Ricerc@Sapienza

In reconstructing the common evolutionary history of hosts and parasites, the current method of choice is the phylogenetic tree reconciliation. In this model, we are given a host tree H, a parasite tree P, and a function σ mapping the leaves of P to the leaves of H and the goal is to find, under some biologically motivated constraints, a reconciliation, that is a function from the vertices of P to the vertices of H that respects σ and allows the identification of biological events such as co-speciation, duplication and host switch.

We introduce a hybrid metaphor for the visualization of the reconciliations of co-phylogenetic trees, that are mappings among the nodes of two trees. The typical application is the visualization of the co-evolution of hosts and parasites in biology. Our strategy combines a space-filling and a node-link approach. Differently from traditional meth- ods, it guarantees an unambiguous and ‘downward’ representation when- ever the reconciliation is time-consistent (i.e., meaningful).