Figure 2.

Linear regression plots of root-to-tip divergence over time of major sub-lineages of HCoV-HKU1. Circles at nodes in the ML phylogeny relying on complete spike genes indicate support of ≥80 SH-alrt/≥95 UFBoot for major clades. Scale bars indicate number of nucleotide substitutions per site. Linear regression of root-to-tip genetic distances over time in years after exclusion of recombinant sequences (detailed in Table S1). The date range, slope (rate), correlation coefficient (r), and R² are shown in the graph.