Phylogenetic relationships among the organisms used in this study. Three phylogenetic trees were constructed, each of which used a different distance metric. Panel (A) depicts the tree constructed using the 16S rRNA gene similarity between two isolates, while panels (B) and (C) depict trees based on shared proteins and average unique proteins, respectively. Due to space constraints, collapsed trees are shown; the full trees are available as additional files 2, 3, and 4. The length of the base of each triangle represents the number of species within the genus, while the height indicates the amount of intra-genus divergence.