Table 1 . Per-generation rates of change in control mean phenotype, and among-line variance, over the three life-history assays.

Trait	Mean	Variance
Size at maturity (mm)	0.0001 (0.0066)	0.0000 (0.0000)
Clutch size	−0.0536 (0.1000)	−0.0179 (0.1100)
Age at maturity (days)	0.0099 (0.0059)	−0.0089 (0.0100)

Reported values are coefficients for regressions on generation number; standard errors are given in parentheses. Estimates for clutch size represent an average value of the separate analyses of clutches 1–4. None of the estimates deviates significantly from zero. The variance for size at maturity was <10⁻⁴.