Know what a phylogenetic tree represents and what it is used for Solution Phylogenetic tree is a graphical representation of the evolution trend of a organism or group of organisms based on the similarities and dissimilarities. The basic idea behind the phylogenetic tree construction is that how the organisms of different kind originated and evolved from common ancestor. If is called phylogenetic tree because, starting from the ancestor it branches out to different species or organisms and the representation looks like a tree with lot of branches. Phylogenetic tree is also called as evolution tree..