Constructing Parsimonious Hybridization Networks from Multiple Phylogenetic Trees Using a SAT-Solver

We present an exact algorithm for constructing minimal hybridization networks from multiple trees which is based on reducing the problem to the Boolean satisfiability problem. The main idea of our algorithm is to iterate over possible hybridization numbers and to construct a Boolean formula for each of them that is satisfiable iff there exists a network with such hybridization number. The proposed algorithm is implemented in a software tool PhyloSAT. The experimental evaluation of our algorithm on biological data shows that our method is as far as we know the fastest exact algorithm for the minimal hybridization network construction problem.