Angle between different periods. Histogram and density curve of the distribution of the angle (θ) between different periods. θ obtained by a resampling procedure, between the first principal component (eigenvector) of both matrices of (co)variance for traits measured in hermaphrodites (total, early and late fertility, and growth) between two periods G 1 (generations 1–4) vs. G 2 (generations 4–10); and G 2 vs. G 3 (generations 13–22). We used this procedure for the populations from control, uranium and salt environments. Error bars denote 95% confidence intervals for θ obtained using a resampling procedure.