Wikipedia:WikiProject Protista/Article guidelines

WikiProject Protista

Main pageTalkArticle guidelinesPopular pagesNew articlesRequests

Below is a growing list of guidelines and recommendations for when dealing with taxonomic articles.

Article titles

When choosing a name for the article on a taxon, the informal (vernacular) name that is most commonly used is preferred. This follows the general guidelines for article titles of Wikipedia. In absence of a popular informal name, the most common formal (scientific) name is used. If the taxon is monotypic, the formal name with the lowest rank is preferred; this is consistent with the naming conventions for monotypic flora and fauna. If there are multiple formal names (synonyms) of relatively similar popularity for the same rank, the least controversial formal name is used (i.e., with highest taxonomic priority, such as by date of publication or by date of first accurate circumscription).

Example: Apusomonad (vernacular) > Apusomonadidae (family) > Apusomonadida (monotypic order).

Code of nomenclature

The two existing codes that regulate eukaryotic nomenclature (ICZN for zoology, ICNafp for botany) often come into conflict with protists. Historically, the ICZN was the authority for all protozoa, while the ICNafp regulated algae and fungus-like protists such as slime molds, but these too are frequently treated as protozoa, and some protozoa are occasionally treated as algae. Because these groups are evolutionarily intertwined, there is no solid barrier which firmly separates zoology from botany in the realm of protists. Instead, protistologists tend to implement their own 'code', where the authority is written the following way: Taxon Author, Year. For example, a new combination (i.e. a species transferred to a new genus) would be written as:

Urceolus cyclostomus (Stein, 1878) Mereschkowsky, 1877

basionym: Phialonema cyclostomum Stein, 1878

This differs from both the botanical code, which omits the year of publication, and the zoological code, which omits the authors of new combinations in favor of retaining only the author of the original species name, which becomes later a basionym. For example:

Aprostocetus hagenowii (Ratzeburg, 1852) (zoological name)

basionym: Entedon hagenowii Ratzeburg, 1852

Dinema polybulbon (Sw.) Lindl. (botanical name)

basionym: Epidendrum polybulbon Sw.

Conflicting classification systems

The Tree of Life project maintains a unified system of classification through the automated taxobox system. However, whereas animal, fungal, plant and prokaryotic taxonomists work under relatively coherent classification systems, there are two mutually exclusive approaches to protist classification.

• The traditional or ranked approach maintains a hierarchy that does not necessarily follow natural evolutionary groups (clades), and instead also employs some artificial (paraphyletic or polyphyletic) groups to sort protists. This system, developed primarily by evolutionary biologist Thomas Cavalier-Smith (1942–2021), proposes five kingdoms of eukaryotes: Plantae, Animalia, Fungi, "Protozoa" and "Chromista" (both non-clades). It provides a detailed categorization for most eukaryotes through ranks equivalent to those used for other organisms (kingdoms, phyla, classes, orders...), but many of the taxa are not clades. This is contrary to the classification of other organisms, as evolutionary relatedness is the basis of categorizing animals, fungi, plants, and even prokaryotes. In addition, this scheme has been unstable throughout its lifespan, with many scientific names being repurposed for different circumscriptions after hypotheses were rejected (e.g., Archezoa, Opalozoa, Corticata) and others changing spelling altogether as a result of being moved into a different rank. Consequently, it has very limited use in the larger scientific community.

• The cladistic or phylogenetic approach embraces the abandonment of traditional concepts (e.g., protozoa, algae) brought by molecular phylogenetics, and prioritizes a hierarchy based on clades. It was initiated by authors such as David J. Patterson and developed collectively by the International Society of Protistologists (ISOP) through periodical publications that represent the consensus of the scientific community. This system uses clade names without formal rank designations, to avoid issues caused by ranks (such as name changes); as such, it remains stable across time. Instead of artificially separated kingdoms, this system recognizes monophyletic supergroups that contain both the "higher" eukaryotes (animals, fungi, plants) and the protists from which they evolved. Still, some artificial taxa are maintained in this system because there is no cladistic alternative yet (e.g., "Retortamonadida", "Monothalamea").

This WikiProject and its parent Tree of Life project prioritize the cladistic approach, as it represents the scientific consensus and is compatible with the automated taxobox system. For consistency with the ranked classifications of other organisms, ranks are still used whenever possible.