Sperm Selection by FemalesThe history of sexual-selection studies reveals an increasing recognition of the active role of females in determining microevolutionary trajectories. Early studies emphasized male tactics such as combat and scramble competition, and doubted the evolutionary significance of female choice. Even after female choice was convincingly documented, its role was believed to be restricted to pre-copulatory phenomena.1-3 Despite an increased recent focus on sperm competition within a female's reproductive tract, the female has typically been viewed as providing the arena of competition, rather than being an active participant in the selective process.4 Our studies of lizards provide the first clear evidence of active selection of sperm by females, in ways that enhance female fitness.
In the Swedish sand lizards (Lacerta agilis) we have studied, . . .
--M. Olsson et al., "Sperm Selection by Females," Nature