Table 2.

The effect of mating assortment (SCIC) and average polyandry on measures of sexual selection

ParameterITCOVMPβMJones’ index
SCIC−0.560 (0.003)−0.084 (0.001)−0.409 (0.002)−0.111 (0.001)
Average polyandry−0.701 (0.016)0.012 (0.001)0.010 (0.003)−0.108 (0.004)
SCIC*Average polyandry0.071 (0.004)0.072 (0.001)0.032 (0.002)0.055 (0.001)
  • Linear mixed model results for the effects of population-level average polyandry and sperm competition intensity correlation (SCIC) on the opportunity for selection (IT), the standardized covariance between mating success and paternity share (COVMP), mean-standardized Bateman gradients (βM), and the maximum precopulatory selection differential (Jones’ index). Fixed effects are scaled to have a mean of zero and SD of 1 and so are comparable within models. Effects are shown with SEs in brackets; all main effects and interactions were significant at the <0.001 level.