highly significantp < 0.001
The regression between the selection coefficients of genes (mean of 32 replicates) in CFP strain and YFP strain was highly significant ( F 1,6 = 117, p < 0.001, R 2 = 0.943, slope = 1.007), indicating different fluorescent backgrounds do not interact with this subset of genes, and all measured effects are solely due to the introduced genes.