FIG. 5.—

Distribution of rapidly evolving codons in the songbird TAS2Rs. The protein domains of all the white-throated sparrow TAS2Rs were predicted using TMHMMv2.0 (Krogh et al. 2001), and the location of the domains in representative TAS2R, TAS2R1 is illustrated here (e = extracellular, m = transmembrane, and i = intracellular). Amino acids corresponding to codons associated with an ω > 1 with a Bayesian posterior probability >0.95 in all models (M3, M2a, and M8) are indicated by ^. Amino acids corresponding to codons that were excluded from the estimates of ω are marked by an x.