Figure 2 From: Evolution and diversity of Rickettsiabacteria Relationships and approximate dates of divergence of the major clades within the order Rickettsiales. The 16S rDNA phylogeny was reconstructed using one member of each of the groups shown with a molecular clock enforced (enforcing the clock did not reduce the likelihood of the tree: likelihood ratio test lnL = 13.84, df = 12 p = 0.311).Back to article page