Figure 2.

Phylogenetic relationships of different primate species showing the different residues found at site 86 in SWS1 opsins, together with the corresponding codon sequences. The effects on nucleotide substitution of the alternative hypotheses of ancestral (1) Phe86 or (2) Tyr86 are shown. Lower case is used to indicate substitutions in codon 86. Solid lines are lineages with functional SWS1 pigments, dashed lines and italics indicate species where SWS1 pseudogenes are present. The tree was modified from Perelman et al. [36]. Branch lengths do not reflect evolutionary distances.