A Cladist is a systematist who seeks a natural classification: some comments on Quinn (2017)
In response to Quinn (Biol Philos, 2017. https://doi.org/10.1007/s10539-017-9577-z) we identify cladistics to be about natural classifications and their discovery and thereby propose to add an eighth cladistic definition to Quinn’s list, namely the systematist who seeks to discover natural classifications, regardless of their affiliation, theoretical or methodological justifications.
KeywordsArtificial classification Natural classification Augustin P. de Candolle Carl Linnaeus Gareth Nelson Systematics
Derived from various permutations of phylogeny, biology, philosophy, methodology, sociology, loyalty etc., Aleta Quinn recently proposed “seven specific definitions that capture distinct contemporary uses” of cladistics (Quinn 2017, p. 1). Our own efforts, based on the same criteria, yielded a further seven, which we do not intend to bore our readers with here. We are sure more could be found and more people could be found who subscribe/correspond to them. Suffice to say, one might find definitions for anything—and in any case, Quinn was clear about her motives: “I do not intend to classify individuals, ideas, or research programs. Rather, I clarify distinct things that speakers mean by the term ‘cladist’” (Quinn 2017, p. 1). Depending on one’s outlook—philosopher, historian, biologist, even sociologist (Hull 1988)—the definitions might help progress their subject. As biologists, we found much to think about but rather than dissecting the minutiae, we seek to clarify by attempting to simplify.
Consider the concept of a cladogram, which everyone might agree is a branching diagram commonly included as part of the results of a cladistic analysis. One might derive from this diagram which taxon is more closely related to itself than to any other. One might explain this relationship by common descent. The cladogram, however, need not be constructed with any evolutionary assumptions in mind; rather, the evolutionary assumptions serve to explain why one taxon is more closely related to itself than any other.
“What that theoretical foundation may have been [in reference to de Candolle’s view on characters] is not relevant to my points about contemporary systematics, whose conceptual framework presupposes the concept of evolution” (Quinn 2017, footnote 11).
These words, not readily accessible, were spoken by Gareth Nelson after receiving the Linnean Gold Medal and re-cast above as part of the 2001 Annual Review of the Linnean Society, London. Linnaeus as the first of the moderns? Among other matters, Linnaeus spoke of the differences between artificial and natural classification, a subject taken up and developed by de Candolle (1913). One might cast that debate in very simple terms: artificial classifications are found by imposition, natural classification is discovered. Imposition implies some method or motivation to erect a particular classification, such as a field guide or handbook for identifying specimens—today it is more likely those would be websites, or online interactive guides. There is nothing wrong with artificial classifications. We both use them all the time, almost every day (https://www.trilobites.info/; http://naturalhistory.museumwales.ac.uk/diatoms/). But whatever merits they have, and there are many, they are created by acts of imposition. We ask our readers, then, if they would consider analysis of some data with one or another statistical program, or with one or another parsimony program, or with one or another phenetic program, whether this is an act of imposition or an act of discovery? We see it as an act of imposition. How could it be otherwise? Cladistics, then, is about discovery, about finding repeating patterns, finding the same relationships, finding relationships that are not method dependent, finding relationships that are reflections of the world as it is:
“For the last 50 years and more—even now continuing into the realm of nomenclature—in the name of the modern and the new, Visionaries aim, as it were, to confine the past to a dustbin of history, and to bolt and lock the lid upon it. As if without it, we be in some way better, even born again more whole-some; as if Carl Linnaeus really were among the last of the Ancients, and not, rightly, the first of the moderns, and so related to us—of a group inclusive of us” (Annual Review of the Linnean Society, 2001).
For us, cladistics is about natural classifications and their discovery, an activity that occurs with or without “knowledge of process”. Look in museums, herbaria, universities and other institutions that still hire systematists and you will see:
“What, then, of cladistics in relation to the history of systematics? If cladistics is merely a restatement of the principles of natural classification, why has cladistics been the subject of argument? I suspect that the argument is largely misplaced, and that the misplacement stems, as de Candolle suggests, from confounding the goals of artificial and natural systems” (Nelson 1979, p. 20).
Cladist (viii): A cladist is a systematist who seeks to discover natural classifications.
- Candolle AP de (1913) Théorie élémentaire de la botanique; ou, Exposition des prinicpes de la classification naturelle et de l’art de décrire et d’étudier les végétaux. Déterville, ParisGoogle Scholar
- Ghiselin MT (1969) The triumph of the Darwinian method. University of California Press, BerkeleyGoogle Scholar
- Laudan L (1977) Progress and its problems. University of California Press, BerkeleyGoogle Scholar
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