Listen up, aspiring and practicing scientists of Tumblr. I’m gonna asplain you a thing.
Everyone with a high-school education should be aware of some simple facts:
- Life forms have been divided into groups of increasing similarity & relatedness:
- This can be remembered with a simple mnemonic:
This view is simplified. You would not be expected to see anything more complicated without getting a degree in a biological field.
Let me explain some more of the more complicated intricacies:
- Actually, there are also Super-, Sub- and Infra- groups of most of these classifications.
You are almost certainly familiar with some of the subgroups. For instance, ‘Crustacea’ is a Subphylum.
- Sub-, super-, and infra- groups can be ignored without consequence, but do help us to organise and understand relationships.
- These group are usually erected to deal with very complicated taxonomy that would be too simple under traditional separation.
- When the specific levels are unclear (like when the evolutionary history is so complex that we can’t figure out where to draw the lines), the term ‘Tribe’ is often used. This means very little until true groupings can be assigned, but helps us to organise a bit.
There are very strict rules governing how taxonomic names are composed, set out in the International Code of Zoological Nomenclature. Most of these are too complex for me to get into, but at a simple level:
- Family names always end in -idae (e.g. Iguanidae, Canidae, Felidae etc.)
- Subfamily names always end in -inae (e.g. Boophinae, Mantellinae, etc.)
NB: The rules of Botanical Nomenclature are different! They follow the International Code of Nomenclature for algae, fungi, and plants.
- Plant family names always end in -aceae (e.g. Orchidaceae, Iridaceae, etc.)
- Plant subfamily names always end in -oideae (e.g. Orchidoideae, Vanilloideae, etc.)
There are some rules about how these things are formatted.
- All levels except species are always capitalised.
Species is never capitalised. Thus, Pan Troglodytes is wrong, while Pan troglodytes is right.
- Genus and species are always italicised (note: no other levels are ever capitalised).
For instance, Ailurus fulgens is correct, while Ailurus fulgens is not.
- Subgenus, when it exists, is always placed in brackets between genus and species. Subgenus is never treated as full genus - while you can call a species by Genus species or Genus (Subgenus) species, you can never call a species by Subgenus species.
So Boophis (Sahona) pauliani and Boophis pauliani are both correct, but Sahona pauliani is never correct.
- After it has been given its full name once, a species may be referred to by an abbreviated form: the first letter of its genus, followed by its species name.
So I may now refer to Boophis pauliani as B. pauliani. This is not completely necessary, and it is bad practice to insist upon always abbreviating after the first instance. A happy medium must be found, where the full name is brought in occasionally. This usually happens at the start of a sentence.
It should be noted that when working with several species from different genera which either have the same first initial (e.g. Boophis madagascariensis and Brookesia perarmata), or the same species name (e.g. Boophis madagascariensis and Phelsuma madagascariensis), abbreviation may not be the right way to go. Clarity is key.
Species names are usually one of three things:
- A description of the species’ appearance or habits, usually using Latin, Greek, or other languages, but almost never English. (e.g. Brookesia superciliaris is a dwarf chameleon with well developed superciliary spines (above the eyes); Guibemantis tasifotsy is a frog with white spots on its sides - tasifotsy is a Malagasy word for white spots, tasy meaning spots, and fotsy meaning white).
- A tribute to the location where the species is found (e.g. Phelsuma madagascariensis).
- A tribute to a notable researcher/person/organisation. If dedicated to a single person, these names always end in -i (e.g. Phelsuma gouldi was named in honour of Steven Jay Gould, noted evolutionary biologist and popular scientist).
Bad taxonomists, such as the infamous Raymond T. Hoser, tend to name species in tribute to mundane things, like their children, friends, and pets. This practice is strongly frowned upon but not technically against the rules. However, you are never allowed to name a species after yourself.
- When quoting a species name, especially in works that actually deal with taxonomy, usually the authors who originally described that species are listed alongside the species.
For instance: Brookesia stumpffi Boettger, 1894
- The date is not always necessary:
I could also just say Brookesia stumpffi Boettger.
- This rule applies in the same way to higher levels of classification (so for example: genus Brookesia Gray, 1865).
- If the species is no longer in the genus in which it was originally described (it has been moved from one to another), the name goes in brackets.
For example: Brookesia perarmata (Angel, 1933) was originally assigned to its own genus because it is so different from all other dwarf chameleons, but was later brought back into the genus Brookesia due to physical and genetic attributes.
When species are not easily distinguished based on physical or colour-based attributes, taxonomy gets a bit tricky. To get around this, there are several words that have been used for vague implications:
- the abbreviation ‘sp.’ refers to a species in a genus (e.g. Uroplatus sp.) that is either not yet described, or was not recognisable to the authors.
- the abbreviation ‘cf.’ refers to an individual or group of individuals that looked like a species, but whose identity is not 100% (e.g. Uroplatus cf. henkeli).
- the abbreviation ‘aff.’ refers to a species that is probably not yet described, but has certain aspects that suggest it is most closely related to a certain species (e.g. Uroplatus sp. aff. henkeli).
There are no set rules on how to use open nomenclature, so it’s a bit of a mess and is open to interpretations. Some people use ‘cf.’ and ‘aff.’ interchangeably. Suffice to say that, if it has one of these abbreviations in it, the taxonomy needs a bit of work.
Okay that is all for today’s lesson. I hope you learned some stuff. Sorry it was so long. Taxonomic nomenclature is complicated, but its intricacies are quite fun to wrap your head around.