Representative Bp Genes Exhibiting Signatures of Positive Selection.

P values are derived from likelihood ratio tests (Model M2a vs M1a, or M8 with M7). Ka/Ks - Ratio of nonsynonymous (Ka) to synonomous (Ks) mutation rates. Ka/Ks values of >1 indicate positive selection, with larger values indicating stronger selection. COG pathway codes are as follows: G, carbohydrate transport and metabolism; I, Lipid transport and metabolism; K, transcription; M, cell wall/membrane biogenesis; N, cell motility; Q, secondary metabolites biosynthesis, transport and catabolism; and T, signal transduction mechanisms; “-” indicates that no COG category was assigned.