Fig. 2

Percentage of functional sites in discrete Fst bins. Polymorphic sites and substitutions were ordered into bins based on their Fst score. For each bin sites were categorized according to their putative function. The number of sites in each functional category are plotted as a percentage of the total sites in that bin. Values at top refer to total number of sites in each bin. Synonymous sites, which are assumed to be selectively neutral, decline as a percentage of total sites as the Fst score of the bin increases. In contrast, we observe an increase in the percentage of several categories functional sites in the top bins [0.95–1, 1]. This may be the result of positive selection raising these variants to high frequency and fixation