TABLE 4.

Molecular clock results

Model	Data	pa	Log Lc	Evolutionary rate (nucleotide substitutions/site/yr)
Different rates	pol	30	−2,148.63	NAb
	env gp41	28	−2,294.18
Single rate	pol	19	−2,186.81	NA
	env gp41	18	−2,320.77
Single rate dated tips	pol	20	−2,172.89	1.21E-03
	env gp41	19	−2,308.45	2.11E-03
Local clock dated tips	pol	21	−2,162.15	Background, 0.973E-03 Foreground, 6.16E-03
	env gp41	20	−2,308.36	Background, 2.06E-03
				Foreground, 2.45E-03

^ap denotes the number of parameters used in the model.

^bNA, not applicable.

^cLog L, log likelihood.