The Basics of Taxonomy
Part I in a VI part series
Problems in taxonomy
Prior to Linnaeus (as seen above), nomenclature was an unwieldy mess. There were plenty of folk taxonomies that had organically grown out of each culture’s unique linguistic connection to their local landscape. Many of these taxonomic systems had significant overlap with scientific taxonomies, particularly at the level of genus, but there were often discrepancies across the various systems (the Navajo, for example, lumped spiders in with birds and bats as flying beasts). With all those systems, each species invariably had multiple common names (see, for example, link), and a single common name might be applied to entirely unrelated species (as with the cedars).
A folk taxonomy is fine when you’re dealing with just your local plant and animal species (the average folk taxonomy typically includes about 600 plants – link; Carol Yoon’s book on taxonomy suggests that people can generally recall a list of about 600 things, whether they’re the names of bands, beetles, or books). But as naturalists scattered far and wide, collecting thousands and thousands of new specimens from thousands of new species (Alfred Russel Wallace alone sent over 100,000 specimens representing hundreds of species back to Europe from his travels abroad), it became increasingly difficult to keep track of all that biodiversity and to communicate clearly about a species across cultures and languages. Linnaeus arrived just at the time when a more rigorous, universal taxonomy was essential for the natural sciences to develop.
Yet more problems in taxonomy
As all these new species were discovered (or at least as naturalists became aware of the diversity on different continents), they were described and named by hundreds of amateur naturalists. There were no real conventions at the time for coming up with scientific names, and the names grew and grew in length to the point of absurdity. The scientific name for wild briar rose, for example, was Rosa sylvestris alba cum rubore, folio glabro.
A simpler solution
Linnaeus did away with all that fluffy baggage, and his system ultimately settled on a simpler binomial system governed by a strict set of rules (the wild briar rose under his system would become the simpler Rosa canina). Linnaeus’ system could be applied consistently to all living things, and ensured that each species had one and only one scientific name. So Rosa canina was Rosa canina to Indian, French, American, and Chinese botanists. His system ultimately won the day and a (heavily) modified version is still in use today.
Finding order
As naturalists attempted to classify new species, the process of classification began to draw into relief the morphological and physiological relationships between taxa, which ultimately alluded to the underlying evolutionary relationships between species. For Linnaeus, Lamarck, Darwin, Wallace, and others, these relationships revealed by classification clarified that there was indeed an order to the natural world, pushing the back the fog of mysticism to the edges of the woods. Though Linnaeus didn’t believe in troglodytes, demons, satyrs, or pygmies, he included them in his classification system to illustrate that all things belonged to the natural order of things (Troglodytes bontii, Lucifera aldrovandi, Satyrus tulpii, and Pygmaeus edwardii).
Taxonomic Rankings
Linnaeus’ binomials ultimately got folded into a larger scheme that included hierarchical ranks above the genus level. The simplest version you’ll see today looks something like the table below. I included a fun mnemonic that a student of mine came up with to remember the order. Feel free to send me your favorite.
Rank | Mnemonic | Mnemonic | Your Mnemonic |
---|---|---|---|
Kingdom | Keep | Keep | ? |
Phylum | Pond | Posting | ? |
Class | Clean | Crap | ? |
Order | Or | Online | ? |
Family | Froggy | For | ? |
Genus | Gets | Gods | ? |
Species | Sick | Sake | ? |
ITIS.gov, which keeps an updated database of currently accepted taxonomic names, uses 19 different ranks from kingdom to subspecies (see the gray squirrel’s entry for an example). Note also that botanists use Division rather than Phylum and most modern taxonomists recognize Domain as the top level above Kingdom.
Okay, that’s it for now. More in a couple of days on how things get named and what they get named for. And then onto translations.
Resources
- An Etymology of Vermont Vertebrates by yours truly
- Borror’s Dictionary of Word Roots and Combining Forms (pdf)
- Yoon’s Naming Nature
- Helm Dictionary of Scientific Bird Names (free online)
- A good overview of the process for naming a new species (link)