LAUSR

Ecological interactions emerge spontaneously in an experimental study of bacterial populations cultured for 60,000 generations, and sustain rapid evolution by natural selection. See Letter p.45 The Escherichia coli long-term evolution experiment (LTEE) is the longest running bacterial evolution experiment, including 12 replicate populations of E. coli serially propagated for more than 60,000 generations. Michael Desai, Richard Lenski and colleagues now report whole-genome sequencing at 500-generation intervals over the course of the 60,000 generations from the LTEE. Their analyses reveal a complex and dynamic evolutionary process of long-term bacterial adaptation in this controlled environment, and include findings on clonal inference, genetic drift and shifting targets of selection.