Synonym (taxonomy)

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The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently.

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Unlike synonyms in other contexts, in taxonomy a synonym is not interchangeable with the name of which it is a synonym. In taxonomy, synonyms are not equals, but have a different status. For any taxon with a particular circumscription, position, and rank, only one scientific name is considered to be the correct one at any given time (this correct name is to be determined by applying the relevant code of nomenclature). A synonym cannot exist in isolation: it is always an alternative to a different scientific name. Given that the correct name of a taxon depends on the taxonomic viewpoint used (resulting in a particular circumscription, position and rank) a name that is one taxonomist's synonym may be another taxonomist's correct name (and vice versa).

Synonyms may arise whenever the same taxon is described and named more than once, independently. They may also arise when existing taxa are changed, as when two taxa are joined to become one, a species is moved to a different genus, a variety is moved to a different species, etc. Synonyms also come about when the codes of nomenclature change, so that older names are no longer acceptable; for example, Erica herbacea L. has been rejected in favour of Erica carnea L. and is thus its synonym. [3]

General usage

To the general user of scientific names, in fields such as agriculture, horticulture, ecology, general science, etc., a synonym is a name that was previously used as the correct scientific name (in handbooks and similar sources) but which has been displaced by another scientific name, which is now regarded as correct. Thus Oxford Dictionaries Online defines the term as "a taxonomic name which has the same application as another, especially one which has been superseded and is no longer valid". [4] In handbooks and general texts, it is useful to have synonyms mentioned as such after the current scientific name, so as to avoid confusion. For example, if the much-advertised name change should go through and the scientific name of the fruit fly were changed to Sophophora melanogaster, it would be very helpful if any mention of this name was accompanied by "(syn. Drosophila melanogaster)". Synonyms used in this way may not always meet the strict definitions of the term "synonym" in the formal rules of nomenclature which govern scientific names (see below).

Changes of scientific name have two causes: they may be taxonomic or nomenclatural. A name change may be caused by changes in the circumscription, position or rank of a taxon, representing a change in taxonomic, scientific insight (as would be the case for the fruit fly, mentioned above). A name change may be due to purely nomenclatural reasons, that is, based on the rules of nomenclature;[ citation needed ] as for example when an older name is (re)discovered which has priority over the current name. Speaking in general, name changes for nomenclatural reasons have become less frequent over time as the rules of nomenclature allow for names to be conserved, so as to promote stability of scientific names.

Zoology

In zoological nomenclature, codified in the International Code of Zoological Nomenclature , synonyms are different scientific names of the same taxonomic rank that pertain to that same taxon. For example, a particular species could, over time, have had two or more species-rank names published for it, while the same is applicable at higher ranks such as genera, families, orders, etc. In each case, the earliest published name is called the senior synonym, while the later name is the junior synonym. In the case where two names for the same taxon have been published simultaneously, the valid name is selected accorded to the principle of the first reviser such that, for example, of the names Strix scandiaca and Strix noctua (Aves), both published by Linnaeus in the same work at the same date for the taxon now determined to be the snowy owl, the epithet scandiaca has been selected as the valid name, with noctua becoming the junior synonym. (Incidentally, this species has since been reclassified and currently resides in the genus Bubo , as Bubo scandiacus [5] ).

One basic principle of zoological nomenclature is that the earliest correctly published (and thus available) name, the senior synonym, by default takes precedence in naming rights and therefore, unless other restrictions interfere, must be used for the taxon. However, junior synonyms are still important to document, because if the earliest name cannot be used (for example, because the same spelling had previously been used for a name established for another taxon), then the next available junior synonym must be used for the taxon. For other purposes, if a researcher is interested in consulting or compiling all currently known information regarding a taxon, some of this (including species descriptions, distribution, ecology and more) may well have been published under names now regarded as outdated (i.e., synonyms) and so it is again useful to know a list of historic synonyms which may have been used for a given current (valid) taxon name.

Objective synonyms refer to taxa with the same type and same rank (more or less the same taxon, although circumscription may vary, even widely). This may be species-group taxa of the same rank with the same type specimen, genus-group taxa of the same rank with the same type species or if their type species are themselves objective synonyms, of family-group taxa with the same type genus, etc. [6]

In the case of subjective synonyms, there is no such shared type, so the synonymy is open to taxonomic judgement, [7] meaning that there is room for debate: one researcher might consider the two (or more) types to refer to one and the same taxon, another might consider them to belong to different taxa. For example, John Edward Gray published the name Antilocapra anteflexa in 1855 for a species of pronghorn, based on a pair of horns. However, it is now commonly accepted that his specimen was an unusual individual of the species Antilocapra americana published by George Ord in 1815. Ord's name thus takes precedence, with Antilocapra anteflexa being a junior subjective synonym.

Objective synonyms are common at the rank of genera, because for various reasons two genera may contain the same type species; these are objective synonyms. [8] In many cases researchers established new generic names because they thought this was necessary or did not know that others had previously established another genus for the same group of species. An example is the genus Pomatia Beck, 1837, [9] which was established for a group of terrestrial snails containing as its type species the Burgundy or Roman snail Helix pomatia —since Helix pomatia was already the type species for the genus Helix Linnaeus, 1758, the genus Pomatia was an objective synonym (and useless). On the same occasion, Helix is also a synonym of Pomatia, but it is older and so it has precedence.

At the species level, subjective synonyms are common because of an unexpectedly large range of variation in a species, or simple ignorance about an earlier description, may lead a biologist to describe a newly discovered specimen as a new species. A common reason for objective synonyms at this level is the creation of a replacement name.

