  We present a mark correlation analysis of the galaxies in the Sloan Digital
Sky Survey using weights provided by MOPED. The large size of the sample
permits statistically significant statements about how galaxies with different
metallicities and star formation histories are spatially correlated. Massive
objects formed a larger fraction of their stars at higher redshifts and over
shorter timescales than did less massive objects (sometimes called
down-sizing). We find that those galaxies which dominated the cosmic star
formation at z~3 are predominantly in clusters today, whereas galaxies which
dominate the star formation at z~0 inhabit substantially lower mass objects in
less dense regions today. Hence, our results indicate that star formation and
chemical enrichment occured first in the denser regions of the Universe, and
moved to less dense regions at later times.
