(a–f) Show single-cell swimming phenotypes (run duration (), run speed (), tumble bias and tumble frequency, see Materials and methods). Tracking was performed for founding strain (140 cells, 19,597 run events), strains isolated after 5 (79 cells, 12,217 run events), 10 (97 cells, 18,505 run events) and 15 (96 cells, 15,928 run events) rounds in rich media and in minimal media for the founding strain (72 cells, 7556 run events), round 5 (45 cells, 9724 run events) and round 10 (25 cells, 4892 run events). (a) Shows the fraction of runs longer than a given for strains evolved in rich media (95% confidence intervals from bootstrapping). The mean and standard deviation in run duration for founder is 0.66 0.78 s, for round 5: 0.63 0.61 s, for round 10: 0.58 0.50 s and for round 15: 0.65 0.57 s. Round 5, 10 and 15 strains exhibit shorter average run durations than founder (p<0.05). (b) Shows the same distribution for strains in minimal medium with founder exhibiting average run duration 0.49 0.52 s, round 5: 0.44 0.48 s and round 10: 0.33 0.28 s. Rounds 5 and 10 exhibit shorter average run durations than founder (). (c–d) Show average fraction of time spent tumbling (tumble bias) and tumble frequency (tumbles per second) for rich medium and minimal medium respectively. Note the two vertical axes. In rich medium only the round 15 tumble bias is significantly different from founder (p<0.001), but the tumble frequency is higher than founder for both rounds 10 and 15 (p<0.001). In minimal medium all tumble biases and frequencies are significantly different from founder for all strains (p<0.001). (e) Shows run speed distributions for strains evolved in rich medium, legend in (a) applies. The average standard deviation run speeds are, for founder: 18.7 7.1 μm s−1, round 5: 24.9 7.1 μm s−1, round 10: 27.6 7.0 μm s−1, and for round 15: 28.7 6.8 μm s−1. Average run speeds for rounds 5, 10 and 15 are greater than founder (f) Shows the same distributions for strains evolved in minimal medium, average run speed for founder: 20.7 10.8 μm s−1, for round 5: 11.2 4.8 μm s−1 and for round 10: 13.3 4.4 μm s−1. Both rounds 5 and 10 exhibit slower average run speeds than founder, the legend in (b) applies. (g–h) Show growth rates in well mixed liquid culture for all strains studied in panels (a–f) in the medium in which the strains were selected. (g) Shows triplicate measurements from each of the four strains isolated in rich medium. Rounds 5, 10 and 15 exhibit slower growth than founder (p<0.01). (h) Shows growth rates for strains isolated from minimal medium selection experiment. Four replicate measurements were made for founder and round 10 and three replicate measurements for round 5. Squares and circles demarcate measurements made on separate days. Rounds 5 and 10 have higher growth rates than founder (p<10-5).