Search for dissertations about: "speciation"

Showing result 16 - 20 of 281 swedish dissertations containing the word speciation.

  2. 16. Genetic Adaptation and Speciation in Darwin’s Finches and Atlantic Herring

    Author : Fan Han; Leif Andersson; Kjetill Sigurd Jakobsen; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Darwin s finches; Atlantic herring; Population genetics; Evolution; Ecological adaptation; Speciation; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology; Bioinformatics; Bioinformatik;

    Abstract : Natural selection acts on existing genetic variation to drive genetic adaptation of organisms to various ecological niches. Interaction between closely related populations, through processes such as competition and hybridization, may either lead to their divergence or population fusion, which has consequences for adaptation and the formation of species. READ MORE

  4. 17. Speciation - What Can be Learned from a Flycatcher Hybrid Zone?

    Author : Chris Wiley; Anna Qvarnström; Lars Gustafsson; Roger Butlin; Uppsala universitet; []
    Keywords : Biology; speciation; reinforcement; fitness; postzygotic isolation; asymmetrical hybridization; hybrid zone; species recognition; mate choice; sexual selection; direct benefits; parasite resistance; delayed plumage maturation; Ficedula hypoleuca; Ficedula albicollis; flycatcher; Biologi;

    Abstract : Studies of hybrid zones offer important insights into the process of speciation. Much of the knowledge to be gained is dependent on an accurate estimation of the strength of pre- and post-zygotic isolation between hybridizing taxa. My results demonstrate that hybridization can variously affect different components of fitness. READ MORE

  5. 18. Origin and mobility of major and key trace elements (Cs, YREEs) in fracture groundwater in the upper 1.2 kilometres of coastal granitoids : Implications for future repositories of spent nuclear fuel

    Author : Frédéric A. Mathurin; Mats E. Åström; Marcus Laaksoharju; Birgitta Kalinowski; Niklaus Waber; Linnéuniversitetet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; fracture groundwater; groundwater mixing; seawater intrusion; water-rock interactions; cation exchange; Cesium; Rare Earth Elements; colloidal speciation; humic substances; dual porosity; inverse modelling; Äspö HRL; Laxemar; Forsmark; eaux de fractures; mélange d eaux; intrusion d eau de mer; interactions eau-roche; échanges cationiques; Césium; Elements Terres Rares; spéciation colloïdale; substances humiques; double porosité; modélisation inverse; Äspö HRL; Laxemar; Forsmark; sprickvatten; grundvatten mixing; havsvattenintrusion; vatten-berg interaction; katjonbyte; cesium; sällsynta jordartsmetaller; kollidal speciation; humusämnen; dual porositet; invers modellering; Äspölaboratoriet; Äspötunneln; Laxemar; Forsmark; Miljövetenskap; Environmental Science;

    Abstract : This thesis focuses on the chemical and isotopic features of groundwater residing in the upper 1.2 km of sparsely fractured crystalline bedrock of the Baltic Shield. READ MORE

  6. 19. Inferring demographic history and speciation of grouse using whole genome sequences

    Author : Radoslav Kozma; Jacob Höglund; Jeff A. Johnson; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Demographic history; speciation; effective population size; adaptation; willow grouse; red grouse; black grouse; rock ptarmigan; Tetraoninae; conservation genetics; climate change; PSMC; species distribution modelling; FOXP4; Agouti;

    Abstract : From an ecological perspective, knowledge of demographic history is highly valuable because population size fluctuations can be matched to known climatic events, thereby revealing great insight into a species’ reaction to past climate change. This in turn enables us to predict how they might respond to future climate scenarios. READ MORE

  7. 20. Phylogenetic perspective on host plant use, colonization and speciation in butterflies

    Author : Elisabet Weingartner; Sören Nylin; Niklas Wahlberg; Felix Sperling; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Oscillation hypothesis; speciation; Polygonia; Celastrina; Pararge; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; zoologisk ekologi; Animal Ecology;

    Abstract : In this thesis we have studied speciation in three butterfly genera Polygonia (Nymphalidae, Nymphalini), Pararge (Nymphalidae, Satyrinae) and Celastrina (Lycaenidae: Polyommatinae). In the first paper a dated phylogeny, based on molecular data, of Polygonia was constructed. We found strong conflict between the nDNA and mtDNA datasets. READ MORE