Botanical systematics 1950‐2000: change, progress, or both?

<div class="line" id="line-23"> Biosystematics, the study of variation patterns and evolution at the species level and below, flourished In the 1950s. Higher evolutionary level studies, however, were stalled because there was no convincing way of hypothesising relationships. Phenetic systematics developed in the late 1950s as a critique of both the goals and methods of evolutionary systematics, its own goals being those earlier stated by Gilmour (1940: 472, emphasis in original): &ldquo;A natural classification is that grouping which endeavours to utilise&nbsp; <i> all&nbsp; </i> the attributes of the individuals under consideration, and hence is useful for a very wide range of purposes&rdquo;. Phenetic computer&hyphen;assisted analyses of data became popular. Nevertheless, many systematists were specifically interested in phylogenies. By the late 1970s several methods that produced hypotheses of phylogeny were in use; they emphasised the possession of shared, derived characters. Since then variants of parsimony&hyphen;based Hennigan analyses have remained popular. With the influx of molecular data&mdash;a flood after 1990&mdash;and the development of methods that estimated aspects of support for branches of phylogenetic trees, a radical overhaul of higher&hyphen;level relationships got underway. Analyses of species&hyphen;level patterns of variation were less popular during much of this period, and the process of description of species has remained largely unchanged. However, computer&hyphen;based interactive keys and multi&hyphen;purpose descriptive databases may fundamentally affect this area of our business. During the last 50 years some kinds of systematic work have become highly cooperative and systematics as a whole is a much more unified discipline, even as some more traditional areas of botanical systematics seem largely static if not in regress.</div>