Numerical taxonomy is a
classification system Classification is a process related to categorization, the process in which ideas and objects are recognized, differentiated and understood.
Classification is the grouping of related facts into classes.
It may also refer to:
Business, organizat ...
in biological
systematics
Biological 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: cladograms, phylogenetic tre ...
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
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
Cluster analysis or clustering is the task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more similar (in some sense) to each other than to those in other groups (clusters). It is a main task of ...
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 rel ...
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 char ...
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
dendrogram
A dendrogram is a diagram representing a tree. This diagrammatic representation is frequently used in different contexts:
* in hierarchical clustering, it illustrates the arrangement of the clusters produced by the corresponding analyses.
...
s 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 d ...
s using numerical methods rather than subjective synthesis of data.
See also
*
Computational phylogenetics
Computational phylogenetics is the application of computational algorithms, methods, and programs to phylogenetic
*
Taxonomy (biology)
In biology, taxonomy () is the scientific study of naming, defining ( circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon) and these groups are given ...
References
Taxonomy (biology)
es:Taxonomía numérica
ru:Фенетика