Il giorno 30 gennaio 2026 presso il DiSIA, in sala riunioni 205, alle 11.00, Peter McCullagh (John D. MacArthur Distinguished Service Professor Department of Statistics and the College, Department of Statistics University of Chicago) terrà un seminario dal titolo: “Statistics of speciation and the evolution of reproductive isolation”
Abstract
This talk is concerned with statistical models for the analysis of an experiment in evolutionary biology. The experiment described by Villa et al. (PNAS 2019) is concerned with adaptive evolution of an organism in response to selective pressure. The catchy title "Rapid experimental evolution of reproductive isolation from a single natural population” implies that evolution is observed on short time scales on the order of 50 generations. I will describe the experimental design, the host-parasite system, the randomization scheme and the sampling protocol. One flaw of the statistical model leading to the advertised conclusion is that it contradicts the randomization scheme. An alternative model (due to Cavalli-Sforza & Edwards (1967)) using Brownian motion for the temporal evolution of a quantitative trait is shown to conform to the randomization scheme. It is also a substantially better fit to the data. Unfortunately, the alternative analysis shows that, while adaptive evolution is indeed possible, the authors' data provides zero evidence in support of that conclusion.