TABLE 1.

Commonly used notation

Symbol	Usage
N	Total population size
μ−	Wild-type mutation rate per genome
μ+	Mutator mutation rate per genome
U	Mutation rate into mutator state
L	Length of genome
b	Number of 1's in genome
δ	Fraction of mutations that are lethal
x	Mutator frequency
	Average mutation rate per genome
R ≡ μ+/μ−	Mutator strength
r ≡ b/L	Growth rate per individual per simulation time step
s = 1/b	Selection coefficient of nonlethal mutation
α ≡ 1 − b/L	Fraction of 0's in the genome
αe ≡ α(1 − δ)	Fraction of mutations that are beneficial