wijk EJ. Kirin UJ. Wrinreich UM. Tans (2007) Empirical fitness Landscapes reveal accessible evolutionary paths. Nature 445: 383-386. 34 Woods ltj. Barrack JE. Cooper Ti. Shrestha Eatith SIR, et al. (2011) SeceinePorder selection for rwilvability in a large escherichia cnli population. Science 331: 1433