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On the previous page we learned about the advantages of the (double) Latin/Greek names of species, now we'll have a look at the function of these names for the classification of the species.

For centuries, mankind felt a strong need to control and order the surrounding world. The overwhelming and uncontrollable nature that he lived in, should at least be named orderly. But such order is also indispensable for a better understanding of nature. So there were many scientists that engaged in this ordening and nomenclature, among them Aristotle.

The word taxonomy (taxo - make order, nomie - name) is often used for that classification, it is not exactly the same, but just for now let's pretend it is. You may think of a taxon as a larger or smaller box for the grouping of the species. R=The Swedish professor Carl Linnaeus introduced a ingenious system for the classification of nature, a system that we still use today. He adopted the binomial nomenclature ('double names') of Gaspard Bauhin, who used the 'two term naming' already in 1623 in one of his books on plants. Linnaeus used this system even stricter and not only on plants, but also on animals. With his system, Linnaeus thought he did justice to a divine influence and nature soon would be fully classified. But on to this day, only 10 percent of all living things have a name. More on Linnaeus at the end of this page.

You could see this as a box system, or more contemporary, a file system with folders on your laptop. Suppose we create a folder called genus1. To all species, belonging to that genus we give a double name, consisting of the Genus1 name and a unique name, like: 'Genus1 species1', 'Genus1 species2', etc. Then we store these double names in the Genus1 folder. Let's then create a folder called Genus2 for other species, that have characteristics like those of Genus1, but not enough match to put them in the Genus1 folder. Now to create a folder called Family1, and put both folders Genus1 and Genus2 in it. And thus we continue, untill we have a system with folders that contain folders that contain folders that contain... and so on. In classification, such a folder is called a taxon. The highest taxons in the system of Linnaeus were the kingdoms. These kingdoms were divided in tribes, the tribes in classes, the classes in orders, the orders in families, the families in genera and the genera in species. Those last two taxons determine the name of the plant or animal. The taxons, which are the folders of our previous example, have been adjusted many times. But more than that, in present time the taxons are seen as nodes andbranches of phylogenetic trees, that are still developing. With that fundamental change, classification came closer to the true nature of nature...

In 1996 a new classification of Carl Woese was accepted, which has six kingdoms. With this classification a new taxon was introduced, above the kingdom: the domain. There are three domains: 1 the bacteria, with the kingdom Bacteria or Eubacteria, 2 the archaea with the kingdom Prokaryota and third the Eukaryota with the kingdoms Protista, Fungi, Plantae en Animalia. You can read more in this article on Wikipedia.

Now let's put side by side four animals:

Domain Eukaryota Eukaryota Eukaryota Eukaryota
Kingdom animals animals animals animals
Tribe vertebrates vertebrates vertebrates arthropods
Class mammals mammals birds insects
Order Primates Carnivores Birds Hymenoptera
Family humanoids (Hominidae) cats (Felidae) thrushes bees (Apidae)
Genus Homo (human) Felix (cat) Turdus ('real' thrushes) Apis (bee)
Species sapiens (the knowing) domesticus (of the house) merula (blackbird) mellifera (honey making)

This table suggests the cat being closer to us, of course it's a mammal too. The blackbird is not, but it still is a vertebrate. The honey bee is further away from us, its only similarity being an animal. That seems alright, but in a way not very satisfying: the bee has a head and legs, unlike a worm, which would drop out at the same spot in the table. The present phylogeny often gives a clearer view on the relationships.

was the son of a Swedish doctor. He came to the Netherlands for a study in the city of Leiden. In those days plants still were an important source for medicines and Linnaeus had a passion for plants. In 1749 he wrote a book on medicinal plants, the Materia Medica. But he had already published his most important work before that: the Systema Naturae of 1735 ! In that first edition, (just a few folio sheets) he divided nature in three kingdoms: animals, plants and minerals. That last kingdom may seem strange, but is understandable from his perspective as a physician: medicines could originate from all three kingdoms.
At present time we know six kingdoms in taxonomy, as written above. All those changes would have surprised Linnaeus, who believed that all species were fixed and unchangeable. Darwins work certainly would have shocked him, especially the thought that no Almighty Creator was involved. But even in our 'enlightened age' that's still unacceptable for many humans...

In the first publication, Linnaeus divided the REGNUM ANIMALE (animal kingdom) in five tribes:

Beside those he created an extra category, the PARADOXA, placed under the amphibians. Here he dumped a number of animals that he didn't know were to place them: mythical beasts like the giant Hydra, the Unicorn (monoceros), the Satyr, the Dragon and the Phenyx, but also some real existing animals, like the giant tadpole of the Shrinking frog (Pseudis paradoxa) and the Pelican. The inclusion of these mythical creatures is not surprising, when you realise how little was known in that time about the animals of the far-off regions and the travellers that returned from there told fantastic stories. The VERMES group was a collection box, with several species thrown in: molluscs, jelly-fishes, squids and octopusses (among those a mythical animal: the Kraken). Linnaeus positioned humans at the animals, but right at the front, with the four-footers. He named humans of different continents as different species. Reptiles were placed within the amphibians; crustaceans, spiders and scorpions within the insects. Whales and dolphins stood between the fishes in this first publication. Some fresh water insects were also included: dragonflies, may flies, net-winged insects, mosquitoes, as species: Dytiscus, Gyrinus, Cimex, Notonecta and Nepa ( = Water Scorpion). Nepa was placed under Scorpio and Linnaeus thought it had four legs - the two front legs mistaken for pincers. Many people who see a Water Scorpion for the first time still make that mistake. Here is a weblink to "Systema Naturae" on Wikipedia. That article also contains a picture of the simple table for the division of the animal kingdom, that was printed in that publication.



Linnean Taxonomy on Wikipedia

Linnaeus and one sleepy guy (National Geographic)

Het Nederlandse Soortenregister (Dutch register of species), offers a tree structure


© G.H. Visser 16-08-2010
rev. 02-04-2022

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