Table 2.

Selective pressure analyses of SABATH genes in S. miltiorrhiza by branch-site model.

Foreground Branches	Branch-Site Model	lnL	2ΔlnL	p Value	ω Values 1	Positively Selected Sites 2
Group A	Null	−23,766.855109	0	1	ω0 = 0.23043 ω1 = 1.00000 ω2 = 1.00000	None
	Alternative	−23,766.855151			ω0 = 0.23043 ω1 = 1.00000 ω2 = 3.05353
Group B	Null	−23,766.855088	5.653506	0.017	ω0 = 0.23043 ω1 = 1.00000 ω2 = 1.00000	152 A 0.649 209 A 0.815 385 R 0.516
	Alternative	−23,764.028335			ω0 = 0.23051 ω1 = 1.00000 ω2 = 464.10117
Group C	Null	−23,766.466691	12.07159	<0.01	ω0 = 0.22946 ω1 = 1.00000 ω2 = 1.00000	137 K 0.772 200 I 0.514 252 H 0.889 461 A 0.961 *
	Alternative	−23,760.430894			ω0 = 0.22951 ω1 = 1.00000 ω2 = 998.97795

Note: * p < 0.05 and ** p < 0.01 (x² test). ¹ ω was estimated under model Null and Alternative. ² The number of amino acid sites estimated to have undergone positive selection. lnL was the values of log-likelihood. 2ΔlnL was the value of twice the log likelihood difference between models.