phylogeny
22.0.6 Phylogeny, Cladistics & Cladogram Modern taxonomy is based on many hypotheses' of the evolutionary history of organisms, known as phylogeny. As with the Scientific Method, scientists develop a hypothesis on the history of an animal and utilise modern science and technology to prove the phylogeny. Cladistics is a classification system which is based on phylogeny. Expanding on phylogeny, cladistics is based on the assumption that each group of related species has one common ancestor and would therefore retain some ancestral characteristics. Moreover, as these related species evolve and diverge from their common ancestor, they would develop unique characteristics. Such characteristics are known as derived characteristics The principles of phylogeny and cladistics can be expressed visually as a cladogram, a branching diagram which acts as a family phylogenetic tree for similar species. A cladogram can also be used to test alternative hypotheses for an animal's phylogeny. In order to determine the most likely cladogram, the derived characteristics of similar species are matched and analysed.