Rapid Evolution of Mycoplasma gallisepticum Figure 4. 95% highest posterior density intervals on the estimated substitution rate. A) for House Finch Mycoplasma strains derived from 34 analyses using the different data and model combinations described in Text S2. The middle circle of each bar is the estimated mean; top and bottom circles are the upper and lower 95% bounds of each highest posterior density (HPDs). b) Root-to-tip graph of sampling date of House Finch Mycoplasma strains versus divergence from the closest sequence in the putative source population TK_2001. A simple regression gives an estimated substitution rate of 1.4561025, consistent with estimates from BEAST. See Text S2 and Text S7 for further information. doi:10.1371/journal.pgen.1002511.g004 PLoS Genetics | www.plosgenetics.org 6 February 2012 | Volume 8 | Issue 2 | e1002511