  In hierarchical cosmologies the evolution of galaxy clustering depends both
on cosmological quantities such as Omega and Lambda, which determine how dark
matter halos form and evolve, and on the physical processes - cooling, star
formation and feedback - which drive the formation of galaxies within these
merging halos. In this paper, we combine dissipationless cosmological N-body
simulations and semi-analytic models of galaxy formation in order to study how
these two aspects interact. We focus on the differences in clustering predicted
for galaxies of differing luminosity, colour, morphology and star formation
rate and on what these differences can teach us about the galaxy formation
process. We show that a "dip" in the amplitude of galaxy correlations between
z=0 and z=1 can be an important diagnostic. Such a dip occurs in low-density
CDM models because structure forms early and dark matter halos of 10**12 solar
masses, containing galaxies with luminosities around L*, are unbiased tracers
of the dark matter over this redshift range; their clustering amplitude then
evolves similarly to that of the dark matter. At higher redshifts bright
galaxies become strongly biased and the clustering amplitude increases again.
In high density models, structure forms late and bias evolves more rapidly. As
a result, the clustering amplitude of L* galaxies remains constant from z=0 to
1. The strength of these effects is sensitive to sample selection. The dip is
weaker for galaxies with lower star formation rates, redder colours, higher
luminosities and earlier morphological types. We explain why this is the case
and how it is related to the variation with redshift of the abundance and and
environment of the observed galaxies. Studies of clustering evolution as a
function of galaxy properties should place strong constraints on models.
