No name, new game

I just came across a very interesting opinion paper titled “No name, no game” published in the European Journal of Taxonomy.

The paper was written by Yves Samyn of the “Belgian National Focal Point to the Global Taxonomy Initiative” (I think we all agree they need an acronym) and Olivier De Clerck of Ghent University. I’ve known Yves since we were both on a field trip in KwaZulu-Natal (South Africa) many years ago, and Oli is a great colleague and friend who I’ve worked with very closely for over ten years.

They argue that, in contrast to what Joppa et al. (2011) claim, today’s taxonomic workforce is not sufficiently large to describe the remaining pool of missing species within a reasonable amount of time. This is in the first place because much larger numbers of species remain to be described for many understudied taxa than for the well-studied groups of organisms that Joppa et al. (2011) included in their analysis. In addition, the massive numbers of unnamed species in the Genbank and BoLD databases suggest that there is another layer of undiscovered diversity remaining to be characterized (coined “dark taxa” by Rod Page). This is certainly relevant for algae as these unnamed species (e.g. “Rhodymenia sp. 1SA“) are discovered en masse when DNA barcodes are generated and “dark algal species” are accumulating rapidly in Genbank (see figure below; >75% dark taxa in the three main algal groups in 2011). The great majority of these discovered species remain without a proper name because formally describing them is much more laborious than discovering them.

algal dark taxa

Yves and Oli argue that this widening gap between the number of discovered and described species is problematic, focusing their argument on the fact that these newly discovered species do not have names. They argue that scientific names matter for society, for example because legislation (e.g. CITES) uses species names as currency.

While I agree with most of the paper, in particular the part about promoting an increasing role for developing countries in characterizing their biodiversity, I think that Yves and Oli fail to make a convincing case for their “no name, no game” statement. In my opinion, traditional binomials are not needed for legislation to work or for scientists and non-specialists to communicate about species. When the bird flu hit, the specialist as well as the greater audience knew and understood what H5N1 was. Just like professional and amateur astronomers have no trouble communicating about “55 Cancri e”. What would make biologists different? All one needs to communicate about a species is some sort of identifier, not necessarily a formally described species binomial.

When it comes to legislation and conservation, I agree that it is important to be able to pinpoint exactly what is being conserved. But once again, does it need a binomial? Not having to go through the process of describing a newly discovered species would permit that species to be conserved more rapidly. Furthermore, for legislative purposes, diagnosability of the species should be more important than the name of the species. And at least for algae, where DNA data have become the gold standard for species delimitation, DNA sequences are rapidly becoming much more reliable for species identification than morphological keys to named species. While the DNA vs. morphology contraposition should not play a major role in this discussion, it is relevant because the great majority of dark taxa are discovered through DNA sequencing and can future collections can easily be identified as the dark taxon in question with a DNA barcode. In other words, DNA sequencing has changed the game, and because of that I think we should think more along the lines of “no name, new game” instead of “no name, no game”.

Once again, I agree with what Yves and Oli wrote about the taxonomic workforce not being large enough to describe the remaining pool of species in understudied groups within a reasonable timeframe using traditional procedures. As do I agree with most other points made in the paper. But do we really need formal species binomials for all newly discovered taxa? Are there arguments that support the “no name, no game” statement that I have overlooked here? Or arguments in favor of the “no name, new game” alternative that I have not mentioned? I welcome your ideas in the comments.

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  1. Paul Gabrielson said:

    To name or not to name, that is the question. As an old school morpho-taxonomist, that part of me says, “of course we have to use validly published names”; as a practicing molecular systematist who currently is surprised and inundated by the number of undescribed macro-marine algal taxa in the well-worked NE Pacific flora, I am more sympathetic to alternatives to the binomial nomenclature I still adhere to. But I have become increasingly frustrated with slow pace of that work, as I am overwhelmed by how much we don’t know. At present, I am focused on coralline algae, a group in the NE Pacific I thought would benefit from the fresh approach of DNA sequencing, and that has proved to be true. But I now find myself hoping that a specimen I have sequenced will match a sequence already in my database and not be new. There are too many undescribed species to be characterized, and we are just scratching the surface.

