Numerical taxonomy is a

classification system Classification is the activity of assigning objects to some pre-existing classes or categories. This is distinct from the task of establishing the classes themselves (for example through cluster analysis). Examples include diagnostic tests, identif ...

in biological

systematics Systematics is the study of the diversification of living forms, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees (synonyms: phylogenetic trees, phylogenies). Phy ...

which deals with the grouping by

numerical method In numerical analysis, a numerical method is a mathematical tool designed to solve numerical problems. The implementation of a numerical method with an appropriate convergence check in a programming language is called a numerical algorithm. Mathem ...

s of taxonomic units based on their character states. It aims to create a

taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

using numeric algorithms like

cluster analysis Cluster analysis or clustering is the data analyzing technique in which task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more Similarity measure, similar (in some specific sense defined by the ...

rather than using subjective evaluation of their properties. The concept was first developed by Robert R. Sokal and Peter H. A. Sneath in 1963 and later elaborated by the same authors.Sneath and Sokal: ''Numerical Taxonomy'', San Francisco: W.H. Freeman, 1974 by Tejanshu Ravesh They divided the field into

phenetics In biology, phenetics (; ), also known as taximetrics, is an attempt to classify organisms based on overall similarity, usually with respect to morphology or other observable traits, regardless of their phylogeny or evolutionary relation. It is ...

in which classifications are formed based on the patterns of overall similarities and

cladistics Cladistics ( ; from Ancient Greek 'branch') is an approach to Taxonomy (biology), biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesiz ...

in which classifications are based on the branching patterns of the estimated evolutionary history of the taxa.{{cn span, In recent years many authors treat numerical taxonomy and phenetics as synonyms despite the distinctions made by those authors., date=May 2017 Although intended as an objective method, in practice the choice and implicit or explicit

weighting The process of frequency weighting involves emphasizing the contribution of particular aspects of a phenomenon (or of a set of data) over others to an outcome or result; thereby highlighting those aspects in comparison to others in the analy ...

of characteristics is influenced by available data and research interests of the investigator. What was made objective was the introduction of explicit steps to be used to create

dendrogram A dendrogram is a diagram representing a Tree (graph theory), tree graph. This diagrammatic representation is frequently used in different contexts: * in hierarchical clustering, it illustrates the arrangement of the clusters produced by ...

s and

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

s using numerical methods rather than subjective synthesis of data.

References

Taxonomy (biology) es:Taxonomía numérica ru:Фенетика

See also

References