Figure 1

A schematic representation of the ML species tree topology. Branch lengths are not to scale. Numbers above branches are percent bootstrap values, numbers below the branches indicate the percentage of gene trees that supported the branch. Taxonomic groups are labelled and shaded for clarity. The term "clade II" poxviruses is used for simplicity and refers to the group of yatapox, deerpox, capripox and suipox, as per convention [11].