  In a companion paper we outlined a methodology for generating parameter-free,
model-independent ``no-evolution'' fields of faint galaxy images, demonstrating
the need for significant evolution in the HDF at faint magnitudes. Here we
incorporate evolution into our procedure, by transforming the input bright
galaxy images with redshift, for comparison with the HDF at faint magnitudes.
Pure luminosity evolution is explored assuming that galaxy surface brightness
evolves uniformly, at a rate chosen to reproduce the I-band counts. This form
of evolution exacerbates the size discrepancy identified by our no-evolution
simulations, by increasing the area of a galaxy visible to a fixed isophote.
Reasonable dwarf-augmented models are unable to generate the count excess
invoking moderate rates of stellar evolution. A plausible fit to the counts and
sizes is provided by `mass-conserving' density-evolution, consistent with
small-scale hierarchical growth, where the product of disk area and space
density is conserved with redshift. Here the increased surface brightness
generated by stellar evolution is accomodated by the reduced average galaxy
size, for a wide range of geometries. These models are useful for assessing the
limitations of the HDF images, by calculating their rates of incompleteness and
the degree of over-counting. Finally we demonstrate the potential for
improvement in quantifying evolution at fainter magnitudes using the HST
Advanced Camera, with its superior UV and optical performance.
