Figure 2.

Anticipated fates for different mutations in the RdRp gene incurred during viral replication under the BIAS model. The meanings of all symbols are given in the top left box, as well as in cell A. Rectangles with rounded corners represent different cells, with A as the primarily infected cell, B, C1, D1 as representatives of second-round cells, and C2, D2, as cells infected by progenies of C1 and D1, respectively. Note that replication in all cells gives rise to new mutations that are depicted as either red (deleterious) or yellow (beneficial) mutations at different positions of the RdRp ORF.