Fig. 1
Construction of ancestral SWS1 pigments from 33 present-day sequences. (a) A composite phylogenetic tree with the λmaxs at 10 critical nodes. The numbers beside various branches indicate the numbers of mutations introduced into present-day and ancestral pigments. Arrows indicate the direction of the reconstruction of ancestral pigments. The numbers after each organism (and their SWS1 pigments) indicate their λmaxs. UV- and violet-sensitive pigments are distinguished by black and blue rectangles, respectively. (b) The neutral and adaptive mutations in ancestral pigments (black and blue circles, respectively). (c) Statistically inferred ancestral amino acids that have PP < 95 % (in black circles). The 2-D models are after Palczewski [97]