Sökning: "character evolution"

Visar resultat 1 - 5 av 87 avhandlingar innehållade orden character evolution.

  1. 1. Evolution and biodiversity of the Ixoroideae (Rubiaceae)

    Detta är en avhandling från Stockholm : Department of Botany, Stockholm University

    Författare :Kent Kainulainen; Stockholms universitet.; [2010]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Alberteae; character evolution; classification; Condamineeae; fruit evolution; Ixoroideae; phylogenetics; pollen presentation; Rubiaceae; systematics; taxonomy; NATURAL SCIENCES Biology Organism biology Systematics and phylogenetics; NATURVETENSKAP Biologi Organismbiologi Systematik och fylogeni; Plant Systematics; växtsystematik;

    Sammanfattning : The phylogenetic relationships within subfamily Ixoroideae of the coffee family are investigated by phylogenetic reconstruction of molecular data, including regions of the chloroplast DNA (matK, ndhF, rbcL, rps16, trnH-psbA, trnS-G, and trnT-F), and the nuclear ribosomal DNA (ITS). The evolution of morphological characters within the group are inferred, with focus on characters used in classification. LÄS MER

  2. 2. Ecology and Evolution of Resistance to Herbivory Trichome Production in Arabidopsis lyrata

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Geir Løe; Högskolan i Gävle.; Uppsala universitet.; [2006]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plant-animal interactions; herbivory; trichomes; plant resistance; plant defense; divergent selection; local adaptation; GLABROUS1; evolution; matrix population models; LTRE; NATURAL SCIENCES Biology; NATURVETENSKAP Biologi; Biology; Biologi;

    Sammanfattning : In this thesis, I examine variation in occurrence and performance of glabrous and trichome-producing plants of the perennial herb Arabidopsis lyrata. I combine field studies and genetic analysis to (1) examine the function of trichomes as a resistance character in natural populations, (2) compare the magnitude of population differentiation in trichome-production and at putatively neutral marker loci, (3) examine the molecular genetic basis of trichome-production, and (4) quantify the effects of herbivore removal on population growth and relative performance of glabrous and trichome-producing plants. LÄS MER

  3. 3. Comparative morphological studies of fossil and living plane trees (Platanaceae) and oaks (Quercus): taxonomy, ecology, evolution

    Detta är en avhandling från Stockholm : Department of Botany, Stockholm University

    Författare :Georg Florian Tschan; Stockholms universitet.; [2011]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Platanaceae; Platanus; Credneria; Quercus; Galliferae; leaf architecture; epidermal anatomy; comparative morphology; character variation; variability; sample size; diversity patterns; species concepts; ecology; biogeography; evolution; plant fossils; växtekologi; Plant Ecology;

    Sammanfattning : Morphological characters are essential for flowering plant identification, but also provide information about diversity patterns and ecological adaptation. In woody plant species, characters of the leaf are among the most useful and can be examined on fossils as well. LÄS MER

  4. 4. Selection and Floral Evolution in Platanthera bifolia and P. chlorantha (Orchidaceae)

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Johanne Maad; Uppsala universitet.; [2002]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES Biology Organism biology Developmental biology; NATURVETENSKAP Biologi Organismbiologi Utvecklingsbiologi; systematisk botanik; Systematic Botany; Developmental biology; Evolution; phenotypic selection; male function hypothesis; mating systems; floral shifts; orchids; pollination; moth pollinators; Platanthera.; Utvecklingsbiologi;

    Sammanfattning : Natural selection mediated by pollinators has influenced the evolution of floral diversity of the flowering plants (angiosperms). The scope of this thesis was to study: 1) phenotypic selection, 2) mating systems, and 3) floral shifts involved in plant speciation. Model plant species were Platanthera bifolia and P. chlorantha (Orchidaceae). LÄS MER

  5. 5. Patterns of evolution in a young species, the Baltic seaweed Fucus radicans

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Angelica Ardehed; Göteborgs universitet.; Gothenburg University.; [2015]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Marine biology; Evolution;

    Sammanfattning : To be able to interpret patterns of biodiversity it is important to understand the processes by which new species evolve and how closely related species remain reproductively isolated and ecologically differentiated. This thesis centers on the evolution of the two brown algae Fucus radicans and Fucus vesiculosus in the Baltic Sea, where Fucus radicans very recently diverged from F. LÄS MER