Sökning: "incomplete lineage sorting"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden incomplete lineage sorting.

  1. 1. Disentangling the Reticulate History of Polyploids in Silene (Caryophyllaceae)

    Författare :Magnus Popp; Bengt Oxelman; Magnus Lidén; Jeff J. Doyle; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Silene; Sileneae; polyploidy; low copy nuclear DNA; RNA polymerase; RPA2; RPB2; RPD2; internal transcribed spacer; rps16; psbE-petL; concerted evolution; reticulate evolution; lineage sorting; Biologi; Biology; Biologi;

    Sammanfattning : DNA sequences from the rps16 intron and the psbE-petL spacer from the chloroplast genome, the ribosomal nuclear ITS region, and introns from the low copy nuclear genes RPA2, RPB2, RPD2a and RPD2b, are in different combinations used to infer phylogenetic relationships in Sileneae (Caryophyllaceae). Used in concert, the biparentally inherited nuclear regions are useful to distinguish between paralogy due to allopolyploidy and single gene duplications, respectively, because the latter are not expected to give rise to repeated phylogenetic patterns in potentially unlinked sequence regions. LÄS MER

  2. 2. Next-generation Molecular Systematics and Evolution: insights into Medicago

    Författare :Filipe de Sousa; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phylogeny; incomplete lineage sorting; paralogy; hybridisation; Medicago;

    Sammanfattning : Evolutionary relationships among species have in recent years been inferred using DNA sequences from specific genes and represented by tree diagrams (phylogenies). However, the signal contained in different genes can produce conflicting sets of relationships – i.e., gene tree incongruence. LÄS MER

  3. 3. Phylogeny and topological incongruence in the Rubioideae (Rubiaceae)

    Författare :Olle Thureborn; Catarina Rydin; Sylvain G. Razafimandimbison; Niklas Wikström; Michael D. Pirie; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Anthospermeae; cytonuclear discordance; gene trees; incomplete lineage sorting; incongruence; mitochondrial genome; nuclear genome; phylogenomics; phylogeny; plastid genome; Rubiaceae; Rubioideae; species trees; Plant Systematics; växtsystematik;

    Sammanfattning : The work with this thesis has focused on evolutionary relationships in the Rubioideae, the most species-rich subfamily of the large and diverse coffee family (Rubiaceae). Despite considerable efforts during the last decades, uncertainty regarding several relationships in this group has remained, either as a result of unconvincing statistic support, incongruent results, or insufficient taxon sampling. LÄS MER

  4. 4. Bridging the past to the present: investigating species boundaries with herbarium specimens and next-generation-sequencing. A case study of circumpolar Silene sect. Physolychnis

    Författare :Anne-Sophie Quatela; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; allele phasing; Bayesian inference; herbarium specimen; long read sequencing; multispecies coalescent; Silene; systematics; target capture; species complexes;

    Sammanfattning : During the recent decades, genetic information enclosed in herbarium collections have been partly revealed, largely due to the fast-moving high-throughput sequencing technologies. However, the genetic outcome from herbarium material is limited by its degradation over time, often worsened by certain preservation methods. LÄS MER

  5. 5. The evolution of flat periwinkles Littorina fabalis and L. obtusata emhasizing mitochondrial introgression and restricted recombination

    Författare :Petri Kemppainen; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Speciation; Local adaptations; Ecotypes; Mitochondrial DNA; Introgression; Restricted recombination; Positive selection; Inversions; Chromosomal rearrangements;

    Sammanfattning : The evolution of species takes in general very long time and different mechanisms are likely to operate during the various stages of this process. Accordingly speciation should be studied at different levels of species divergence. LÄS MER