Top panels: evolutionary tracks. Bottom panels: evolutionary diagrams. Left panels: skewness S₃. Right panels: kurtosis S₄. In the evolutionary tracks, the symbols along the tracks from the left are for redshifts z = 30, 10, 5, 3, 1, and 0. In the evolutionary diagrams, the symbols from top to bottom correspond to smoothing lengths 2, 4, 8, and 16 h⁻¹ Mpc. The solid black curves show the cosmological skewness S₃ and kurtosis S₄ according to the log-normal distribution. The dotted curves show the predictions of the perturbation theory Eq. (11).