Sökning: "Punctuated equilibrium"

Hittade 5 avhandlingar innehållade orden Punctuated equilibrium.

  1. 1. The tempo and mode of evolution : a neontological reappraisal

    Författare :Melanie Monroe; Folmer Bokma; Pär Ingvarsson; Mikael Fortelius; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; birds; extinction; macroevolution; mammals; microevolution; punctuated equilibrium; speciation;

    Sammanfattning : The theory of “punctuated equilibrium” suggests that species evolve rapidly during or immediately upon speciation, “punctuating” long periods of little or no morphological evolution. Here I confirm that body size differences within clades of birds and mammals are best explained using a model of punctuated evolution. LÄS MER

  3. 2. Stochastic Models in Phylogenetic Comparative Methods: Analytical Properties and Parameter Estimation

    Författare :Krzysztof Bartoszek; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Adaptation; Adaptation; Birth-death process; Branching diffusion; Brownian motions; Conditioned branching process; Evolution; General Linear Model; Hybridization; Macroevolution; Measurement error; Multivariate phylogenetic comparative method; Optimality; Ornstein-Uhlenbeck process; Phyletic gradualism; Phylogenetic inertia; Phylogenetic uncertainty; Punctuated equilibrium; Yule tree; Macroevolution;

    Sammanfattning : Phylogenetic comparative methods are well established tools for using inter-species variation to analyse phenotypic evolution and adaptation. They are generally hampered, however, by predominantly univariate approaches and failure to include uncertainty and measurement error in the phylogeny as well as the measured traits. LÄS MER

  4. 3. Fängslande idéer : Svensk miljöpolitik och teorier om policyproduktion

    Författare :Marianne Danielsson; Li Bennich-Björkman; Barry Holmström; Kristina Boréus; Uppsala universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; policy ideas; theories of the policy process; constructivism; Discourse Coalition Framework; Advocacy Coalition Framework; Punctuated Equilibrium Theory; environmental policy; Sweden; Political science; Statsvetenskap; Statskunskap; Political Science;

    Sammanfattning : This thesis investigates the role of ideas in policy processes. It does so using three theories as a starting point, selected for being alike yet unique in their description of how ideas may “get stuck” in the organization’s production and reproduction of policy. LÄS MER

  5. 4. Fängslande idéer i politik och teori : En teoretisk granskning

    Författare :Marianne Danielsson; Li Bennich-Björkman; Barry Holmström; Andreas Duit; Uppsala universitet; []
    Nyckelord :Punctuated Equilibrium Theory; Advocacy Coalition Framework; Discourse Coalition Framework; Policy analys; policyteori; idéer; statskunskap; statskunskap;

    Sammanfattning : I den snabbt växande litteraturen om idéer i policyprocessen, som ibland kallats ”the ideational turn” tänker man sig ofta att idéer och språk styr politikens aktörer, snarare än styrs av dem. Hur politiska problem formuleras styr vilka lösningar som ter sig rimliga. Intresset riktas mot politik som intellektuell verksamhet. LÄS MER

  7. 5. Ungdomsarbetslösheten - om övergångsregimer, institutionell förändring och socialt kapital

    Författare :Peter Håkansson; Ekonomisk-historiska institutionen; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Ungdomsarbetslöshet; övergångsregim; socialt kapital; utbildning; riskpremie; risk; arbetslöshet; heltidsarbete; deltidsarbete; blind alley-jobs;

    Sammanfattning : Youth unemployment in Sweden has reached record levels during the first decade of the 21st century. In 1970, the unemployment rate for 20-24 year olds was approximately 2%. Now, forty years later, this rate has risen to 20%. Relative youth unemployment (youth unemployment in relation to unemployment for the 25-64 year olds) has also risen. LÄS MER