Figure 2

Maximum clade credibility phylogeny and timing for the NA gene. Phylogeny was estimated using the models reported in Figure 1. H1N2 strains are colored according to the phylogenetic classification of the HA gene. The most interesting internal nodes, which reconstructed common ancestors with 95% credibility intervals, are reported. Numbers 1, 4 and 5 refer to the reassortment events described in Figure 3. For each node posterior probability is reported.