Table 2.

Parameter estimates and log likelihood values under different branch models for the snakes’ opsin genes

					ω values
	Model	ℓ	p	BIC	Non-snakes	Henophidian Snakes	Colubridae Snakes
							Colubrinae	Dipsadinae
LWS	1ω	−11,887.4	149	24,154.6	0.151	0.151	0.151	0.151
	2ω	−11,778.4	150	23,939.1	0.094	0.414	0.414	0.414
	3ω	−11,765.1	151	23,915.0	0.094	0.149	0.498	0.498
	4ω	−11,761.3	152	23,910.0	0.094	0.171	0.659	0.395
							Diurnal	Nocturnal
	4ω (D x N)*	−11,764.5	152	23,916.4	0.094	0.148	0.549	0.450
	FM	−11,567.6	295	23,887.3	–	–	–	–
RH1	1ω	−11,225.5	145	22,820.7	0.107	0. 107	0. 107	0. 107
	2ω	−11,165.1	146	22,702.3	0.071	0.231	0. 231	0. 231
	3ω	−11,162.1	147	22,698.9	0.071	0.137	0.250	0. 250
	4ω	−11,161.0	148	22,699.3	0.071	0.157	0.213	0.299
							Diurnal	Nocturnal
	4ω (D x N)*	−11,150.9	148	22,679.0	0.071	0.154	0.161	0.391
	FM	−11,012.3	287	22,756.1	–	–	–	–
SWS1	1ω	−14,413.9	153	29,217.9	0.065	0.065	0.065	0.065
	2ω	−14,394.6	154	29,181.8	0.051	0.093	0.093	0.093
	3ω	−14,388.9	155	29,172.8	0.051	0.047	0.102	0.102
	4ω	−14,385.6	156	29,168.8	0.051	0.046	0.122	0.082
							Diurnal	Nocturnal
	4ω (D x N)*	−14,384.7	156	29,167.0	0.051	0.047	0.128	0.081
	FM	−14,165.7	303	29,103.7	–	–	–	–

^*D x N, primarily diurnal and primarily nocturnal lineages, with independent ω values

FM free model, l likelihood value