Fitness graphs for E. coli in three different environments

Fitness graphs are plots of fitness as a function of genotype. Genotypes are placed by the number of mutations they are away from an arbitrary wild-type. Genotypes are connected to neighbors that differ by a single mutation.

Data is from 

Flynn, K. M., Cooper, T. F., Moore, F. B.-G., & Cooper, V. S. (2013). The Environment Affects Epistatic Interactions to Alter the Topology of an Empirical Fitness Landscape. PLoS Genetics, 9(4), e1003426. doi:10.1371/journal.pgen.1003426