Figure 3From: Dating the time of viral subtype divergenceHistograms of the time of most recent common ancestor for subtypes A-H3N2, B and C, respectively, derived from molecular clock estimates on hemagglutinin (HA), matrix (MP) and nonstructural (NS) gene sequences. (a) Subtype A-H3N2 (b) Subtype B (c) Subtype C.Back to article page