Fig. 2.

Example of an ARG for the England (January) data set. Recombination nodes are shown in blue, labeled with the recombination breakpoint, with the offspring sequence inheriting part of the genome to the left (right) of the breakpoint from the parent labeled “P” (“S”). Recurrent mutations are prefixed with an asterisk. Edge carrying the characteristic mutations of lineage B.1.1.7 is highlighted in red; nodes corresponding to sequences from lineage B.1.1.7 are colored purple. For ease of viewing, some parts of the ARG have been collapsed into nodes labeled “E….” Edges are labeled by positions of mutations (some mutated sites are not explicitly labeled and are denoted by a dot instead).