Numerical taxonomy is a classification system in biological systematics which deals with the grouping by numerical methods of taxonomic units based on their character states. It aims to create a

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

using numeric algorithms like cluster analysis rather than using subjective evaluation of their properties. The concept was first developed by

Robert R. Sokal Robert Reuven Sokal (January 13, 1926 in Vienna, Austria – April 9, 2012 in Stony Brook, New York) was an Austrian-American biostatistician and entomologist. Distinguished Professor Emeritus at the Stony Brook University, Sokal was a member ...

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 ( el, phainein – to appear) , also known as taximetrics, is an attempt to classify organisms based on overall similarity, usually in morphology or other observable traits, regardless of their phylogeny or evolutionary re ...

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

cladistics Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived cha ...

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 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 analysis. That i ...

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 dendrograms and

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

s using numerical methods rather than subjective synthesis of data.

References

Taxonomy (biology) es:Taxonomía numérica ru:Фенетика

See also

References