Posts Tagged ‘binomial nomenclature’

Carolus Linnaeus, that is. Strictly speaking, that should be Happy Belated Birthday, as his birthdate is May 23, 1707. The 300th anniversary of his birth was celebrated in 2007. What an amazing man. Darwin gets lots of credit for the whole Origin of Species thing, even though Alfred Russel Wallace had come to similar conclusions contemporaneously. I think I prefer Linnaeus as a hero. He brought order to the study of natural science.

Taxonomy, or systematics, is the science of classifying organisms. The system that was developed by the great Swedish botanist Linnaeus is still used today. It is a hierarchical system that ranks every organism, both plant and animal and even the neither here nor theres, in a series of categories. You may be familiar with King Phillip Comes Over For Good Soup, or some similar mnemonic. The phrase reminds schoolchildren and more than a few adults of the hierarchy: Kingdom, phylum, class, order, family, genus and species.

Somehow, I missed this in school and came to it late in life when I developed an interest in birds. Birds belong to the kingdom Animalia; the phylum Chordata (animals with vertebrae, or a backbone); and class Aves (this class refers exclusively to birds). There are about 2 dozen orders of birds. Names of orders end in “iformes”. The largest order is Passeriformes, the perching birds, which include more than half of the world’s approximately 10,000 species. Other orders are referred to as non-passerines. Examples of other orders are Piciformes (woodpeckers); Columbiformes (pigeons and doves); and Anseriformes (ducks and geese).

Each order is divided into families. There are many families in Passeriformes. Examples are Corvidae (crows and jays) and Turdidae (thrushes). Bird guides are generally set up in a standard layout of orders and families. The layout reflects the evolutionary age of the orders and species. The orders thought to have evolved first are at the beginning of guides. The more recently-evolved birds, the passerines, are presented after all the other orders.

Each family is divided into genera, which include very similar species. Each species has a latinized name made up of the genus combined with a specific name to distinguish it from other members of its genus. A shared genus name indicates that two species are closely related. Scientific names are traditionally italicized. Because the Linnean system features a two-part scientific name it is commonly referred to as binomial nomenclature. Here is how the American Robin (Turdus migratorius), above, photographed recently in my garden, would be classified:

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Turdidae
Genus: Turdus
Species: migratorius

The Canada geese (Branta canadensis) that I photographed last winter would be classified as follows:

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Genus: Branta
Species: canadensis

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