How a Name is Selected for Binomial Nomenclature

Question

I understand the gist of how to construct a name using the Binomial Nomenclature, but I don't understand how to select a unique name.

My contrived example comes from looking at this:

acaulis: stemless, e.g. silver thistle, Carlina acaulis.

So assuming the naming is <Genus> <Species>, then within the genus say we have 20 species already, which is fairly modest given this description of genus size:

The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles, which have about 1180 genera, the most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5-10 species, ~200 have 11-50 species, and only 27 genera have more than 50 species (see figure). However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus, contains over 3,000 species.

Looking at the Astragalus genus gives some insight to the potential naming conflicts.

But say we have our 20 species in our custom genus. Our genus is called Foo and our species are (translated into Latin):

Yellow
Green
Blue
Shiny
Spotted
...

Now say we discover a new species and the prominent features are that it is both Shiny and Yellow, whereas those previously defined species are only either Shiny or Yellow, not both. So now we have one that is both, and we are having a hard time finding any other distinguishing factors.

One approach would be to call it the Double (diplo-) species, since it is both Yellow and Shiny. So perhaps we add to our list (in Latin maybe "diplopicta")

Foo DualColor (or Foo Diplopicta)

But wait! We already have used this technique (let's say). We look further in the original list and yep it's already there.

Yellow
Green
Blue
Shiny
Spotted
...
DualColor
...

So we can't use that technique. So maybe we go to the location, say it is northern:

Foo NorthernLocation

But wait! We already used that technique too!

Yellow
Green
Blue
Shiny
Spotted
...
DualColor
...
NorthernLocation
...

So now maybe we just try using another feature that we haven't used yet in any of the other species. Maybe this thing also is slightly larger than most of the other ones, and we haven't used Large as a property.

So we add (in Latin):

Foo LargeSize

Then we find some more species and we keep having to try to come up with new ways to get unique names. Maybe we try other things like:

• Specific continent.
• A feature that hasn't been used yet.
• The discoverers name.
• etc.

Already it's kind of brittle feeling.

Now let's say we discover a new species in the genus again. But this one is really really yellow. Way more yellow than the previous one we called yellow. And that is it's only distinguishing feature. I would like to know what is done in this situation.

I would like to know, generally, how this process like described above is handled in practice in the real world.

So we have this new yellow thing. Now we want to rename the old species and use Yellow for this one, and come up with something better for the old one. Not a problem if this information hasn't been shared yet. But if it's already been shared all over the world then you can't really change it, at least not with a long and drawn out, carefully managed process.

So we're stuck with the less than ideal name for our new "really really yellow" thing, and we just end up calling it:

Foo CoreyDiscoverer

But at this point I feel like might as well just give it a number ID since there's not really any meaningful connection (though history perhaps is a good enough connection).

Basically I'm wondering how good names are created for things using the Binomial Nomenclature, and how naming conflicts (or the desire to change names) are handled. The example above outlines a scenario that one might encounter when trying to uniquely name species within a genus, and I am wondering how it is handled in practice.

As an example, from here it reads:

If on the other hand the taxon appears never to have been named at all, then the scientist or another qualified expert picks a type specimen and publishes a new name and an official description.

But it doesn't explain how this works, the issues they had to consider as outlined above.

Answer 1

Your question covers a whole field of research, taxonomy, and the answer to the complexity of the naming process and how conflicts are resolved is the subject of very strict and very detailed rules. For example, the nomenclatural treatment of animals is governed by the International Code of Zoological Nomenclature, while the nomenclature of plants, algae and fungi is governed by the International Code of Nomenclature for algae, fungi and plants (paradoxically, fungi are actually more closely related to animals, but however).

These codes have a series of rules governing the ways that new names can be coined, how new names should be considered against old or preserved names, what constitutes a synonymous name, and hundreds of other little things (for example, the Shenzhen code, the most recently ratified code of the ICN, is very, very long).

Some trivia, which might give you some idea of the conflicts which are handled by the code: under the ICZN, tautonyms, which are species names where both the genus name and species epithet are the same (e.g. Vulpes vulpes, the red fox) are allowed, whereas under the ICN, they are not allowed. Species from separate codes can share the same name (see for example the answers to this question), and two species from different genera governed by the same code can share the same species epithet - it is the binomial combination which must be unique.

I am not kidding when I say the rules are really, really detailed, and the minutiae is too much to get into here. If you read the respective codes, you will get some feeling for the rules which are applied.

In regards to the other part of your question, choosing an appropriate name: this is generally at the discretion of the publishing author (unless the name is invalid under the code, then another author may step in to dispute it or correct it). These can come from all sorts of things, ranging from utterly boring and descriptive to pretty funny and facetious. For example, Han is a monotypic genus of fossil trilobite, and having only one member, its sole species is Han solo.

I suspect the reason that most materials don't discuss how this process really works is because it is really, really complicated and often pretty dry. You'll see plenty of examples of new names being coined in journals like Taxon. But doing taxonomy is often conceived as not very glamorous, so doesn't receive that much attention, even though it underpins most comparative fields like ecology and evolution.

As a final note, the reasons that a species will be included in a given genus, or split into its own genus, or several genera will be lumped together into one large genus, are more murky, and related to phylogeny, morphology, final size, etc. These decisions are often also left up to the discretion of the author, unless of course they conflict with the code.