Search for dissertations about: "populationsbiologi"

Showing result 21 - 25 of 32 swedish dissertations containing the word populationsbiologi.

  2. 21. 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

  4. 22. Uncovering the Past through ancient DNA : The Fate and Legacy of the last hunter-gatherers in Western Europe and Northwestern Africa

    Author : Luciana G. Simões; Mattias Jakobsson; Torsten Günther; Cristina Valdiosera; Emma Svensson; Martin Sikora; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; human evolution; archaeogenomics; ancient DNA; population genetics; hunter-gatherer; Populationsbiologi; Population Biology; Genetik; Genetics;

    Abstract : The genetic analysis of ancient human remains has revolutionized the study of human history, opening a direct window onto the demographic and evolutionary events that shaped our species' past. I use state-of-the-art ancient DNA methodologies, from sample collection and DNA extraction to data analysis, to study the ancient past of the western Mediterranean region, where climate does not favour DNA preservation. READ MORE

  5. 23. Trade-off between starvation and predation : Weight-watching in Yellowhammers

    Author : Ineke T. van der Veen; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; populationsbiologi; Population Biology;

    Abstract : In this thesis I show that captive yellowhammers (Emberiza citrinella) strategically adjusted their level of body mass and diurnal trajectory of mass increase to experimentally increased predation risk. During winter, small birds need large fat reserves to survive the night. Therefore, they build up fat reserves every day. READ MORE

  6. 24. Cooperative Breeding in the Southern Anteater-Chat : Sexual Disparity, Survival and Dispersal

    Author : Jonathan Barnaby; Jan Ekman; Anssi Laurila; Rita Covas; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Southern anteater-chat; Myrmecocichla formicivora; cooperative breeding; social evolution; behavioural ecology; delayed dispersal; family living; Africa; Biologi med inriktning mot populationsbiologi; Biology with specialization in Population Biology;

    Abstract : Group-living sets the scene for complex social behaviours such as cooperative breeding, and exploring the factors that shape group-living is crucial in understanding these behaviours. This thesis explores the ecology of a population of the facultative cooperative breeding southern anteater-chat (Myrmecocichla formicivora), a group-living bird species endemic to southern Africa. READ MORE

  7. 25. European Black Grouse : MHC Genetic Diversity and Population Structure

    Author : Tanja Strand; Jacob Höglund; Helena Westerdahl; David S. Richardson; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Major Histocompatibility Complex; BLB; balancing selection; concerted evolution; bottleneck; fragmentation; 3 UTR; Biologi med inriktning mot populationsbiologi; Biology with specialization in Population Biology;

    Abstract : Black grouse Tetrao tetrix is a bird species composed of large, continuous as well as severely reduced and fragmented populations, making it an optimal species to investigate how genetic diversity is affected by habitat fragmentation. I have focused on genetic diversity in the Major Histocompatibility Complex (MHC) to measure the ability of the black grouse to respond to environmental changes. READ MORE