Table 2.

Comparison of candidate positively selected genes (PSGs) and those not exhibiting positive selection (non-PSGs)

Category	No. of genes	No. of base pairs	Mean No. of codons	Mean p1 M8a	Mean LRT Scoreb	Mean dN	Mean dS	Mean dN/dSC
PSGs	1008	2,188,170	502.4	0.0399	13.67	0.0844	0.333	0.253
Non-PSGs	5512	8,487,210	341.8	0.0544	1.35	0.0503	0.340	0.148
TOTAL	6520	10,675,380	366.6	0.0521	3.26	0.0556	0.339	0.164

^aMean percentage of codons with d _N /d _S ratios >1 identified by PAML model M8

^bMean Likelihood Ratio Test Score comparing PAML models M7 and M8

^cCalculated following Wolf et al. (2009)