title: Hidden randomness between fitness landscapes limits reverse evolution.
abstract: In biological evolution, adaptations to one environment can in some cases reverse adaptations to another environment. To study this "reverse evolution" on a genotypic level, we measured the fitness of E. coli strains with each possible combination of five mutations in an antibiotic-resistance gene in two distinct antibiotic environments. While adaptations to one environment generally lower fitness in the other, we find that reverse evolution is rarely possible and falls as the complexity of adaptations increases, suggesting a probabilistic, molecular form of Dollo's law.
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. tantan@mit.edu
authors.forename: Longzhi
authors.initials: L
authors.lastname: Tan
authors.forename: Stephen
authors.initials: S
authors.lastname: Serene
authors.forename: Hui Xiao
authors.initials: HX
authors.lastname: Chao
authors.forename: Jeff
authors.initials: J
authors.lastname: Gore
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D005075:Biological Evolution; D004351:Drug Resistance / Q000235:genetics*; D004777:Environment; D004843:Epistasis, Genetic; D004926:Escherichia coli / Q000235:genetics*; D005799:Genes, Dominant; D056084:Genetic Fitness / Q000235:genetics*; D005838:Genotype; D008957:Models, Genetic; D009154:Mutation; D012641:Selection, Genetic
chemical_list: D000900:Anti-Bacterial Agents