Kim-Vy Tran
	University of Zurich

Abstract: By combining multi-wavelength observations of galaxies
spanning the range in redshift and environment, we can identify the
physical mechanisms and timescales for transforming the field
population into the passive early-type galaxies that dominate local
clusters.  I will summarize our recent work showing that 1) the most
massive galaxies in groups and clusters can form at z<1 via
dissipationless merging; 2) dusty star formation is enhanced in galaxy
groups at intermediate redshifts; and 3) there is an increasing
fraction of dust-obscurred star formation with increasing redshift in
galaxy clusters (0<z<0.8).  Our observations show that the group
environment is critical for understanding how galaxies evolve from
active to passive systems.