Summary of sites tests for positive selection.

N, number of species analysed; M1 vs. M2, likelihood ratio test statistic for model M1 versus M2; M7 vs. M8, likelihood ratio test statistic for model M7 versus M8; Parameter estimates: percentage of sites in dN/dS>1 category and estimated dN/dS parameter under model M8. ISG, invariant surface glycoprotein. RHS retrotransposon hot spot protein. * Significance with P<0.05; ** Significance with P<0.01; *** Significance with P<0.001. A CPG jaccard cluster number from El Sayed et al [8].