  In this paper, we test the age matching hypothesis that the star formation
rate (SFR) of a galaxy of fixed stellar mass is determined by its dark matter
halo formation history, and as such, that more quiescent galaxies reside in
older halos. This simple model has been remarkably successful at predicting
color-based galaxy statistics at low redshift as measured in the Sloan Digital
Sky Survey (SDSS). To further test this method with observations, we present
new SDSS measurements of the galaxy two-point correlation function and
galaxy-galaxy lensing as a function of stellar mass and SFR, separated into
quenched and star-forming galaxy samples. We find that our age matching model
is in excellent agreement with these new measurements. We also employ a galaxy
group finder and show that our model is able to predict: (1) the relative SFRs
of central and satellite galaxies, (2) the SFR-dependence of the radial
distribution of satellite galaxy populations within galaxy groups, rich groups,
and clusters and their surrounding larger scale environments, and (3) the
interesting feature that the satellite quenched fraction as a function of
projected radial distance from the central galaxy exhibits an ~ r^-.15 slope,
independent of environment. The accurate prediction for the spatial
distribution of satellites is intriguing given the fact that we do not
explicitly model satellite-specific processes after infall, and that in our
model the virial radius does not mark a special transition region in the
evolution of a satellite, contrary to most galaxy evolution models. The success
of the model suggests that present-day galaxy SFR is strongly correlated with
halo mass assembly history.
