This is the preferred method of classifying life. Systematics utilizes evidence from all fields of biology, e.g., from morphology, anatomy, chemistry, ultrastructure, behavior, and molecular biology. A cladogram is a branching diagram representing our best estimate of phylogeny. For each member of the whole group, determine characters and character states. TAXA Petal no.
Classification is based on the recognition of monophyletic groups.
Monophyletic - most recent common ancestor plus all known descendants. Reptilia has now been redefined to include birds, making it monophyletic. All living organisms today have evolved an equal amount of time. Humans, birds, lizards, and frogs are all equally closely related to fish. Confusion as to whether you mean time of divergence or number of derived characters.