Numerical phenetic taxonomy and its heuristic aspects

The principal multivariate methods used in numerical taxonomy and their gra phic representations are outlined. Advantages of, and problems with, numeri cal taxonomy and the definition of phenetic taxonomic characters, recent us e of ultrastructural, biochemical and genetic tools and their application t o taxonomy, and elucidation of non-cosmopolitanism and speciation is discus sed. The application of a combination of molecular and numerical methodolog ies is recommended. The capability of numerical taxonomy to reveal new know ledge is explored. It could lead to recognition of multiple correlations hi dden in the data, to ordination of populations, and the use of phenetic des criptors in defining multidimensional niches.