Figure 8.

Within-host competitive fitness of all trajectories explored. For all the trajectories proposed (x-axis), the fitness (W at the y-axis) was plotted. The viruses with the NIb gene moved to intergenic positions 3–8 and 10 are nonviable genotypes (upper panel; W < 0). The trajectories of viruses with NIb moved to intergenic positions 1 and 2 are indicated in the middle and lower panels, respectively. Red lines indicate a decrease in fitness, black lines indicate no significant change in fitness, and green lines indicate an increase in fitness. Note how the ancestral and evolved TEV-NIb₁-ΔNIb₉ and TEV-NIb₂-ΔNIb₉ lineages have an inferior within-host competitive fitness compared to their ancestral TEV-NIb₁-NIb₉ and TEV-NIb₂-NIb₉ viruses (respectively) and the wild-type TEV.