Fitnesses and fitness effects of all genotypes tested.

Fitnesses are given as the average plus or minus the standard error. The column labeled gives the number of replicate assays for each genotype. The fitness effect relative to the wild type is designated by . gives the fitness effect expected on the assumption that the effects of single mutations were additive, gives the effect of adding the first mutation in the genotype name into the background of the second, and gives the effect of adding the second mutation in the genotype name into the background of the first.