Lines that lead back to the same line represent species that share a common ancestor. Be sure to study these until you can see that all are the same. In this exercise you will need to be able to interpret phylogenetic tree diagrams drawn by different people in different ways. Taxonomy is the name given to the study of classification of organisms based on their phylogenetic relationships. In making a phylogenetic classification, taxonomists name groups of organisms that are all close relatives of one another.
Classification schemes are hierarchical in nature.
Large groups containing many different species are divided into smaller more specific groups, each with fewer species. Each of these is divided into still smaller groups with still fewer species. These groupings reflect phylogenetic relationships. There are seven traditional major levels in a classification scheme. Every organism is placed into one of five kingdoms.