Figure 1 .
(A) Frequency distribution of the interspecific differentiation index (D) for each of the 9731 predicted SNPs in G. firmus and G. pennsylvanicus. For any given SNP, D represents allele frequency differences between the two species (see Materials and Methods). (B) Frequency distribution of the number of highly differentiated SNPs (D ≥ 0.98) per contig.