  We present results from a study to determine how star formation contributes
to galaxy growth since redshift z=1.5. Using galaxies from the MUnich
Near-Infrared Cluster Survey (MUNICS) and the FORS Deep Field (FDF), we
investigate the specific star formation rate (SSFR, star formation rate [SFR]
per unit galaxy stellar mass) as a function of galaxy stellar mass and
redshift. We test the compatibility of our results with a sample drawn from a
larger volume using the Sloan Digital Sky Survey. We find that the SSFR
decreases as galaxy stellar mass increases, suggesting that star formation
contributes more to the growth of low-mass galaxies than high-mass galaxies at
all redshifts in this study. We also find a ridge in the SSFR that runs
parallel to lines of constant SFR and decreases by a factor of 10 from z=1 to
today, matching the results of the evolution in SFR density seen in the
``Lilly-Madau'' diagram. The ridge evolves independently of galaxy stellar mass
to a particular turnover mass at the high mass end. Galaxies above the turnover
mass show a sharp decrease in SSFR compared to the average at that epoch, and
the turnover mass increases with redshift.
