Adaptive Evolution of the Lactose Utilization Network in Experimentally Evolved Populations of Escherichia coli
A) Fitness of lacI and lacO1 mutants in the four evolution environments. Competitions were performed for lacI versus the ancestor, lacO1 versus the ancestor and lacI versus lacO1. As a control, we included the ancestor competed against itself. The red dotted line indicates a relative fitness of 1 (no fitness difference). 95% confidence intervals are shown for each competition (n≥8).