Figure 1.

Illustrative example of an ARG. RE indicates recombination events. Numbers in nodes indicate intervals of ancestral material. Note that each recombinant fragment (1–2, 3–6, and 7–9) has its own most recent common ancestor (MRCA), all of which finally coalesce into a grand MRCA (GMRCA). At the bottom, the trees corresponding to each recombinant fragment are shown.