Figure 2. Time calibrated phylogenetic tree of Gammapapillomavirus sequences.

The evolutionary rate estimated for feline PVs²⁶ was used to estimate the divergence time of the indicated nodes. Classification was based on¹⁸,¹⁹. The asterisk (*) indicates that some members of this clade have not yet been officially recognized as members of the Gammapapilliomavirus genus. Support values and exact estimates (with 95% highest posterior density) for each node are presented in supplementary Table 2. The Gamma-6 species is highlighted in red. The tree and geological column were generated using the APE⁵², phyloch (available from http://www.christophheibl.de/Rpackages.html), and strap⁵³ packages within R. The scale bar indicates millions of years before the present. The Gammapapillomavirus genus tree was rooted on CPV2 (indicated by arrowhead in Fig. 1).