Abstracts (first author)
Quantifying the neutral expectations of genomic patterns of divergence
With decreasing costs of sequencing, we see a tremendous accumulation of genomic data from natural populations and non-model organisms in particular. However, a rigorous understanding of the processes that determine the evolution of genomic islands of divergence is still incomplete. Moreover, we lack well-defined neutral expectations of genome-wide differentiation, making it hard to distinguish neutral patterns from true signatures of selection. To help theory keep up with the rapid accumulation of data, we use coalescent simulation modeling of neutral divergence with gene flow to fully characterize genome-wide distributions of Fst. Mean, variance and skew of Fst across the genome depend strongly on migration and mutation rates. In addition, autocorrelation in divergence along the genome resulting from physical linkage can lead to neutral patterns that strongly resemble genomic islands. These findings challenge our interpretations of genomic variation in the context of ecological divergence. A more comprehensive baseline of neutral expectations will help determine which statistics describing genomic patterns have the most power to distinguish genomic islands of divergence resulting from selection as opposed to neutral processes.