TABLE 1.

Parameter definitions

Parameter	Definition
Lock	Identity of the mod function
Key	Identity of the resc function
S	Length of the lock and key sequences
n	No. of possible states at each site of the lock   and key sequences
MI and MImaxa	Mod intensity: embryonic mortality in   unidirectional CI
TE and TEmaxa	Transmission efficiency
FE and FEmaxa	Fitness effect: fecundity of infected females   relative to uninfected
Mu	Mutation rate
Ne	Female host population size

^aUpper limits can be set to values <1 for MI, TE, and FE. The upper limits for these parameters are denoted MI_max, TE_max, and FE_max, respectively.