  We have performed a series of N-body experiments on Connection Machine-5 in
order to simulate the formation of galaxy clusters gravitationally dominated by
a massive dark background. In accordance with previous authors we find an
extremely inhomogeneous evolution where subcondensations are continually formed
and merged. The final distribution of galaxies is more centrally condensed than
that of dark matter particles. We have analyzed the origin of this galaxy-dark
matter segregation and also the origin of subclustering leading to this effect.
We have then analysed, analytically and numerically, the dependence of final
segregation on the physical parameters characterizing the model of
protocluster. We also find that such a segregation persists even when inelastic
encounters of dark halos around galaxies are taken into account. We conclude
that this effect cannot be in general avoided in any hierarchical clustering
scenario.
