Sökning: "purging selection"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden purging selection.

  1. 1. Gene transfer by interspecific hybridization in bryophytes

    Författare :Weerachon Sawangproh; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; homozygote; heterozygote; admixture; single nucleotide polymorphism; STRUCTURE; PCoA; hybrid index; inbreeding; outbreeding; hybrid depression; heterosis; phylogeny; purging selection; genetic purging; genotype; phenotype; sympatry; allopatry;

    Sammanfattning : The role of hybridization in evolution has been debated for more than a century regarding bryophytes (mosses, liverworts, and hornworts) as well as most other organisms. Bryophytes have haplodiplontic life cycles with a dominant haploid generation. LÄS MER

  3. 2. Sexual Selection and Adaptation to Novel Environments

    Författare :Ivain Martinossi-Allibert; David Berger; Göran Arnqvist; Lukas Schärer; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sexual selection; Environmental change; Sexual conflict; Environmental stress; Adaptation; Adaptive landscape; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology;

    Sammanfattning : The work included in this thesis aims at exploring the environmental sensitivity of benefits and costs of sexual selection through a combined empirical and theoretical effort, to increase our understanding of the impact of environmental change on sexually reproducing populations.Can sexual selection promote adaptation to novel environments? Sexual selection for good genes should accelerate adaptation by granting higher reproductive success to individuals of high genetic quality. LÄS MER

  4. 3. Immunoglobulin Gene Analysis in Different B cell Lymphomas : With Focus on Cellular Origin and Antigen Selection

    Författare :Mia Thorsélius; Richard Rosenquist Brandell; Christer Sundström; Anders Rosén; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Genetics; B cell lymphoma; Immunoglobulin; V gene; somatic hypermutation; antigen selection; quantitative PCR; Genetik; Clinical genetics; Klinisk genetik;

    Sammanfattning : B cell lymphoma (BCL) comprises a biologically and clinically heterogeneous group of tumors deriving from different stages of B cell development. The immunoglobulin (Ig) variable heavy chain (VH) gene rearrangement is unique for each BCL and can be used to reveal cellular origin, to study signs of antigen selection and to quantify tumor cell load. LÄS MER

  5. 4. Island biogeography and population divergence in the Skyros wall lizard

    Författare :Anna Runemark; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Podarcis gaigeae; inbreeding; predation release; polymorphism; island gigantism; the island rule; genetic drift; sexual selection; natural selection; island biology; Evolution;

    Sammanfattning : Islands are cradles for new biodiversity and provide natural laboratories for the study of population divergence. In my thesis, I investigated the role of different evolutionary processes in the population divergence in the Skyros wall lizard (Podarcis gaigeae), a species where islet populations have strongly diverged morphologies. LÄS MER

  7. 5. The use of museum specimens in conservation genomics

    Författare :Johanna von Seth; Love Dalén; Karin Norén; Gernot Segelbacher; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; conservation genomics; museum specimens; genomic erosion; diversity; inbreeding; mutational load; genetic drift; purging; population divergence; local extinction; population decline; Sumatran rhinoceros; kakapo; arctic fox; Chatham Island black robin; Systematic Zoology; zoologisk systematik och evolutionsforskning;

    Sammanfattning : In the face of an increasing number of species being threatened by extinction, museum collections can constitute a powerful resource for acquiring genomic data of endangered taxa. By utilising datasets that combine genomes from present-day populations with those from historical timepoints, several questions relevant for conservation can be investigated. LÄS MER