Sökning: "Population genetic"

Visar resultat 16 - 20 av 1277 avhandlingar innehållade orden Population genetic.

  1. 16. Genetic Aspects of Sexual Selection and Mate Choice in Salmonids

    Författare :Lars Forsberg; Mats Grahn; Jacob Höglund; Claus Wedekind; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; mate choice; Mhc; Major histocompatibility complex; class IIB; disassortative; assortative; microsatellite; outbreeding; supportive breeding; population; population genetics; Biologi; Biology; Biologi;

    Sammanfattning : The long-term genetic consequences of supportive breeding programs are not well understood. Nevertheless, stocking populations with hatchery-produced fish to compensate for losses of natural production are common practice, for example after constructions of hydroelectric power dams. LÄS MER

  2. 17. Population differentiation in Lythrum salicaria along a latitudinal gradient

    Författare :Katarina Olsson; Jon Ågren; Susan Kalisz; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; additive genetic variance; clinal variation; evolutionary constraints; G matrix; genetic correlation; natural selection; pollen limitation; population differentiation; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : In this thesis, quantitative genetic approaches, common-garden experiments, and field studies were combined to examine patterns of population differentiation and the genetic architecture of characters of putative adaptive significance in the widely distributed perennial herb Lythrum salicaria. In this work, I (1) documented patterns of population differentiation in phenology, life-history, and morphology along latitudinal gradients at different geographical scales, (2) investigated the genetic architecture of phenology, flower morphology, and inflorescence size, and (3) combined estimates of phenotypic selection in the field with information on the genetic variance-covariance matrix (G) to examine potential constraints to adaptive evolution. LÄS MER

  3. 18. Genetic Disequilibria and the Interpretation of Population Genetic Structure in Daphnia

    Författare :Lars M. Berg; Xavier Vekemans; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; breeding system; linkage disequilibrium; dispersal; genetic structure; Daphnia pulex; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; naturvårdsbiologi; Conservation Biology;

    Sammanfattning : Understanding the processes that shape the spatial distribution of genetic variation within species is central to the evolutionary study of diversification and demography. Neutral genetic variation reflects past demographic events as well as current demographic characteristics of populations, and the correct interpretation of genetic data requires that the relative impact of these forces can be identified. LÄS MER

  4. 19. Finding fitness : empirical and theoretical explorations of inferring fitness effects from population-level SNP data

    Författare :Bea Angelica Andersson; Xiao-Ru Wang; Åke Brännström; Tanja Slotte; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; distribution of fitness effects; site frequency spectra; missing data filtering; downsampling; imputation; sample size; population structure; inbreeding; selfing; homozygosity; Arabidopsis; Pinus; DFE-alpha; SLiM; population genomics; adaptation; biology; biologi; evolutionär genetik; evolutionary genetics; populationsbiologi; Population Biology; molekylärbiologi; Molecular Biology; Genetics; genetik;

    Sammanfattning : The distribution of fitness effects (DFE) describes the likelihood that a new mutation has a specific effect on the fitness of an individual in a given population. The shape of the DFE is a result of several factors such as population size, mating system and selective environment, and can in turn influence the evolutionary potential of a species. LÄS MER

  5. 20. From the migrations of herders and farmers to the colonial era and the modern-day : Genetic inferences on African demographic history

    Författare :Rickard Hammarén; Mattias Jakobsson; Carina Schlebusch; Torsten Günther; Luca Pagani; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; admixture; African demography; human evolutionary genetics; population structure; sex-biased admixture; Africa; population genetics; Biology with Specialisation in Human Evolution and Genetics; Biologi med inriktning mot människans evolution och genetik;

    Sammanfattning : Africa is the birthplace of the human species and home to great linguistic, cultural, and genetic diversity. Despite this, the genetics of the peoples of the continent remains understudied. In this thesis, I apply population genetic approaches, to contribute to the knowledge of human demographic history in Africa. LÄS MER