Functional Morphology and Systematics: Studying Functional Patterns in an Historical Context

Abstract

The study of function is a neglected area of systematic and historical biology. Over the last 20 years, systematic biology has expanded to include in its purview the study of many different kinds of patterns, and structural features of all kinds have been the subject of phylogenetic analyses. In addition to macroscopic structural features that have been the traditional source of characters reflecting patterns of ancestry and descent, systematists have increasingly relied on DNA base and amino acid sequences, electrophoretic banding patterns, and ontogenetic sequences of character transformation to sort out genealogical patterns (e.g. 21, 51, 63, 72, 111). Morphological features of organisms have been used by systematists as the basis for biogeographic (120, 157, 158), morphometric (17, 134), ontogenetic (1, 54, 55, 72), and quantitative genetic analyses (130) as well as for studying speciation patterns, and ecological and coevolutionary interactions (18-20, 27, 104). But data on organismal function have been both the least used and the least understood class of information about organisms in systematic biology. There are three main reasons why the form-function relationship, long a central dichotomy in biology (124), has been so heavily weighted toward the