A snail by any other name is a slug: Culture, nature and classification

By Kirsten Bell

Since moving to the UK nine months ago, I have finally acquired a small garden – something I have lived without for most of my adult life. Having grown up in the tropics, I was therefore relatively unfamiliar with the scourge of gardeners everywhere: slugs and snails. However, this lack of exposure has been speedily rectified, because it soon became apparent that our tiny backyard was subject to a snail and slug plague of biblical proportions. Each day we were greeted by the sight of glistening trails of criss-crossing slime and the carcasses of overpriced plants from Homebase.

One weekend, deciding enough was enough, I committed what I’m pretty sure the Snail Wrangler would characterise as a wanton act of snail slaughter. After reading up on how to rid oneself of slugs and snails, armed with a spray bottle of vinegar and a bucket of heavily salted water, I went to the garden to finish them off. More than 70 slug and snail deaths later, and having witnessed the death throes of dozens, I was convinced, like many of my internet brethren, that they are basically the same creature. As far as I could see, the primary difference was the shell, which, in any case, the snails seemed to divest themselves of in their final moments, suggesting that it was more of an accessory than a necessity.[1]

I innocently (and somewhat unwisely) made this observation over lunch the following week to a table full of biological anthropologists and zoologists, who proceeded to treat it with all the respect they felt such a statement was due. Not one to concede defeat lightly,[2] and undeterred by a wholesale ignorance of zoology and biology, I questioned why the snail’s ‘house’ should be the difference that makes a difference, especially when in all other respects they are basically identical – from their general shape and size (those antennae!) to their eating habits and sexual proclivities (both are hermaphrodites[3]). And so began a lengthy (and ongoing) debate that can be summarised as follows:

Them (in shocked tones, because the social anthropologist clearly has no understanding of biology): A snail is not a slug because they evolved differently.

Me (after a speedy internet search and having discovered a new term): but aren’t both gastropods?

Them (now amused): that’s like saying a human is like an elephant because both are mammalia.

Me (realising that I’m slightly out of my depth and need to turn the conversation around to subject matter I’m actually familiar with): Yes, but you’re assuming that zoological taxonomies are objective and neutral, but all systems of classification – even scientific ones – are cultural.

Them (realising that mockery is the best response): This seems right up your alley–

The debate ultimately hinged on the relationship between the science of taxonomy and what are generally called ‘ethnotaxonomies’ and ‘folk taxonomies’. In his book The Order of Things, Michel Foucault provides what is perhaps the most fantastical and infamous[4] example of the latter. Citing Jorge Luis Borges, he quotes ‘a certain Chinese encyclopedia’, in which it is written that:

Animals are divided into: (a) belonging to the Emperor, (b) embalmed, (c) tame, (d) suckling pigs, (e) sirens, (f) fabulous, (g) stray dogs, (h) included in the present classification, (i) frenzied, (j) innumerable, (k) drawn with a very fine camelhair brush, (l) et cetera, (m) having just broken the water pitcher, (n) that from a long way off look like flies.

As Foucault observes, ‘In the wonderment of this taxonomy, the thing we apprehend in one great leap, the thing that by means of the fable is demonstrated as the exotic charm of another system of thought, is the limitation of our own, the stark impossibility of thinking that’.

Taxonomies, as expressions of systems of thought, have long been of interest to anthropologists and sociologists. From Émile Durkheim to Claude Lévi-Strauss (and a vast number of scholars in between), anthropologists have explored the different ways in which societies classify and understand the world around them. One such illustration is Ralph Bulmer’s study of zoological taxonomy amongst the Karam of the Papua New Guinean highlands, titled ‘Why is the cassowary not a bird?’ His central preoccupation in the paper is the ambiguous status of the cassowary, which the Karam place in its own taxonomic category. Bulmer observes that the Karam have an ‘enormous, detailed and on the whole highly accurate knowledge of natural history’, and that at a base level, their taxonomy is based on morphological differences, differences in habitat, feeding habits, etc., that broadly correspond to scientific taxonomies. However, at its upper level, ‘objective biological facts’ no longer dominate – something most evident in the status of the cassowary, which, Bulmer argues, can be explained not just by the cassowary’s anomalous features, but by its unique cosmological relationship with humans.

Although Bulmer affirms a contrast between scientific taxonomies as based on ‘nature’ and the Karam taxonomy as based on ‘culture’, the more recent ontological turn in anthropology[5] has challenged this distinction entirely. This is a key focus of my colleague Istvan Praet’s book Animism and the Question of Life, where he critiques the assumption that the science of biology describes life as it really is while animistic beliefs (typically glossed as the attribution of life to non-living things) are merely a social construction or cultural perception. As the proponents of the ontological turn have shown, this opposition between nature and culture quickly gets us into all sorts of conceptual trouble based on the other dualisms it entails – between science and society, the objective and subjective, and facts and values.

Now, this is not to invoke a form of – ahem – ‘trumped’ up post-truth politics, or to suggest that we can no longer speak of facts, or that science is wrong, or any of the other knee-jerk reactions that often accompany social scientists’ efforts to talk of science as constructed. Instead, the point is that classification is not a neutral act. To quote Geoffrey Bowker and Susan Leigh Star’s book Sorting Things Out: Classification and Its Consequences: ‘each standard and each category valorizes some point of view and silences another’. However, this is much more difficult for us to see in biological taxonomies than in their ‘ethno’-taxonomic variants, because we are so used to thinking of the former as describing life as it really is.

