Fig. 3.

Maximum likelihood phylogenies and distributions of pairwise genetic similarity shown as a density of Hamming distance for H1 Swine, H5 Avian. Maximum likelihood phylogenies illustrating the phylogenetic relationship between 1 same size random sample and the FRI data for a H1 Swine and b H5 Avian. The type of data on each tree is indicated by the tip colour, red tips show FRI data and blue tips show data from 1 same sized random subset. Clustering of particular clades is indicated on the tree. Trees were mid-point rooted. Distribution of pairwise genetic similarity shown as a density of hamming distance for c H1 Swine, d H5 Avian. Isolate comparisons for each host-subtype combination from the reassorted set are indicated in red, and the median across ten same size random subsets of isolates from GenBank for each host/subtype pair is indicated in black. The grey shaded area represents the 10^th and 90^th percentile across the ten same size random subsets. Labelled phylogenies are provided in Additional File 7