phylogeny, the history of the evolution of a species or group, especially in reference to lines of descent and relationships among broad groups of organisms. Fundamental to phylogeny is the proposition, universally accepted in the scientific community, that plants or animals of different species descended from common ancestors. Phylogenetic status is the study of the evolution of species or groups of organisms or a specific characteristic of an organism. Share Studying evolutionary relationships among biological entities, such as species or individuals, is the primary goal of phylogenetic status. The phylogenetic tree of animals depicting the evolution of animal organs is a special phylogeny example. It shows animal phylogeny is terms of the evolution of animal organs. In this type of diagram, the evolutionary relationship of major animal lineages can be inferred based on the organ level of organization.