Author(s): Roesti, M, Gavrilets S, Hendry AP, Salzburger W, Berner D
Understanding how natural selection shapes the genome is becoming a major endeavor in evolutionary biology. Selection will often target pre-existing (standing) genetic variation. Nevertheless, theory has generally been developed for selection on novel variants. We here use extensive modeling tailored to adaptive divergence in threespine stickleback to characterize the genomic footprints of adaption from shared standing variation. The emerging predictions are then examined using genome-wide markers and targeted sequencing across many natural populations. Combined, our findings offer a novel explanation for heterogeneous genomic differentiation between diverging populations, challenge the widely held view that genomic regions of high and low population differentiation reliably point to loci under divergent and balancing selection, and allow us to propose a novel methodological framework for searching adaptation genes in natural populations.