Classification

Classification is the arrangement of organisms, or groups of organisms, into distinct categories according to a particular, well-established scheme, based on the similarities and dissimilarities among them. Depending on what the scheme is built on, classification can follow one of three broad approaches:

• Artificial classification relies on a handful of easily observable, non-evolutionary features — such as habit or colour — often without regard to true biological relationship. The system devised by Linnaeus is a classic example.
• Natural classification is built on characters that are objectively significant, rather than chosen purely for convenience. Bentham and Hooker's system of plant classification is an example of this approach.
• Phylogenetic classification groups organisms according to their common evolutionary descent. Engler and Prantl's classification is an example. …