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Title: Distribution of fitness effects of beneficial mutations
Plain: Extreme-value statistics, the mathematics of the largest values in a random sample, predicts that rare improving mutations in a well-adapted organism follow a simple exponential law. Experiments give mixed support, and which statistical class real mutations follow is unsettled.
Precise: If the wild type is near the top of the fitness distribution of its mutational neighbors, extreme-value theory predicts exponentially distributed beneficial selection coefficients s (Gumbel domain), with Weibull (bounded) or Frechet (heavy-tailed) alternatives. Determine the domain of attraction from large mutant libraries (deep mutational scanning, barcoded lineage tracking) across organisms and environments, and how it depends on distance from the optimum.
Settled by: Large-library measurements of beneficial effects with tail-shape estimation across several organisms and environments.
Kind: well-posed
Answer type: classification
References: (empty)
Literature status: contested
Status note: (empty)
Posed since: (empty)