Maximum parsimony method is used to build phylogenetic tree both from protein as well as DNA sequences.Phylogenetic tree is basically build by working out evolutionary relationship between different species.The maximum parsimony method is based on the fact that we build a phylogenetic tree based on the minimum no. of evolutionary events.For more on this method read http://ab.inf.uni-tuebingen.de/teaching/ws06/albi1/script/phylogeny_31Jan2007.pdf