Table 1.

Amino Acid and Nucleotide Substitutions for Visual Opsin Classes.

	n	Amino Acids	Nucleotides
		Divergence Mean±SE	dN Mean±SE	dS Mean±SE
Within class
Rh1	36	0.179±0.006	0.126±0.006	0.994±0.059
Rh2	21	0.194±0.009	0.145±0.009	1.071±0.057
SWS2	15	0.282±0.016	0.230±0.016	1.093±0.032
SWS1	15	0.274±0.025	0.230±0.023	1.140±0.066
LWS	28	0.184±0.007	0.142±0.007	1.104±0.054
Between class
Rh1/Rh2	63	0.266±0.003	0.204±0.003	1.093±0.032
Rh1/SWS2	54	0.485±0.004	0.460±0.005	1.053±0.038
Rh1/SWS1	54	0.530±0.003	0.532±0.006	1.065±0.037
Rh1/LWS	72	0.608±0.002	0.665±0.003	1.019±0.037
Rh2/SWS2	42	0.475±0.004	0.461±0.005	1.097±0.042
Rh2/SWS1	42	0.524±0.003	0.532±0.006	1.192±0.044
Rh2/LWS	56	0.594±0.002	0.669±0.004	1.114±0.042
SWS2/SWS1	36	0.505±0.005	0.511±0.008	1.038±0.042
SWS2/LWS	48	0.605±0.002	0.681±0.004	1.021±0.047
SWS1/LWS	48	0.570±0.002	0.622±0.004	1.056±0.045

Note.—The sequences used are those shown in fig. 2, after omission of the partial Mordacia mordax Rh1. Amino acid divergence is the proportion of substitutions per site, with no correction for multiple substitutions. Nonsynonymous (d_N) and synonymous (d_S) substitutions were estimated by the modified Nei–Gojobori method (Nei and Gojobori 1986; Zhang et al. 1998) with correction for multiple substitutions, as implemented in Mega6. The values shown are the mean and standard error for comparisons within and between classes, and n is the number of pairwise sequence comparisons.