Figure 2
Per-gene differences in (a) dN/dS and (b) CDC between reproductive modes within each hexapod group. The boxplots show the distribution of per-gene differences in dN/dS between the sexual and asexual terminal branch (Δsex-asex dN/dS) and of per-gene differences in CDC between the sexual and asexual species (Δsex-asex CDC) of each of eight hexapod groups for 99 orthologues. For better representation, the ordinate is restricted to between −0.06 and 0.06 and −0.1 and 0.1, respectively, and outliers outside of 1.5 times the interquartile range (whiskers) are excluded. For dN/dS seven of eight within-hexapod-group comparisons between sexual and asexual branches yielded non-significant results (see Table 1). The red plot denotes a significantly lower per-gene dN/dS in sexual as compared to asexual terminal branches of Zygentoma (V = 3786, P < 0.001***; Wilcoxon signed-rank test). For CDC four of eight within-hexapod-group comparisons between sexual and asexual branches yielded significant results (see Table 1). There was significantly higher per-gene CDC in sexual as compared to asexual Collembola and Phasmatodea (red plots; V = 1191, P < 0.001*** and V = 1832, P = 0.025*, respectively; Wilcoxon signed-rank test) contrasting a significantly lower per-gene CDC in sexual as compared to asexual Zygentoma and Sternorrhyncha species (blue plots; V = 4198, P < 0.001 and V = 3562, P < 0.001, respectively; Wilcoxon signed-rank test).
