The Significance of Phylogenetic Classifications for Systematic and Evolutionary Biology

Abstract

Systematic biologists have engaged in a long-standing debate over the purposes and methods of classification. Many nonsystematic biologists probably look upon the resulting contentiousness with amusement, if they look upon it at all, for if we are honest about the present condition of systematic biology, we have to admit that classification is often seen as little more than the description and cataloging of nature, as stamp collecting in the minds of many. And when one looks objectively at the debate among the phylogeneticists, evolutionists, and pheneticists, much of it must seem as being highly irrelevant to a nonsystematist. While we might expect this reaction from molecular or cell biologists, its ubiquity also within the field of evolutionary biology is surprising. This apathy towards systematics can be attributed to two factors. First, systematic biologists have done an inadequate job of conveying the importance of classification, and thus the necessity and relevance of systematic studies for biology as a whole. If systematics has something to contribute, then systematists themselves must take some responsibility for communicating that contribution. The second reason is simply that many evolutionary biologists are intellectually lazy, and lack curiosity or desire to investigate for themselves what systematics might have to offer. If population ecologists, they may claim to be interested in the ecological analysis of evolutionary mechanisms: what, they might ask, could classification contribute to that? If population geneticists, they may claim to be concerned with the mechanisms of population change or of speciation: what could classification contribute to that? If physiologists, behaviorists, or biochemists, they may be interested in how organisms adjust evolutionarily to their environments: what could classification contribute to that?