  Galaxy evolution during the last 9 Gyr is discussed. It can be traced back
from well known present-day galaxies or directly observed for galaxies at
different look back times. This requires clear and consistently matched
selection criteria for galaxy samples. There is a net decrease of rest-frame,
UV luminosity density, at least since z = 1. It is interpreted as an important
decline of the star formation since the last ~9 Gyr. A similar trend is found
for the evolution of the IR luminosity density which accounts for heavily
extincted starbursts. Interestingly the global star formation density, after
including IR selected galaxies, is twice the value of estimates based on the UV
luminosity density, and this holds from z=0 to z=1.
  Large disks are not contributing much to the observed decrease, which is
mainly related to significant changes with the epoch in the distribution of
galaxy morphologies. A significant fraction of the global star formation occurs
in luminous galaxies which are apparently small or in interacting galaxies
detected in the deepest IR or radio surveys.
