Relative node depths of incongruences between host and virus phylogenies showing the median and 25^th and 75^th percentiles (boxplots) as well as the raw data.

<p>A relative node depth close to 0 can be interpreted as the occurrence of host-switching events at the tips of the phylogenetic tree, whereas a relative node depth close to 1 suggests host-switching events at the root of the phylogenetic tree. A range of DNA (blue) and RNA (yellow) virus families are shown. For ease of interpretation virus families are ranked as in <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1006215#ppat.1006215.g002" target="_blank">Fig 2</a>.