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Evolutionary graph theory: Difference between revisions
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== [[Evolutionary graph theory/Evolutionary suppressors|Evolutionary suppressors]] == | == [[Evolutionary graph theory/Evolutionary suppressors|Evolutionary suppressors]] == | ||
[[Image:Evolutionary suppressor (chain).png|thumb|300px|Evolutionary suppressors are structures that reduce selection and enhance random drift, i.e. the fixation probability of advantageous (deleterious) mutants is decreased (increased) as compared to unstructured populations.]] | [[Image:Evolutionary suppressor (chain).png|thumb|300px|Evolutionary suppressors are structures that reduce selection and enhance random drift, i.e. the fixation probability of advantageous (deleterious) mutants is decreased (increased) as compared to unstructured populations. The simplest example is a linear chain with directed links all pointing in the same direction.]] | ||
The characteristic balance between selection and drift in Moran graphs can tilt to either side for graphs that are not circulations. For example, suppose \(N\) individuals are arranged in a linear chain. Each individual places its offspring into the position immediately to its right. The leftmost individual is never replaced. The mutant can only reach fixation if it arises in the leftmost position, which happens with probability \(1/N\), but then it will eventually reach fixation with certainty. Clearly, for such one-rooted graphs the fixation probability of a single, randomly placed mutant is | The characteristic balance between selection and drift in Moran graphs can tilt to either side for graphs that are not circulations. For example, suppose \(N\) individuals are arranged in a linear chain. Each individual places its offspring into the position immediately to its right. The leftmost individual is never replaced. The mutant can only reach fixation if it arises in the leftmost position, which happens with probability \(1/N\), but then it will eventually reach fixation with certainty. Clearly, for such one-rooted graphs the fixation probability of a single, randomly placed mutant is | ||
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