growth and developmental rates towards the north. READ MORE

  4. 4. Endocrine Disruption in Amphibians Developmental Effects of Ethynylestradiol and Clotrimazole on the Reproductive System

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Irina Gyllenhammar; Uppsala universitet.; [2008]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Test system; Xenopus tropicalis; Rana temporaria; sex ratio; sex differentiation; fertility; aromatase; ovary; testis; oviduct; NATURAL SCIENCES Biology; NATURVETENSKAP Biologi;

    Abstract : Amphibian populations are declining world-wide and one of the suggested reasons is environmental pollutants. Studies of long-term effects on the reproductive system in frogs following larval exposure to environmental pollutants are scarce. It is therefore important to develop methods to study developmental reproductive toxicity in amphibians. READ MORE

  5. 5. Phenotypic plasticity and local adaptation in island populations of Rana temporaria

    University dissertation from Umeå : Department of Ecology & Environmental Science, Umeå University

    Author : Martin Lind; Umeå universitet.; [2009]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Costs of plasticity; Developmental threshold; FST; Local adaptation; Phenotypic plasticity; Pool drying; QST; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology Freshwater ecology; NATURVETENSKAP Biologi Terrestrisk; limnisk och marin ekologi Limnisk ekologi; zooekologi; Animal Ecology;

    Abstract : Phenotypic plasticity is the ability of a genotype to express different phenotypes in different environments. Despite its common occurrence, few have investigated differences in plasticity between populations, the selection pressures responsible for it, and costs and constraints associated with it. READ MORE