Table 1 Potential forms of selection on mutation rate modifiers discussed in this review

From: Experimental evolution and the dynamics of genomic mutation rate modifiers

Source of selection

Type of selection

Strength

Outcome

Hitchhiking with beneficial mutations

Indirect

Strong, immediate

Favors higher rate

Increased load of deleterious mutations

Indirect

Weak, delayed

Favors lower rate

Cost of genomic replication fidelity

Direct

Weak

Favors higher rate

Pleiotropic fitness effects of modifiers

Direct

Largely unknown

Unknown