Figure 9. Washington tip branch lengths in days.

For each Washington tip in the full North American phylogeny with an estimated branch length in time units of ≤1 year, we show the estimated branch length in days with the 95% confidence interval. The solid line at 18 represents the mump serial interval. For most tips, the estimated branch length is variable, depending on the placement of its parental internal node. This variability in internal node placement complicates setting a clear threshold for branch lengths based on time.