Sökning: "population differentiation"

Visar resultat 1 - 5 av 350 avhandlingar innehållade orden population differentiation.

  1. 1. Population Genetic Methods and Applications to Human Genomes

    Författare :Lucie Gattepaille; Mattias Jakobsson; Kevin Thornton; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Population genetics; Human evolution; Genetic diversity; Genetic differentiation; Adaptation; Population structure; Effective population size; Biology with specialization in Evolutionary Genetics; Biologi med inriktning mot evolutionär genetik;

    Sammanfattning : Population Genetics has led to countless numbers of fruitful studies of evolution, due to its abilities for prediction and description of the most important evolutionary processes such as mutation, genetic drift and selection. The field is still growing today, with new methods and models being developed to answer questions of evolutionary relevance and to lift the veil on the past of all life forms. LÄS MER

  2. 2. Population Differentiation in Solidago virgaurea along Altitudinal Gradients

    Författare :Anna Bergsten; Jon Ågren; Staffan Karlsson; Kari Lehtilä; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; population differentiation; altitudinal gradient; plant nutrient status; resorption efficiency; resorption proficiency; flowering phenology; countergradient variation; reproductive effort; flower production; cost of reproduction; Biology; Biologi; Other biology; Övrig biologi; Ecological Botany; Ekologisk botanik;

    Sammanfattning : Altitudinal gradients offer attractive opportunities for studies of population differentiation in response to environmental heterogeneity. In this thesis, I examined population differentiation along altitudinal gradients by combining common-garden experiments with field studies and experiments in alpine, subalpine and boreal populations of the perennial herb Solidago virgaurea. LÄS MER

  3. 3. 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

  4. 4. Genomics of population decline

    Författare :Tom van der Valk; Katerina Guschanski; Aylwyn Scally; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; genetic diversity; minimal-invasive samples; population decline; inbreeding; genetic purging; eastern gorillas; Dryas monkey; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology;

    Sammanfattning : With human populations forecasted to grow in the next decades, many mammals face increasing anthropogenic threats. The consequential population declines are a precursor to extinctions, as small populations are not only more sensitive to stochastic events, but reduction in population size is generally also followed by a decrease in genetic diversity, which in turn reduces adaptive potential and fitness of the population. LÄS MER

  5. 5. Morphological and Behavioural Differentiation in a Pipefish

    Författare :Sarah Robinson-Wolrath; Anders Berglund; Mats Björklund; Felicity Huntingford; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; population differentiation; phenotypic plasticity; mate choice; pipefish; video playback; Biologi; Biology; Biologi;

    Sammanfattning : A central goal of evolutionary biology is to understand the processes responsible for morphological, genetic and behavioural differentiation between sexes and among geographically distinct populations. Perhaps the most significant processes are genetic drift, natural selection, phenotypic plasticity and sexual selection. LÄS MER