Plot of initial pairwise (A) and lineage-based (B) ω values for putative genes in HmYb. Pairwise ω values for HmYb, the locus controlling the yellow hindwing bar, are plotted across the genomic region for H. m. melpomene cythera and H. m. malleti calculated using available 454 contigs, and the three focal Heliconius species, H. erato, H. numata, and H. melpomene using BAC sequences (A). The solid lines connecting data points indicate genes found on the forward strand, while the dotted lines indicate genes located on the reverse strand. Gaps in data reflect inadequate 454 contig coverage across races and species. Lineage-based analyses were used to estimate background ω values by averaging ratios over all sites and across all branches of the three focal polymorphic species, as illustrated in the inset tree topology (model = 0; NSsites = 0 in CODEML) (B). All plotted data are tabulated (Table 1).