Log-likelihood values and parameter estimates under random-site models for P. toxostoma and C. nasus.

The number following the model code given in parentheses represents the number of free parameters for the ω ratios. Parameters in parentheses are presented for clarity only but are not free parameters; for example, under M8 p1 = 1-p0; PSS are the positive selected sites identified using the BEB method at.*: P>95%;**: P>99%;ω is the selection parameter; pn is the proportion of sites that fall into the ωn site class; p and q are the shape parameters of the β function (for M7 and M8 models).