Results from maximum likelihood codon-based models of selection using Codeml.

P = number of parameters in the ω distribution; K = estimated transition/transversion rate; ω = selection parameter; pn = proportion of sites that fall into the ωn site class; p, q = shape parameters of the β function (for models M7 and M8). Positively selected sites denoted in cursives were significant at P > 95%, while bold sites were significant at P > 99%.Results from maximum likelihood codon-based models of selection using Codeml.