Species

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by John Hartigan (The University of Texas at Austin)

Species is a means for thinking both the stability and mutability of life forms. Species mark stabilized “moments”—sometimes over eons—as organisms transition from one discernible, reproducible form to another. Species organize varying degrees of internal variation—genetic and phenotypic—over against external constraints or resources that distinctly locate these life forms. Though the focus is often on specifying life, taxonomically species are reminders of the commonalities across genera, of the enormous amount of overlap in how life diversifies into multitudinous forms. Not just constitutionally (longevity, fertility, disease-resistance, etc.), but behaviorally as well. For taxonomists, species are a hypothesis, a speculation that a certain combination of morphology, behavior and location constitutes one of these unique tips of a genera. Species, then, are a point at which thought pauses in considering life, recognizing the import of form; focusing on the tension between diversity and uniformity, before scaling temporally through the vast expanse of time or spatially across the immensity of the planet.

A basic question highlights the complexity of species: how many are there? After 250+ years of the taxonomic project, that question is not yet answerable. With some 1.2 million species currently cataloged, there may yet be more than 8.7 million eukaryotic unidentified species globally, of which approximately 2.2 million are marine (Mora et al. 2011). The challenge of knowing species is utterly immense. Then there is the problem of the selective bias informing the ones we do know scientifically, highlighting the culturally contoured basis of human attention to species. With carnivores, for instance, the implicit criteria for warranting study seems to be body and range size: larger, abundant, and in frequent contact with humans (Brooke et al. 2014). Small ones, isolated in politically unstable or inhospitable regions, leaning towards omnivorous diets, are much less studied. Bears get a lot of attention; skunks do not. “Charismatic” species draw additional focus from recent mobilizations of “citizen-scientists” to produce data on overlooked species, an effort that likely will do little to whittle down the vast number of entirely unknown life forms.

The next question is how do we conceptualize this plethora of life forms? Here matters are no less challenging. There are dozens of ways to conceptualize species. One current count comes up with 26 definitions. Broadly, these can be parsed between two orientations: biological (interbreeding life forms that produce fertile offspring) or phylogenetic (less restrictively, those with a shared, unique evolutionary history). The core issue in both is how resemblance is maintained, sexually or genetically. Yet the clarity of these two definitions often obscures the fuzziness that occurs at the boundaries: the kinds of odd sex at the fringes of a species, and the sometimes surprising flow of genes that come unbound from a lineage and travel outside of the form. These two views produce one set of answers to the question, “where do new species come from?,” relying upon mutations to explain it. But symbiosis between species, resulting in the acquisition and transferal of genomes—as in polyploidy with plants—suggest this answer is far too reductive (Margulis and Sagan 2003). Then, too, there is a fault line between realism vs nominalism—do natural kinds or universal types really exist—and, of course, eternally, between splitters and lumpers. All this is further complicated because different disciplinary kinds of taxonomists—botanists, bacteriologists, and zoologists—work at distinct scales and so have contrasting criteria of resolution, refinement, and distinction in delineating species.

This last point highlights the fact that any species concept reflects knowledge projects, alternately distinct, overlapping, or competing. These projects turn on developments in our scientific capacity to discern and perceive life forms—new technologies of surveillance and sampling, such as barcoding species, as well as new techniques of analysis and ordering, such as by satellite mapping. Yet broadly, these all can be subsumed under “the taxonomic project”—an endeavor, roughly starting with Linnaeus, to categorize all life on the planet. This project has transformed at key moment, such as with Darwin and evolutionary theory; then with “Modern Synthesis” in biology which added genes to the equation. Today, the initial imagining of this project as a largely disinterested, objective affair is giving way to concerns over biodiversity. As well, biogeography is rendering species less as fixed types by looking at speciation through geologic time, seeing form as contoured by biome—gradations of latitude, elevation, and isolation: habitat. With biodiversity, a concept coined by E.O. Wilson, the impetus is the pressing recognition that species are rapidly going extinct; a trend that promises to be a defining feature of the Anthropocene (Kolber 2014). Biogeography, conversely, focuses on the dynamism of species as they change and generate hybrids while they move through space and across time. Notably, in both fields, though, we see varieties of species types emerge: new units such as “flagship,” “umbrella,” “keystone,” or “indicator” species. These each embody a view of the inter-relatedness of species and their imbricatedness in particular biomes. As well, these types each entail a notion of surrogacy, whereby one species does more than just represent another or many others; its value operates in relation to (unknown and perhaps unknowable) species, each similarly entangled within distinct, rapidly changing, perhaps endangered biomes.

