at first pass this approach is an unavoidable reduction on complexity. On the other hand in a hierarchical Universe with the assembly of the structures, the galaxies evolve and move, tending towards denser regions with time, while the environments change too, thus what we actually observe is [*galaxy evolution in an evolving environment*]{}.

The most massive structures in the local Universe are superclusters, which are still collapsing with galaxy clusters and groups frequently interacting and merging, and where a significant number of galaxies are encountering dense environments for the first time. The relative dynamical immaturity of superclusters and the presence of infalling dark–matter halos make them ideal laboratories to test the predictions of hierarchical mass assembly models, and in particular on galaxy evolution. Superclusters are not so rare systems in the Universe [see @SD11]. The observations of superclusters is often considered a challenge to the hierarchical structure formation paradigm since such extreme dense structures, but also voids, are not reproduced by the $N$-body simulations. @YBA11 pointed out that the reason of this discrepancy can be due to the method used to assess the probability of finding such events in the distribution of cold matter. They proposed a new technique to 