Fig. 2.

Breakdown of the trade-off between transfer and host fitness under antibiotic selection. Host growth in the absence of antibiotics (A, donor cell density during conjugation assays) and in the presence of high levels of antibiotics (B, density of cells able to grow on Amp 0.5 g/L) is shown for midpoint coevolved clones as a function of their transfer rate. Dots and lines indicate, respectively, the geometric average and SE (n = 3).