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Research article2013Peer reviewed

Is local selection so widespread in river organisms? Fractal geometry of river networks leads to high bias in outlier detection

Fourcade, Yoan; Chaput-Bardy, Audrey; Secondi, Jean; Fleurant, Cyril; Lemaire, Christophe

Abstract

Identifying local adaptation is crucial in conservation biology to define ecotypes and establish management guidelines. Local adaptation is often inferred from the detection of loci showing a high differentiation between populations, the so-called FST outliers. Methods of detection of loci under selection are reputed to be robust in most spatial population models. However, using simulations we showed that FST outlier tests provided a high rate of false-positives (up to 60%) in fractal environments such as river networks. Surprisingly, the number of sampled demes was correlated with parameters of population genetic structure, such as the variance of FSTs, and hence strongly influenced the rate of outliers. This unappreciated property of river networks therefore needs to be accounted for in genetic studies on adaptation and conservation of river organisms.

Keywords

FST outliers; fractal landscapes; genome scan; hydrographic network; migration model

Published in

Molecular Ecology
2013, Volume: 22, number: 8, pages: 2065-2073 Publisher: WILEY-BLACKWELL

    UKÄ Subject classification

    Ecology

    Publication identifier

    DOI: https://doi.org/10.1111/mec.12158

    Permanent link to this page (URI)

    https://res.slu.se/id/publ/85328