Search for dissertations about: "Rana temporaria"
Showing result 1 - 5 of 11 swedish dissertations containing the words Rana temporaria.
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1. Effects of Agriculture on Abundance, Genetic Diversity and Fitness in the Common Frog, Rana temporaria
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
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2. Evolutionary ecology of ultraviolet-B radiation stress tolerance in amphibians
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
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3. Adaptation Along Environmental Gradients: an Evaluation of Physiological Mechanisms and Ecological Constraints
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
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4. Endocrine Disruption in Amphibians : Developmental Effects of Ethynylestradiol and Clotrimazole on the Reproductive System
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
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5. Phenotypic plasticity and local adaptation in island populations of Rana temporaria
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