Sökning: "phylogenetic network"
Visar resultat 1 - 5 av 17 avhandlingar innehållade orden phylogenetic network.
1. Optimal and Hereditarily Optimal Realizations of Metric Spaces
Sammanfattning : This PhD thesis, consisting of an introduction, four papers, and some supplementary results, studies the problem of finding an optimal realization of a given finite metric space: a weighted graph which preserves the metric's distances and has minimal total edge weight. This problem is known to be NP-hard, and solutions are not necessarily unique. LÄS MER
2. Disentangling Lecania
Sammanfattning : This thesis focuses on phylogenetic, taxonomic, ecological, and conservation aspects of the crustose lichen genus Lecania (Ramalinaceae, lichenized Ascomycota). Lecania has previously been defined on basis of relatively few morphological characters, and the genus had never been treated in molecular phylogenies. LÄS MER
3. A forest dark : an evolutionary history of Norway spruce
Sammanfattning : Embedded within the relationships among species is a dense forest of gene trees, each with a potentially unique and discordant history. Such widespread genealogical heterogeneity is expected, but embracing this hierarchy of discordance while reconstructing the histories of populations and species remains a major challenge. LÄS MER
4. Phylogenetic Inference and Allopolyploid Speciation - A Study of Silene section Physolychnis
Sammanfattning : The major theme of this thesis is allopolyploidization, with focus on Silene section Physolychnis. The evolutionary history of an allopolyploid species can be established by inferring the sister relationships of the homoeologous sequences from low copy nuclear markers. LÄS MER
5. Phylogenetic perspective on host plant use, colonization and speciation in butterflies
Sammanfattning : 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. LÄS MER