Too many names, so little time

Divisions in systematics detract from its mission

In 1858, future U.S. president Abraham Lincoln famously said that a house divided against itself cannot stand.  Systematic biology has been verbally sliced and diced so many times that its detractors have been granted license to pick and choose which parts to support, and which to ignore.  This wasn’t the motive for emphasizing one part of systematics over another, but it was the result.

The science that explores and classifies species has more aliases than a post office bulletin board: systematic biology, systematics, phylogenetic systematics, phenetics, taxonomy, evolutionary taxonomy, biological taxonomy, numerical taxonomy, taxonomic monography, molecular systematics, eclectic taxonomy, descriptive taxonomy, revisionary taxonomy, cladistics, and biosystematics, among others.  Small wonder that people are confused about what, exactly, systematics is, that some of its activities are better supported than others, and that its own mission has become less clear.

Some of these names are secret handshakes for preferred assumptions or methods.  For example, phenetics refers to those who prefer to group species based on overall similarity.  Discredited and abandoned by morphologists decades ago, phenetics has reemerged in the context of molecular data.  Some have telegraphed their “population thinking,” confusing the aims of population biology with those of taxonomy, with the name biosystematics.  Others distance themselves from taxonomy which they see as old-fashioned by calling themselves phylogeneticists.

A common distinction is between systematics and taxonomy. The former being associated with evolutionary considerations such as the circumscription of species and the analysis of relationships.  The latter relegated to supposedly dry and boring rules governing nomenclature and classification. There is often a part-to-whole association between these two names for the science.  To some, systematics is the broader field with taxonomy a subset concerned with classification.  To others, it is the polar opposite with taxonomy the broader field with the ultimate aim of a natural classification and systematics a subset that analyzes phylogenetic relationships for that purpose.

There are real world consequences to these definitions and science has suffered mightily because of them.  Teasing out evolution-related activities as systematics has elevated their prestige and attracted funding. At the same time, there has been a decline in reputation, positions and funding for revisionary taxonomy. The late French nematologist Michel Luc and colleagues summed it up as follows:

“Decision makers came to consider taxonomy as a science of the past, one that belongs to museums or that may even not be a science at all.  Consequently, the word ‘taxonomy’ gradually became a ‘dirty word,’ to the extent that any research work including it in its heading would most probably not be funded.”

With extinction raging, and 80% or more species unknown, unnamed, and unclassified, this creates a dangerous situation.  From exciting theories to the most arcane rules of nomenclature, every aspect of systematics is important and interconnected.  Hoping for a taxonomic renaissance, I have resolved to no longer participate in this semantic sophistry.  My forthcoming book, Species, Science and Society, uses the words systematics and taxonomy interchangeably for one and the same science—in all its dimensions.  It is time to reassert taxonomy as a cohesive, independent science, practiced on its own terms, so that we learn all that we can about the diversity and history of species while we still can.

Reference

Luc, M., Doucet, M. E., Fortuner, R., et al. (2010)  Usefulness of morphological data for the study of nematode biodiversity. Nematology, 12: 495– 504.

Wheeler, Q. 2023. Species, Science and Society: The Role of Systematic Biology. London: Routledge.