Biodiversity, as a framing of species, helps elaborate the underlying complication in all this, mentioned briefly above: the human interests that guide the very effort to know and catalog life. In this regard, the taxonomic project arrives rather later on the scene, and never entirely displaces what might be called, alternately, the “totemic project,” which for millennia has found species both “good to think” and useful for delineating social distinctions among overly similar humans. Claude Lévi-Strauss classically accounted for the manifold ways people have used species to articulate abstract renderings of their social interests and concerns—especially with identifying (individually) and dis-identifying as groups, clans, or moieties (Lévi-Strauss 1966). Totemism, of course, exists among us “moderns,” too; just ask stockbrokers about “bears and bulls.” But there seems to be something distinctively new in the heraldry of flagship species operating to mobilize social campaigns. Consider the kinds of publics arrayed around species today. Associations of “friends” are gelling around charismatic species–organizing  publics that are engaged in conservation work, or sometimes gathering people up in consumerist dreams. Is this an extension of biosociality as we have defined it in relation to humans or something of a different order? I lean toward the latter in considering “plant publics” in Europe (historically and currently) as efforts to rewrite the nation via biome (Hartigan 2015).

I offer the concept of “species formation,” which I take indirectly from Marx’s “social formation” and more immediately from Michael Omi and Howard Winant’s notion of “racial formation.” Species formation highlights the artifactual status of species without construing them as only social constructions or relegating them to representations. Species formation is attentive to the boundary work of life forms—internally and externally—asking how modes of recognition and encounter, mediated through variously limited or overlaps of sensoriums, may be guided by certain etiquettes, particularly at the most remote temporal and spatial extension of species. This concept engages the irreducibility of the social in constituting humans’ interests in species, while also recognizing that the sociality we once thought made us so unique is actually quite active through many other life forms—from mammals to plants, or consortia of bacteria.

In the end, the “species problem” is not something to resolve but rather the means of recognizing and taking stock of humans’ expanding yet limited capacity to think about life itself (Stamos 2013). Proliferating species concepts reflect heightened human interests and increased perceptual capacity to purview life forms, as well as the inexorable question of our representational sensibilities, fixations, and limits.

There is no end to the “species problem.” The term “multispecies” reminds us that many of these life forms are hopelessly (or happily) entangled and interdependent, but it just as well serves as reminder of the muddled mess generated by efforts at conceptualizing species. Take plants, for instance: to thrive they depend upon mycorrhiza to colonize their roots; angiosperms are generally dependent upon cadres of pollinators to reproduce.

At its root, species are discernible forms animated by life.

References

Mora, Camilo, Derek P. Tittensor, Sina Adl, Alastair G. B. Simpson, and Boris Worm. 2011. “How Many Species Are There on Earth and in the Ocean?” PLoS Biol 9 (8).

Brooke, Zoe M., Jon Bielby, Kate Nambiar, and Chris Carbone. 2014. “Correlates of Research Effort in Carnivores: Body Size, Range Size and Diet Matter.” PLoS ONE 9 (4).

Kirksey, Eben. 2015. “Species: A Praxiographic Study” Journal of the Royal Anthropological Institute, DOI: 10.1111/1467-9655.12286.

Margulis, Lynn, and Dorion Sagan. 2003. Acquiring Genomes: A Theory Of The Origin Of Species. First Edition edition. Princeton, N.J.: Basic Books.

Kolbert, Elizabeth. 2014. The Sixth Extinction: An Unnatural History. First Edition edition. New York: Henry Holt and Co.

Lévi-Strauss, Claude. 1966. The Savage Mind. The University Of Chicago Press. Descola, Philippe. 2013. Beyond Nature and Culture. Chicago ; London: University of Chicago Press.

Hartigan, John. 2015. “Plant Publics: Multispecies Relating in Spanish Botanical Gardens,” Anthropological Quarterly, 88 (2).

Vince, Gaia. 2011. “An Epoch Debate.” Science 334 (6052): 32–37.

Laland, Kevin, Tobias Uller, Marc Feldman, Kim Sterelny, Gerd B. Müller, Armin Moczek, Eva Jablonka, et al. 2014. “Does Evolutionary Theory Need a Rethink?” Nature 514 (7521): 161–64.

Stamos, David N. 2013. The Species Problem: Biological Species, Ontology, and the Metaphysics of Biology. Lexington Books.

John Hartigan: UTexas profile
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a companion to the book