  Pan-chromatic galaxy surveys are providing tightening constraints on the
global mass assembly history, and high-resolution imaging of large fields is
telling us when and where stars were formed. How well are state-of-the-art
hierarchical galaxy formation models currently doing at reproducing these
observations? I present results here that suggest that hierarchical models are
doing quite well at reproducing the global star formation and stellar mass
assembly history obtained from galaxies selected in the optical and Near IR.
However, the same models fail to reproduce two very important populations at
high redshift: quiescent red spheroids and vigorously star-forming,
dust-enshrouded starbursts. This mismatch carries important lessons about how
star formation is triggered and regulated in early galaxies, and may force us
to consider new ideas about the formation of massive spheroids.
