Results of test of positive selection.

Selective pressures are divided into three classes: ω0 (dN/dS<1, negative selection), ω1 (dN/dS = 1, neutral evolution) and ω2 (dN/dS ≥1, positive selection). p0, p1 and p2a+p2b are their respective proportion. lnL0 and lnL1 are the likelihood values of the null (ω2 = 1) and alternative (ω2≥1) models, respectively. The likelihood ratio test [2*(lnL1-lnL0)] allows discriminating between neutral evolution and positive selection. A p-value<0.01 presents a significant test (marked as **). Sites under positive selection with BEB score >95% are shown.