cladistics

biology

Also known as: phylogenetic systematics

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 16, 2026

Quick Summary

Cladistics is a method of classifying organisms based on shared, uniquely derived characteristics that reflect their evolutionary relationships. This approach arranges taxa in a branching hierarchy, where all members of a group share the same ancestors. Unlike older classification systems that might group organisms by general similarity, cladistics focuses on identifying shared derived traits (synapomorphies) that distinguish a group from its ancestors.123

Phylogenetic trees are diagrams that visually represent these evolutionary relationships, showing how different groups are connected through common ancestors. A monophyletic group, or clade, includes an ancestor and all of its descendants. This method aims for objectivity by inferring evolutionary history through testable hypotheses about shared ancestry.4526

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

6 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

evolution
Maximum parsimony methods
…parsimony methods are related to cladistics, a very formalistic theory of taxonomic classification, extensively used with morphological and paleontological data. The critical feature in cladistics is the identification of derived shared traits, called synapomorphic traits. A synapomorphic trait is shared by some taxa but not others because the former inherited…
Read More
…parsimony methods are related to cladistics, a very formalistic theory of taxonomic classification, extensively used with morphological and paleontological data. The critical feature in cladistics is the identification of derived shared traits, called synapomorphic traits. A synapomorphic trait is shared by some taxa but not others because the former inherited…
Read More

phylogeny
Phenetics versus cladistics
The methodology of phylogenetic work rests on two approaches at present: numerical taxonomy (phenetics) and phylogenetic systematics (cladistics). The most-direct difference between the two methods is that phenetics classifies species by using as many characteristics as possible and arranges them by similarity regardless of…
Read More
The methodology of phylogenetic work rests on two approaches at present: numerical taxonomy (phenetics) and phylogenetic systematics (cladistics). The most-direct difference between the two methods is that phenetics classifies species by using as many characteristics as possible and arranges them by similarity regardless of…
Read More

Willi Hennig
…the leading proponent of the cladistic school of phylogenetic systematics.
Read More
…the leading proponent of the cladistic school of phylogenetic systematics.
Read More