1973 NumericalTaxoThePrinciplesAndPractOfNumClassific

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On a chart showing the development of numerical taxonomy in the first chapter of this book the authors characterize 1963 as the year of publication of their own "Principles of Numerical Taxonomy" [HcA 35, 280]. This was indeed a pioneering work on the subject, and the present volume is an extensively revised, updated and expanded version of it, sufficient to justify a change in title and in the ordination of the authors' names."Principles" have disappeared from the main title but are still prominent in the development. This is surely right, since most of the "practices" are carried out by computer. The authors insist on a phenetic rather than a phyletic or cladistic basis for taxonomy, and maintain the superiority of a polythetic approach to classification, that is, that attributes of the taxonomic units should be incorporated simultaneously into the scheme rather than one at a time. Perhaps more controversial is the principle that all attributes should be equally weighted when used for classification. However, two distinctions should be drawn. Firstly, weighting is correctly distinguished from standardization of attributes to unit range or variance, which is often desirable. Secondly, the word "classification" is restricted to the formation of taxa and does not include identification, the assignment of taxonomic units to predefined taxa. Identification and discrimination techniques are the subject of a completely new chapter, in which weighting of attributes, as in discriminant analysis, and monothetic methods, especially taxonomic keys, play an important part.hNumerical taxonomy has developed so greatly over the last ten years that the book is now necessarily more of a reference work than its predecessor. There is an extensive bibliography, and two very useful appendices of references, to applications and techniques respectively. The chapters on phylogeny and population phenetics are new, and non-biological applications of numerical taxonomy also merit a chapter, though hardly long enough to cover the increasing use of clustering and discrimination techniques in a wide variety of applications.iThe central part of the book is chapters four and five. In chapter four, the whole range of similarity and dissimilarity coefficients is surveyed and compared. This is in general well-presented, although the practice of converting all attributes into two-state characters seems to be unnecessarily emphasized in view of methods now available for combining quantitative, multi-state and two-state characters into a single coefficient. Chapter five describes clustering and ordination techniques, again as a survey of methods in use. The different effects of using different methods are informatively presented, and the distinction between ordination and clustering kept clear. The traditional nomenclature for taxonomic rank is abandoned in favour of the "phenon", to which is attached a quantitative measure of similarity.tSome experimental scientists may well be daunted by a book which expects of the reader "some knowledge of statistics and of elementary set and graph theory, as well as of matrix algebra", especially when the authors' own presentation of the mathematics is occasionally careless. (The matrix algebra, in fact, plays only a minor role and can be passed over fairly easily). However, numerical taxonomy is here to stay, and the more numerate will find the book a valuable guide to the state of the subject today.K.J. MARTIN.eADDITIONAL ABSTRACT:In this new, re-organized text [RAM 43, 3114] the authors present an up-to-date theoretical basis for numerical taxonomy and discuss its aims, procedures and applications, both biological and non-biological. There is an extensive appendix listing publications on application to biological systematics, a 60 pp. bibliography and author and subject indexes.ADDITIONAL ABSTRACT:This book replaces Principles of Numerical Taxonomy, published by the same authors in 1963, and deals also with applications, both in biology and in other fields. There is an extensive bibliography and an appendix listing biological taxa (including ca. 10 tree genera) to which numerical taxonomic methods have been applied.



 AuthorvolumeDate ValuetitletypejournaltitleUrldoinoteyear
1973 NumericalTaxoThePrinciplesAndPractOfNumClassificPeter H. Sneath
Robert R.Sokal
Numerical Taxonomy: The Principles and Practice of Numerical Classificationhttp://www.cabdirect.org/abstracts/19730310919.html1973