Fig. 4: Mobility-induced competition drives lineage spread.

Phylogeny represents the 2019/2020 B/Victoria season, with the six largest lineages labeled in order of size. Top row of maps represents the reconstructed spread and distribution of each of the six largest lineages. Bottom row of maps represents the simulated spread and distribution of the six lineages, initialized in the lineages’ likely onset state and onset week, using a combination of air travel data and commuting data. Circle sizes are scaled as in Fig. 3.