Figure 2.

Experimental evolution of Escherichia coli under two population dynamics. We evolved two independent clonal lines (A and B) and five population lines (P1–P5) derived from a single ancestral population of a hypermutagenic strain of E. coli lacking the repair gene mutS under strong population bottlenecks and rich growth medium. Evolution proceeded with daily passaging a single colony to a new plate for 250 days in line A and 260 days in line B or by daily passaging 1% (100 μl) of populations P1–P5 to fresh LB broth (10 ml). Genomes were sequenced at the end of the evolution experiment.