  We study the evolution of the low-order moments of the galaxy overdensity
distribution over the redshift interval 0.7<z<1.5. We find that the variance
and the normalized skewness evolve over this redshift interval in a way that is
remarkably consistent with predictions of first- and second-order perturbation
theory. This finding confirms the standard gravitational instability paradigm
over nearly 9 Gyrs of cosmic time and demonstrates the importance of accounting
for the non-linear component of galaxy biasing to avoid disagreement between
theory and observations.