Contemporary biological taxonomies have their roots in the framework proposed by the Swedish naturalist Carolus Linnaeus (a.k.a. Carl von Linné), whose Systema Naturae introduced his system of classifying the natural world, which was organised on the basis of resemblance and aimed to reveal God’s Master Plan.[6] It was Linnaeus who was responsible for binominal nomenclature:[7] a naming system where each organism is ordered hierarchically within a kingdom, class, order, genus and species. Writing a century later, Charles Darwin saw in Linnaean taxonomy not just resemblance as an organising principle, but the propinquity of descent: the underlying bond between organisms that was typically hidden by various degrees of modification and that he suggested was made partially manifest in Linneaus’s system. With the rise of evolutionary theory came the development of phylogenetic classification, leading to further refinements in biological taxonomies – a cause aided by Willi Hennig’s work on cladistics.[8]

In sum, contemporary biological taxonomies are based on three core principles: resemblance, hierarchy and ancestry. Now, resemblance sounds straightforward enough as an organising principle, but, as the snail/slug example shows, choices must be made about what resemblances and differences actually count. It’s worth noting that Linnaeus’s choices for determining plant taxonomies were heavily criticised by his contemporaries. According to Patricia Fara in her book Sex, Botany and Empire: The Story of Carl Linnaeus and Joseph Banks, Linnaeus was accused of building an elaborate botanical taxonomy on the basis of relatively unimportant features. While earlier botanists had grouped plants by characteristics like the shape of their leaves or the colour of their flowers, Linnaeus chose to order them based on their sexual dimorphism instead. According to Fara, ‘The prejudices of Enlightenment Christian moralists are built right into the heart of this scientific plan for plants, which Linnaeus outlined by using words such as “bride” and “marriage”’.

Likewise, his introduction of the term ‘mammalia’, literally meaning ‘of the breast’, raised more than a few eyebrows, given its abrupt departure from the prevailing terminology of the period (Quadupedia). As the historian Lorna Schiebinger notes, although the term Quadupedia had various problems, the presence of milk-producing mammae is one of a variety of characteristics shared by the animals Linnaeus placed in this category; indeed, others are arguably superior for the purposes of classification, being shared by both sexes and better accounting for egg-laying mammals (e.g., hair). Schiebinger argues that Linnaeus’s choice of terminology can be explained primarily by the gender politics of the period. It’s no coincidence, she suggests, that a trait associated primarily with females, who were themselves seen as closer to nature, was chosen to encapsulate the links between humans and other animals, whereas the term Linnaeus used to differentiate humans as a species – Homo sapiens – literally meant ‘man of wisdom’. In her words, ‘within Linnaean terminology, a female characteristic (the lactating mamma) ties humans to brutes, while a traditionally male characteristic (reason) marks our separateness’.

This brings us to ancestry and hierarchy, which, post-Darwin, have become a privileged aspect of biological taxonomies (to wit, a slug is not a snail because they evolved differently). But prioritising ancestry is no more ‘natural’ than prioritising some other basis for comparison – again, remember Bowker and Star’s point that ‘each category valorizes some point of view and silences another’. In fact, it’s arguably intensely ‘cultural’ (see the problem with these terms?) because ancestry must be largely inferred. This is evident in the hominid/hominin taxonomy debate and the recognition of its consequences for the perceived relationships between humans and other primates.

Moreover, while a taxonomy based on ancestry might be helpful in answering the sorts of questions biologists are interested in asking, it’s not a particularly useful system outside the rarefied circles of science, because it cannot tell us the things we actually want to know: such as what’s edible and what isn’t, and what terms are most suitable for abusing our neighbours (and why ‘cow’ works better for this purpose than ‘lemur’). We, in common with every other society in the world, have well-developed taxonomies for these – some of which are detailed in my colleague Garry Marvin’s co-edited book The Routledge Handbook of Human-Animal Studies.

Ultimately, taxonomies reflect the values, concerns and interests of the groups who create them – whether the taxonomy in question is of the biological, ethnological or folk variety. Moreover, the choices made about what to prioritise are always that: choices. This, I would suggest, is why gardeners so frequently submit Google queries around whether snails and slugs are actually different. Based on the ways we engage with them, where their similarities vastly outweigh their differences (from the damage they wreak to how best to dispose of them), the shell itself, well, that’s not much of a difference at all.

Acknowledgements: I could not have finished this piece without the help of the inimitable Todd C. Rae, who gave me a crash course in biological taxonomy and patiently answered questions that I’m fairly certain his first-year students would have been embarrassed to ask. It goes without saying that any errors in my overview of biological taxonomy are, well, Todd’s obviously, so all criticisms and requests for clarification should be directed to him rather than me.

Notes:

[1] Now, I will admit to being somewhat confused on this front as the Snail Wrangler insists that snails can’t divest themselves of their shells – although I think we can safely assume that a woman who regularly gives talks on ‘marvelous mucus’ has never sprayed them with acid and rubbed salt in their wounds (which is how one of my colleagues described my approach to snail disposal). Thus, while snails might not be able to live without their shell, it follows that they can certainly die without it.

[2] Or at all.

[3] If watching two slime-covered creatures getting sexy to the dulcet tones of a David Attenborough voiceover is your thing, you can learn more about their mating habits here.

[4] Oft-quoted, the list is of questionable provenance. According to Wikipedia, many of Borges’ works featured pseudo-references that resulted in a mix of facts and fiction – so, in that respect, much like Wikipedia itself.

[5] Ontology, a word rarely used by anthropologists 15 years ago, is now flung around with abandon at any social anthropology conference.

[6] With a Type A personality to surpass all others, Linnaeus was apparently fond of saying that ‘God created, Linnaeus organised’ (that he liked to refer to himself in the third person bespeaks a giant ego to match his giant ambition).

[7] Contra the entirety of the internet, Todd insists that it should be pronounced binominal rather than binomial nomenclature, so in order not to incur his wrath that is the spelling I use here.

[8] A term I pretended to understand when Todd first used it, but quickly realised did not, as I had originally assumed, refer to the art of cladding a house.