Fox Animal Phylogenetic Tree Diagrams showcase different evolution stages of a fox starting from Canis Lupus Familiaris, Canis Lupus, Canis Latrans, Canis Rufus, Vulpes Zerda, Vulpes Lagopus, Vulpes, Lycaon Pictus, and more. A phylogenetic tree or evolutionary tree is a diagrammatic representation of the evolutionary relationships among various taxa. As the phylogenetic tree diagram suggests, the major components of such trees are leaves. The leaves of a tree can be species, populations, individuals, or even genes. If the tips represent a formally named group, they are called taxa (singular: taxon). A 'taxon' is a group of organisms at any hierarchical rank, such as a family, genus, or species.