Taxonomic schools

The phenetic and phylogenetic principles are the two fundamental types of biological classification, but there are more than two schools of thought about how classification should be carried out. We can discuss three main schools.

1. Cladism is the common term used for classification based on the phylogenetic principle, although the term phylogenetic systematics is sometimes used.

2. Numerical phenetics. This is the most influential modern school of phenetic classification. The terms phenetics, numerical phenetics and numerical taxonomy are used interchangeably.

3. Evolutionary classification: a synthesis of phenetic and phylogenetic methods.

Table: phenetic, evolutionary and cladistic classification can be distinguished by the characters they use to define groups, and the kinds of groups they recognize. The meaning of these terms will be explained.