Taxonomy: discovery or just description?

Recently there was a thread on twitter about whether taxonomy really is discovery because the species were ‘discovered’ or collected before and are currently in a museum collection. The response tweets were pretty interesting in asking the definition of ‘species’ or ‘discovery’ and that there are ‘different avenues to discovery’. This thread concluded with saying that ‘perhaps describing and naming is indeed true discovery’. I agree with that statement but taxonomy goes beyond just describing and naming; you must recognize that it’s something different.

That thread made realize that 1) I miss describing and naming species, haven’t published a taxonomic paper in a few years and 2) the incredible feeling of excitement when I recognize something as a new species or genus. I want to write about the latter. The best way to write about it is going through the process. You can start in the field with collecting specimens but it really starts once you’re looking at the specimens under a miscroscope (I’ll focus on insect collections because that’s where my expertise lies). To take you on this journey of discovery, I’ll use, as an exampled, one of the genera that Terry Wheeler and I described – Allomedeia (Mlynarek and Wheeler 2010).

During my MSc, I was working on the systematics and phylogeny of the tribe Elachipterini; a tribe of chloropid flies that have really cool morphological diversity. I was basing most of my work on already known species and building a morphological matrix to present a hypothesis of their evolutionary relationships. I was armed with literature and descriptions and had access to specimens from three collections (the Lyman Entomological Museum and research laboratory, the Canadian National Collection and the Collection at the Smithsonian).

As I went through these collections, I noticed in one of the drawers an additional label under a series of specimens saying “Elachiptera?”; I picked up the unit tray and had a close look under the microscope. Indeed, they did look like they could belong to the tribe, but something was different about them and I couldn’t place the differences just then. Although based on the label note these were probably new species but members of the species rich genus Elachiptera. These specimens could have easily been overlooked so I think that entitles it to Discovery #1; the discovery of the specimens in the collection that were left there in the past and seemingly forgotten waiting for an eager student. I checked these specimens against descriptions that I already had, against other specimens that they could possibly be, they didn’t match anything so I definitely had new species (Discovery #2). I proceeded to make my measurements and describe the species morphology, their color, and their diagnostic characters from antenna to tip of abdomen. The more I looked at them, the more I was convinced that they were indeed part of the tribe Elachipterini but didn’t belong to a particular genus. Based on the specimen differences, I had 5 species. Once the external descriptions were completed, I dissected the genitalia (as a side note: a dissection of a fly is not as hard as it sounds, you cut part of the abdomen off, and clear it in lactic acid then place it into glycerin to have a closer look at the genitalic structures under a compound scope – I apologize for the crude description to those that do it every day). I placed the slide under the scope and my first reaction to what I saw was “that’s SO weird!” Why? The male genitalia did not look like any of those of any other member of the Elachipterini. The second thought was “maybe this is a mutant male, I better dissect another one”; same thing! All the males of these 5 new species had similar genitalic characteristics. My excitement grew – I have (potentially) a new genus (Discovery #3)! Later the phylogeny of the tribe Elachipterini confirmed that indeed it could be considered a new genus. [A side note: Allomedeia comes from Greek, allo meaning ‘different’ and medos meaning “genitals” (Mlynarek and Wheeler 2010)].

So even though I didn’t collect these specimens, although I would have liked too considering they were collected from South Africa, I re-discovered them in a drawer and, as a taxonomist, recognized them as different from other described species. I think that’s discovery in every sense of the word. Just because somebody put them there and I described and named them doesn’t mean I did not discover them. Taxonomy shouldn’t be considered just description and naming.

When I’m working on a project, I feel like a little kid because, based on my taxonomic experience, I never know what to expect; maybe the next specimen I rear from my goldenrod will be a new species (stay tuned…)! The key is that you have to be attuned and ready for anything – it could happen.

Reference

Mlynarek, J.J. and Wheeler, T.A. 2010. Systematics of Allomedeia, a new genus of afrotropical Chloropidae. Annals of the Entomological Society of America 103(4): 465-471.