PhyloCode
PhyloCode
Main page

PhyloCode

logo
Community Hub0 subscribers

PhyloCode

logo
Community Hub0 subscribers
What are your thoughts?
Be the first to start a discussion here.
Be the first to start a discussion here.
PhyloCode

The International Code of Phylogenetic Nomenclature, known as the PhyloCode for short, is a formal set of rules governing phylogenetic nomenclature. Its current version is specifically designed to regulate the naming of clades, leaving the governance of species names up to the rank-based nomenclature codes (ICN, ICNCP, ICNP, ICZN, ICVCN).

The PhyloCode is associated with the International Society for Phylogenetic Nomenclature (ISPN). The companion volume, Phylonyms, establishes 300 taxon names under PhyloCode, serving as examples for those unfamiliar with the code. RegNum is an associated online database for registered clade names.

The PhyloCode regulates phylogenetic nomenclature by providing rules for deciding which associations of names and definitions are considered established, which of those will be considered homonyms or synonyms, and which one of a set of synonyms or homonyms will be considered accepted (generally the one registered first; see below). The PhyloCode only governs the naming of clades, not of paraphyletic or polyphyletic groups, and only allows the use of specimens, species, and apomorphies as specifiers (anchors).

Unlike rank-based nomenclatural codes (ICN, ICZN, ICNB), the PhyloCode does not require the use of ranks, although it does optionally allow their use. The rank-based codes define taxa using a rank (such as genus, family, etc.) and, in many cases, a type specimen or type subtaxon. The exact content of a taxon, other than the type, is not specified by the rank-based codes.

In contrast, under phylogenetic nomenclature, the content of taxa are delimited using a definition that is based on phylogeny (i.e., ancestry and descent) and uses specifiers (e.g., species, specimens, apomorphies) to indicate actual organisms. The formula of the definition indicates an ancestor. The defined taxon, then, is that ancestor and all of its descendants. Thus, the content of a phylogenetically defined taxon relies on a phylogenetic hypothesis.

The following are examples of types of phylogenetic definition (capital letters indicate specifiers):

Other types of definition are possible as well, taking into account not only organisms' phylogenetic relations and apomorphies but also whether or not related organisms are extant.

The following table gives examples of phylogenetic definitions of clades that also have ranks in traditional nomenclature. When all the specifiers in a node-based definition are extant specimens or species, as in the following definition of Mammalia, a crown group is defined. (The traditional definition of Mammalia is less restrictive, including some fossil groups outside of the crown group.)

See all
User Avatar
No comments yet.