  We present some results of the new MORGANA model for the rise of galaxies and
active nuclei, and show that the improved physical motivation of the
description of star formation and feedback allows to get hints on the physical
processes at play. We propose that the high level of turbulence in star-forming
bulges is at the base of the observed downsizing of AGNs. In this framework it
is also possible to reproduce the recently obtained evidence that most
low-redshift accretion is powered by relatively massive, slowly accreting black
holes. Besides, we notice that many galaxy formation models (including MORGANA)
fail to reproduce a basic observable, namely the number density of 10^{11} Msun
galaxies at z~1, as traced by the GOODS-MUSIC sample. This points to a possibly
missing ingredient in the modeling of stellar feedback.
