  The two major functions in galaxy evolution that we would like to measure are
the stellar populations in galaxies, and their time-derivative, the star
formation rate. Especially at redshifts above 1, both of these measures are
benefiting greatly from wide-area infrared data. To date, most of these
infrared observations suggest that a significant fraction of the star formation
suffers substantial internal extinction from dust. Ground-based illustrations
include optical/infrared photometric redshift estimates of Balmer-break
galaxies, and near-infrared narrow-band imaging and spectroscopy of emission
lines redshifted from the optical rest frame. Space-based examples include
slitless spectroscopic surveys for H-alpha line emission, mid- and far-infrared
diffuse background measurements and deep number counts, and searches for
starlight from damped Lyman-alpha absorbers.
