a Lineages defined as foreground in the branch-site analysis (Figure 5). b The number in parenthesis indicates the P-values under the one-sided test with the asymptotic null distribution (a 50:50 mixture of point mass 0 and χ2) in . c Amino acid position numbering according to the MSA in Figure 2. Amino acid positions involving changes in the physicochemical properties influenced by positive selection are highlighted in bold. BEB, Bayes Empirical Bayes results .