Sökning: "diversification rates"

Visar resultat 1 - 5 av 25 avhandlingar innehållade orden diversification rates.

  1. 1. Bayesian Phylogenetic Inference : Estimating Diversification Rates from Reconstructed Phylogenies

    Författare :Sebastian Höhna; Tom Britton; Fredrik Ronquist; Ziheng Yang; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Phylogenetics; Bayesian inference; Graphical Models; Birth-Death Process; Diversification; matematisk statistik; Mathematical Statistics;

    Sammanfattning : Phylogenetics is the study of the evolutionary relationship between species. Inference of phylogeny relies heavily on statistical models that have been extended and refined tremendously over the past years into very complex hierarchical models. LÄS MER

  3. 2. Multi-trait Branching Models with Applications to Species Evolution

    Författare :Daniah Tahir; Ingemar Kaj; Martin Lascoux; Asger Hobolth; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Markov models; branching processes; density dependence; discrete traits; species trees; diversification rates; diffusion approximation;

    Sammanfattning : This thesis provides an analysis of the evolution of discrete traits and their effect on the birth and survival of species using the theory of supercritical, continuous time Markov branching processes. We present a branching modeling framework that incorporates multi-trait diversification processes associated with the emergence of new species, death of existing species, and transition of species carrying one type of a trait to another. LÄS MER

  4. 3. Microbial evolution: patterns of diversity in aquatic protists

    Författare :Ramiro Logares; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; dinoflagellates; biodiversity; lakes; Evolution; diversification; microbes; biogeography;

    Sammanfattning : Little is known about how microbes diversify in nature. In contrast to the more studied multicellular organisms, microbes can have a) huge population sizes, b) high reproductive rates and c) long-distance dispersal. These characteristics can affect their tempo and mode of diversification in ways that still need to be understood. LÄS MER

  5. 4. Essays on exchange rates and international finance

    Författare :Marianne Nessén; Handelshögskolan i Stockholm; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES;

    Sammanfattning : This dissertation consists of three essays. Essay 1: Common Trends in Prices and Exchange Rates – Tests of Long-Run Purchasing Power Parity. This essay examines the empirical validity of long-run purchasing power parity by means of multivariate cointegration tests due to Johansen (1988, 1991a). LÄS MER

  7. 5. Rural Income Diversification, Employment, and Differentiation in Kenya and Implications for Rural Change

    Författare :Maria Fibaek; Ekonomisk utveckling i det globala Syd; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Rural Development; Income Diversification; Differentiation; Agrarian Political Economy; Kenya;

    Sammanfattning : To contribute to contemporary rural development debates, the present thesis conducts a contextual analysis of rural development using Kenya as a case study from the colonial era to today. To perform the analysis, two critical trends in rural Africa are focused on: socioeconomic differentiation and rural income diversification, with a particular focus on large-scale farm employment. LÄS MER