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TAXONOMIC CONCEPTS
Author(s) -
Cain A. J.
Publication year - 1959
Publication title -
ibis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 80
eISSN - 1474-919X
pISSN - 0019-1019
DOI - 10.1111/j.1474-919x.1959.tb02387.x
Subject(s) - generality , flood myth , computer science , a priori and a posteriori , imperfect , taxon , natural (archaeology) , variation (astronomy) , ecology , geography , epistemology , biology , linguistics , archaeology , psychology , philosophy , astrophysics , psychotherapist , physics
Summary.1 Ray and Willughby fully understood the need for descriptions of different generality for different purposes and (Ray at least) the waste of time caused by excessive accuracy. Their principal problem was to sort out biospecies; they tried also to produce a natural classification. 2 In the time of Linnaeus, a flood of material to be catalogued and identified produced a regression to a keying classification based on a priori principles to a large extent, the natural classifications of the time being very imperfect and inconvenient for identifying. This was the period, unfortunately, when the reference system (binomial nomenclature) was invented which is now internationally accepted. 3 The advent of evolution caused little change in taxonomic practice, the groups formerly elaborated a priori or by natural classification being now called monophyletic and the constant characters being the primitive ones and still important. 4 In the period of the “New Systematics”, continuous variation first became a real practical problem in a system so far devoted to discontinuous variation. It led to three things, a better understanding and description of biospecies, the idea of geographical speciation, and various techniques of differing accuracy and convenience for its description. 5 The present period is characterised by a flood of new characters, as the Linnean was by a flood of new forms. They require proper handling taxonomically (on the lines already worked out for morphological characters) and proper balancing against one another. 6 The problem of comparing wholly different sorts of characters raises again that of quantitative overall comparison in general. This, when achieved, can serve as the basis for phylogenetic weighting. 7 It is suggested that the principal development of taxonomic concepts in the past has been in the recognition of different forms (the species, subspecies, population, and the like) and that in the future those connected with exact comparison will come into prominence (the character, the natural group, etc.).