User:Chuck Entz/About taxonomy

Introduction
Taxonomy is the science and practice of classification. This page will focus on the classification and naming of living things by scientists, mostly excluding [[virus]es.

How taxonomic names are created
A new name is created by publishing the name in a qualifying scientific work with enough information to distinguish it from other taxa.

Priority
In principle, a taxon keeps the first valid name it is given, and renaming a validly-named taxon isn't allowed. In practice, determining whether a name is the first and whether it is valid is very complicated.

Before the internet, it was very hard to check all the works where a name could be validly published. What's more, it can be hard to tell whether something one wants to describe belongs to the same taxon as the one that is described under a given name. On top of that, scientific advances have completely changed classification methods: two taxa that seemed quite different by comparing the size, shape, color and number of various structures often turn out to be very closely related when their DNA is compared.

The result is that a great many taxa have been described under multiple names, and it's not all that uncommon for an obscure name to turn up that predates the name that has been in almost universal use for that taxon for centuries. In such cases a decision is sometimes made to conserve a name that is otherwise invalid according to the rules

Ranks
The basic unit of taxonomy is the species. In the Linnaean system that is the current standard, a species name consists of a generic name and a specific epithet in the form of a binomial. Species can be further subdivided, in which case the name of the infraspecific taxon is written after the specific epithet to form a trinomial.

In the taxonomic codes, this arrangement leads to distinguishing between family-group, genus-group and species-group ranks. Any rank above the family group is not covered by the codes and is thus called a higher taxon

Taxonomic codes
These are the result of agreements between taxonomis