    As Samyn & De Clerck (2012) have pointed out and reinforced by Heroen’s red algal graph, the number of “dark taxa” is increasing steadily, and, I believe, will increase at a greater rate in the next 5-10 years with intensive collecting coupled with bar-coding. But these so-called “dark taxa” at least have an identifier, a DNA sequence. For these dark taxa not having a generic name and specific epithet is a sin of omission that is easily rectified over time by providing a name. What is more troubling, to this traditional taxonomist, is the sin of commission, the assigning of a validly published name to a sequence when there is no clear link to the type specimen on which the name is based. There are many of these in GenBank, and they are far more misleading than a generic name followed by sp. Equally troubling is that many of these named sequences lack a voucher specimen, which means their identity cannot be verified. It is better to not name a sequence in a public database than to provide a name about which one is not certain. Correcting these is more difficult and time consuming than assigning unknown sequences a name, once the identity of the sequence is known. Let’s err in naming with sins of omission rather than those of commission.

    Paul Gabrielson
    Herbarium Research Associate
    University of North Carolina, Chapel Hill

    • Marie Pazoutova said:

      Yes, indeed! The mess in Genbank is like the rise of “wild capitalism” in Mid/Eastern Europe right after the fall of communist regimes: the process bursted spontaneously and was quicker than our ability to recognize we need some rules and regulations…

      I think we do need the binomials. More than 200 years of science was done with them. I guess that leaving the names would cause more problems than keeping them.
      The problem is not whether to leave them or not, but how to reconcile the traditional system with the modern (that will be out-of-date again in few decades!). And, subsequently, how to set the ultimate (ultimate? for how long?) species concept and decide at which level we allow the splitting of cryptic species or – the other way round – unifying and merging. And also: are we able to set thes rules to be applied universaly accros the whole eukaryotic (at least) web of life (leaving the bacteriologists aside)?

      • Gary Saunders said:

        Interesting and controversial topic – here are my own dogmatic opinions. Does a species need a name (?) – absolutely! Must it be an ICBN-compatible binomial (?) – absolutely not! A species identifier could be based on any form of alpha and/or numeric label so long as there is global adoption of that system. It could even be a DNA sequence from an agreed upon marker. My preference would be that every species receive a unique number from its initial entry into a database. In the ideal world that database would be an internationally accredited/ recognized genetic database, with the sequence data diagnostic of that species rather than used as the unique identifier itself. BOLD loosely does this by assigning collections to genetic bins, each with a unique identifier (Cluster number). Taxonomists could then go about their business of assigning names, correcting names, transferring species, etc., under the Linnaean binomial system (let’s face it, Claudea elegans is far more eloquent than, for example, “TH45238ug437”). Regardless to the nomenclatural and taxonomic chaos that may ensue, that unique number would remain attached to that ‘species’ thus making it very easy for non-taxonomists to compare data between studies, databases, etc., without having to be fully conversant with the taxonomic literature. This is a pragmatic approach that bridges the romance of the pre-molecular age of ‘Linnaean’ taxonomic discovery with the contemporary DNA-driven age of discovery.

  2. Several things seem to be coming out of this discussion. The first is that sequence data make taxonomy computable. We can assign specimens to taxa with an associated measure of confidence, and we can do this on a massive scale (e.g., DNA barcoding). A challenge is connecting sequence data with existing taxonomy (assuming that we want to do that, perhaps in some groups we might argue it would be better to start afresh). Given the amount of “dark taxa” we are going to struggle to do this using names alone. Specimens are another way to do this, but this requires that we have vouchers, and ideally vouchers that have globally unique identifiers so that we can link sequences, specimens, and data on those specimens (e.g., papers that cite those specimens as part of a taxonomic study). We are some way from being able to do this, but perhaps the rise of dark taxa will focus people’s minds on this task.

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