Taxonomy’s rightful place in history

Wednesday, March 11th, 2009 | History of Science, Personalities

A talk given last February 13 by paleontologist Niles Eldredge in Lisbon perfectly exemplified the general opinion regarding how little role Taxonomy played in the development of the modern Theory of Evolution. Already in a hurry after spending too much time talking about Darwin’s childhood, he reached a slide showing some barnacles and said “oh, by the way, Darwin spend some time on the taxonomy of barnacles, but this didn’t have any relevance to the development of his theory”, next slide. That was it. Taxonomy is but an unnecessary extra slide in the history of evolutionary biology. To be fair to Eldredge, his talk entitled “Darwin: Discovering the Tree of Life” was not an specialized talk but rather was meant for the general public of all ages wondering what was all the excitement about Darwin this year.

In a paper published today in the journal Taxon, historian Mary P. Winsor asserts that, in telling the history of the Theory of Evolution, Taxonomy has been unfairly left out. Most of the history written about Darwin, and still often repeated, is that he had his theory of natural selection ready when he wrote his Sketch of 1842, and after that he just sat down on it for almost two decades before publishing the Origin of Species in 1859 after receiving a wake-up letter from Alfred R. Wallace. However many historians have now argued that those sixteen odd years were crucial in shaping Darwin’s theory and that, rather than been in isolation during those years, he actively sought the latest scientific achievements in natural history in an attempt to formulate a refined theory capable of synthesis¹. For many 1800′s naturalists, transmutationists or not, the taxonomic arrangement of groups within groups was such an achievement that provided evidence that organism were truly related to one another. One obstacle in appreciating this simple reading of history is that, for us twentieth-first-century-evolutionists, it is hard to imagine how can someone think of organism as truly related to each other if not phylogenetically.

Winsor ask the reader to see the conceptual relationship between taxonomy and Darwin in an analogous (homologous?) way to the relationship between the work of Copernicus and that of Newton. Darwin, like Newton, set himself the task of providing a causal explanation, a process, capable of explaining the patterns in Nature. And in the same way that the accepted work of Copernicus on planetary motions provided the patterns to be explained by Newton, so for Darwin the accepted patterns crying for explanation, the tree of life alluded in the title of Eldredge’s talk, came from Taxonomy. Darwin’s theory of evolution had to be able to explain the occurrence of groups within groups, it had to be able to account for divergent evolution.

Presented in this clear way, the importance of taxonomy seems so straightforward and unproblematic that one may ask why wasn’t this accepted before? Winsor points to the by-now usual suspect: the essentialism story. This is the view first articulated by Ernst Mayr and followed by many since that maintains that taxonomists before Darwin were victims of a severe case of typological thinking, believing each species has an essence, and thus committing them to fixity of species. After Darwin, the story goes, everyone just got smarter². Winsor work in the last few years has shown that this is a distorted view of history.

Winsor’s paper is a nice addition to a body of growing literature by historians and philosophers reexamining the natural sciences made in the 1800′s and bringing taxonomy, morphology and embryology to their rightful places in history.

Addendum: Read more about Mary P. Winsor’s paper on Evolving Thoughts, including Darwin’s consideration of the then popular Quinarian system.

References and notes

Winsor, Mary P. (2009). Taxonomy was the foundation of Darwin’s evolution Taxon, 58 (1), 43-49

Ospovat, D. 1981. The development of Darwin’s Theory. Natural History, Natural Theology & Natural selection 1838–1859. Cambridge University Press, Cambridge. ↩
Or, if you believe Ghiselin, taxonomists still don’t get it, Ghiselin, M. 1997. Metaphysics and the Origin of Species. State University of New York Press, Albany. ↩

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Tags: Charles Darwin, Mary P. Winsor, Taxonomy, Typological thinking

5 Comments to Taxonomy’s rightful place in history

Laelaps
March 12, 2009

“oh, by the way, Darwin spend some time on the taxonomy of barnacles, but this didn’t have any relevance to the development of his theory”

Yikes. It’s not like Darwin spent years on barnacles, studying their minute variations. Surely that didn’t matter at all to the development of his theory.

Thank you for writing this post. Have you read Fortey’s “Dry Storeroom No.1″? I didn’t particularly care for it, but he too makes the case that taxonomy is vitally important to other areas of biological/evolutionary science.

Roberto Keller
March 12, 2009

I remember when Fortey’s book came out, but had forgot about it. I’m definitely getting myself a copy now after your recommendation.

Polly Winsor
March 17, 2009

Actually, I basically agree with Eldgridge that Darwin’s intensive studies of barnacles were not relevant to the development of his theory, because almost all the elements of the theory were present before he undertook that work, as the 1842 and 44 sketches show. This is broad-brush history, of course, and we do know that his “principle of divergence” came in the 50s, and was something he was very pleased about (the idea that ecological pressures select for greater difference and so encourage the branches to veer apart). Still, the point of my paper was that branching evolution, which he became convinced of in 1837, was a response to naturalists’ perception that the hierarchical format codified by Linnaeus mostly expressed nature’s own order. (Certainly not the format alone, but the weird parallels to it in biogeography, paleontology, and embryology!)
No question but that the barnacle work vastly encouraged Darwin, because their morphology, embryology, and variability confirmed what his theory had supposed, but if his theory had an essence (!!!), it was in place by 1842.
Thanks for noticing my paper. (Incidentally, my full name is Mary Pickard Winsor, but I happily go by my nickname, Polly (a traditional variant of “Molly”).

Roberto Keller
March 17, 2009

Polly.- Your comments and clarifications are most welcome. Thank you for stopping by!

P.S. I was indeed excited when I learnt that Owen’s Limbs was recently reprinted.

Mats Envall
March 19, 2009

Excuse me, Roberto, but I was a little confused by your reasoning here and your comment on John Wilkins’ blog. On this posting you appear to acknowledge (Polly’s argument for) taxonomy’s (i.e., classification’s) importance and priority to process explanations, whereas you on John Wilkins’ blog appear to prefer induction to falsification as a scientific method, although induction views (as Mill clearly states it) classification as “subsidiary to induction”. These two preferences appear incompatible, since “prior” is clearly distinguished from “subsidiary”. Or, do you see any overlap between them in or over time?

(BTW, John does in his posting about Mill discuss the difference between what in multivariate statistics is called class respectively segment, and otherwise often is called infinite respectively finite classes. Taxa are clearly segments, that’s actually the problem that makes paraphyletic groups necessary: there’s no single pass between two points in a multidimensional space that is shorter than all other passes, i.e., no single “most parsimonious” pass).

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