The Evolutionary Relationship between Microbial Rhodopsins and Metazoan Rhodopsins

Figure 3

Unrooted Bayesian tree for all microbial rhodopsin genes. The numbers adjacent to the nodes are posterior probability values. The length of branch reflects evolutionary divergence. Microbial rhodopsin genes distantly related to metazoan rhodopsin’s ancestral states (>95% quantile) are marked with a filled black triangle ▲. The tree node where microbial rhodopsin’s ancestral state is built on is marked with a filled black square ■. In all possible ancestral states on that branch (marked with vertical line), this microbial rhodopsin’s ancestral state has the smallest mutation distance with metazoan rhodopsin’s ancestral states.