Figure 2. Root-to-tip distance in a neighbour joining tree for segment 1 (encoding PB2) of the influenza C genome.

100 full-length or near full-length genome segments (2365 bases) are used plus the 724 discontinuous bases of segment 1 derived from deep sequencing. C/Lancaster/1/2015 has a degree of divergence from the root consistent with molecular clock-like behaviour in its lineage.