Figure 8.

Sexual conflict resolution in the sperm selection model of Ball & Parker (2003), where male roles are random (see text). (a) Female's sperm selection strategy, measured as the proportion, r, of sperm from the disfavoured male that are left in her tract. Most intense sperm selection occurs at intermediate viabilities of offspring from the disfavoured male (at the minimum of the r curve). (b) Male's ejaculation strategy: upper curve is the number of sperm ejaculated in the favoured role, lower curve is sperm number in the disfavoured role. Modified from Ball & Parker (2003).