Hidden randomness between fitness landscapes limits reverse evolution

Phys Rev Lett. 2011 May 13;106(19):198102. doi: 10.1103/PhysRevLett.106.198102. Epub 2011 May 11.


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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological / genetics*
  • Anti-Bacterial Agents / chemistry*
  • Biological Evolution*
  • Drug Resistance / genetics*
  • Environment
  • Epistasis, Genetic
  • Escherichia coli / genetics*
  • Genes, Dominant
  • Genetic Fitness / genetics*
  • Genotype*
  • Models, Genetic
  • Mutation
  • Selection, Genetic


  • Anti-Bacterial Agents