title: Evolution retraces its steps to advance.
abstract: Bacteria in a long-term evolution experiment evolved a new metabolic trait via two separate mutations with opposite effects.
authors.affiliation: Department of Plant Sciences, University of California, Davis, Davis, United States.
authors.forename: Daniel J
authors.identifier: http://orcid.org/0000-0001-5759-3175
authors.initials: DJ
authors.lastname: Kliebenstein
mesh_terms: D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D019143:Evolution, Molecular; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D009154:Mutation
keywords: E. coli; epistasis; evolutionary biology; evolutionary innovation; experimental evolution; flux balance analysis; genomics; metabolic network