The name Orestias elegans refers to both a species of pupfish and orchids. Such ‘hemihomonymy’ (when a plant and an animal share a Linnaean name) poses obvious problems when storing data connected to these groups and making it available for users searching for data by species name. This way, it poses a challenge to bioinformaticians and database managers. It also poses a challenge for scientists searching, retrieving and using these data. Similarly, homonymy could make legal documents with species names ambiguous, and in this way hinders the work of conservationists and trade regulators. Finally, it may confuse amateur naturalists that use observation databases hoping to find a location to spot a species they haven’t ticked off their list yet. The case of O. elegans illustrates that the problem of taxonomic disorder is a complex one with causes, implications and potential solutions spread out over areas that are the research subject of different fields. One of the main aims of our research project was to bring together insights from the different scientific disciplines relevant to taxonomic disorder, and put them to work to understand and resolve such problems.
Such interdisciplinary work is hard, not in the least because it requires knowing what’s going on in a range of different fields of research. The only way to do it, then, is to gather specialists from different fields to work together. So this is precisely what we did; we invited experts from different fields for an interdisciplinary workshop on taxonomic disorder. With WORMS database manager Leen Vandepitte, phytopathologist Jolien Venneman, philosopher/historian Joeri Witteveen, evolutionary biologist/governance proponent Frank Zachos, taxonomist Thierry Backeljau, conservationist Peter Paul van Dijk, and systematist/species eliminativist Brent Mishler as well as all project members and various other attendants present, we had a remarkably heterogeneous group. This mix worked great though – whereas taxonomists and philosophers are supposed to be notoriously quarrelsome when it comes to research on (the nature of) biological species, we had two very productive days of discussions without quarrels and fundamental agreement about various core themes.
One such theme was that ‘taxonomic disorder’ is probably not the most accurate term for the subject of our research. Disagreement in taxonomy is likely to be productive in many cases, and even when it isn’t, it is unlikely that associations with illnesses or ‘the breakdown of peaceful and law-abiding public behaviour’ are desirable. Instead, Peter Paul proposed ‘taxonomic turbulence’. While not perfect either – it doesn’t cover uncertainty, for example – the connotations are friendlier and the alliteration makes it sound a lot more pleasant.
Another theme that met with full agreement among participants was that ranking taxa often requires an executive discussion. This lies at the basis of much taxonomic turbulence, and is nearly impossible to eliminate if we want to stick to using species as a special rank. If we do stick to using species, it was proposed, the second best option would be to be very transparent about ranking decisions: which concepts is used to delimit species, what method is used to operationalize this concept, and which thresholds are used for ranking decisions. This way, even if calling something a species doesn’t always mean the same thing, at least readers will know what is meant by calling that particular group a species. Some even argued that such transparency should come in the shape of preregistration of taxonomic research, and we’re planning to write a paper on that subject soon. A final recurring theme was that a large part of what makes taxonomic turbulence hard to resolve, is that it is caused and maintained by sociological factors. It seems pretty clear that the Linnaean system is imperfect and lies at the basis of much taxonomic turbulence. However, changing the system or dropping it is very difficult because it is rooted deeply in the research traditions and heritage of taxonomy. Our optimistic takeaway from this is that our own research methods, which focus on sociological factors, are the right way to go for this project.