Table 2.

A summary of the determinants of the evolutionary outcome of sexual conflict in relation to the subject of conflict. (‘—’indicates no clear prediction.)

	PI per offspring	fecundity	mating probability	remating interval
benefit of manipulation to male	small (and non-existent under the assumptions of Smith & Fretwell's (1974) model)	may be large	may be large	may be large
fitness obtained by male at female's optimal value of conflict trait	large (also as a proportion of fitness obtained by the male at his optimum)	some	none	—
as value of conflict trait moves from female's to male's optimum:
selection gradient on manipulation by male	decreases	is constant	is constant	probably decreases
selection gradient on resistance by female	increases	increases	is constant	—
benefit of resistance to female	large	large	may be small	may be small
costs of manipulation	opportunity costs	—	no opportunity costs	—
strategy set for manipulation:
exploitation of internal signalling system	difficult	possible	possible	possible
exploitation of external signalling system	difficult	difficult	possible	—