Peter F Stevens

Peter Stevens’ research interests are in two main areas: Malesian flora, especially that of New Guinea; and in phylogenetic/monographic studies (currently mostly in Clusiaceae, also Ericaceae). He has also developed strong interests in history of systematic biology, especially the period 1750-1900, in systematic theory, especially the issue of data in systematics and delimitation of character states, and in the relationship between cognitive psychology and systematic theory and practice, past and present. In general, he tries to understand just what it is that morphological systematists do, whether sight-identifying herbarium specimens or performing phylogenetic analyses. This understanding will help improve the practice and also clarify how the whole systematic endeavor relates to other branches of biology and to the public at large.

His more theoretical and historical concerns are intimately linked to practice— hence work in one area often has implications in others. Thus debates over species limits in the 19th C mirror current discussions over species limits in the Malesian region. The main issue is under what conditions does the systematist see discontinuities used to delimit species. Resolution of this issue has fundamental implications for biodiversity and ecological studies; in some genera, the number of species recognized may be wrongly estimated by a factor of two or more.

Hence there is no conflict between these different concerns, except there is not enough time in the day to follow up all their ramifications. It is both interesting and sobering to see how often apparently quite different issues in the history of systematics and in current practice reduce to the problem posed by continuity and our attempts to solve it— which are all too often confounded by the fact that we have not fully realized the extent of the problem.

Over the last decade in particular, he has become involved in what may loosely be called attempts to develop consensus in taxonomy. Hence my involvement with the Angiosperm Phylogeny Group, which is promoting a consensus classification for flowering plants. With the technical advice of Hilary Davis, Stevens developed and have since (in the last seven years) run the Angiosperm Phylogeny website. This uses the Angiosperm Phylogeny Group classification and attempts to provide a current summary of the understanding of seed plant phylogeny at the level of generic groupings and above.

314-516-6215