A junior synonym can be given precedence over a senior synonym, [10] primarily when the senior name has not been used since 1899, and the junior name is in common use. The older name may be declared to be a nomen oblitum , and the junior name declared a nomen protectum . This rule exists primarily to prevent the confusion that would result if a well-known name, with a large accompanying body of literature, were to be replaced by a completely unfamiliar name. An example is the European land snail Petasina edentula (Draparnaud, 1805). In 2002, researchers found that an older name Helix depilata Draparnaud, 1801 referred to the same species, but this name had never been used after 1899 and was fixed as a nomen oblitum under this rule by Falkner et al. 2002. [11]

Such a reversal of precedence is also possible if the senior synonym was established after 1900, but only if the International Commission on Zoological Nomenclature (ICZN) approves an application. (Here the C in ICZN stands for Commission, not Code as it does at the beginning of § Zoology. The two are related, with only one word difference between their names.) For example, the scientific name of the red imported fire ant, Solenopsis invicta was published by Buren in 1972, who did not know that this species was first named Solenopsis saevissima wagneri by Santschi in 1916; as there were thousands of publications using the name invicta before anyone discovered the synonymy, the ICZN, in 2001, ruled that invicta would be given precedence over wagneri.

To qualify as a synonym in zoology, a name must be properly published in accordance with the rules. Manuscript names and names that were mentioned without any description ( nomina nuda ) are not considered as synonyms in zoological nomenclature.

Botany

In botanical nomenclature, a synonym is a name that is not correct for the circumscription, position, and rank of the taxon as considered in the particular botanical publication. It is always "a synonym of the correct scientific name", but which name is correct depends on the taxonomic opinion of the author. In botany the various kinds of synonyms are:

In botany, although a synonym must be a formally accepted scientific name (a validly published name): a listing of "synonyms", a "synonymy", often contains designations that for some reason did not make it as a formal name, such as manuscript names, or even misidentifications (although it is now the usual practice to list misidentifications separately [12] ).

Comparison between zoology and botany

Although the basic principles are fairly similar, the treatment of synonyms in botanical nomenclature differs in detail and terminology from zoological nomenclature, where the correct name is included among synonyms, although as first among equals it is the "senior synonym":

Synonym lists

Scientific papers may include lists of taxa, synonymizing existing taxa and (in some cases) listing references to them.

The status of a synonym may be indicated by symbols, as for instance in a system proposed for use in paleontology by Rudolf Richter. In that system a v before the year would indicate that the authors have inspected the original material; a . that they take on the responsibility for the act of synonymizing the taxa. [13]

Other usage

The traditional concept of synonymy is often expanded in taxonomic literature to include pro parte (or "for part") synonyms. These are caused by splits and circumscriptional changes. They are usually indicated by the abbreviation "p.p." [14] For example:

See also

Related Research Articles

Genus is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus.

<span class="mw-page-title-main">Binomial nomenclature</span> System of identifying species of organisms using a two-part name

In taxonomy, binomial nomenclature, also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages. Such a name is called a binomial name, a binomen, binominal name, or a scientific name; more informally it is also historically called a Latin name. In the ICZN, the system is also called binominal nomenclature, "binomi'N'al" with an "N" before the "al", which is not a typographic error, meaning "two-name naming system".

<span class="mw-page-title-main">International Code of Zoological Nomenclature</span> Code of scientific nomenclature for animals

The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the International Commission on Zoological Nomenclature. The rules principally regulate:

<span class="mw-page-title-main">Taxon</span> Grouping of biological populations

In biology, a taxon is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion, especially in the context of rank-based ("Linnaean") nomenclature. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping.

<span class="mw-page-title-main">Holotype</span> Example of an organism used to describe its species

A holotype is a single physical example of an organism used when the species was formally described. It is either the single such physical example or one of several examples, but explicitly designated as the holotype. Under the International Code of Zoological Nomenclature (ICZN), a holotype is one of several kinds of name-bearing types. In the International Code of Nomenclature for algae, fungi, and plants (ICN) and ICZN, the definitions of types are similar in intent but not identical in terminology or underlying concept.

<span class="mw-page-title-main">Type species</span> Term used in biological nomenclature

In zoological nomenclature, a type species is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen. A similar concept is used for suprageneric groups and called a type genus.

<span class="mw-page-title-main">Type (biology)</span> Specimen(s) to which a scientific name is formally attached

In biology, a type is a particular specimen of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to anchor or centralizes the defining features of that particular taxon. In older usage, a type was a taxon rather than a specimen.

In the scientific name of organisms, basionym or basyonym means the original name on which a new name is based; the author citation of the new name should include the authors of the basionym in parentheses. The term "basionym" is used in both botany and zoology. In zoology, alternate terms such as original combination or protonym are sometimes used instead. Bacteriology uses a similar term, basonym, spelled without an i.

<span class="mw-page-title-main">Botanical name</span> Scientific name for a plant, alga or fungus

A botanical name is a formal scientific name conforming to the International Code of Nomenclature for algae, fungi, and plants (ICN) and, if it concerns a plant cultigen, the additional cultivar or Group epithets must conform to the International Code of Nomenclature for Cultivated Plants (ICNCP). The code of nomenclature covers "all organisms traditionally treated as algae, fungi, or plants, whether fossil or non-fossil, including blue-green algae (Cyanobacteria), chytrids, oomycetes, slime moulds and photosynthetic protists with their taxonomically related non-photosynthetic groups ."

Botanical nomenclature is the formal, scientific naming of plants. It is related to, but distinct from taxonomy. Plant taxonomy is concerned with grouping and classifying plants; botanical nomenclature then provides names for the results of this process. The starting point for modern botanical nomenclature is Linnaeus' Species Plantarum of 1753. Botanical nomenclature is governed by the International Code of Nomenclature for algae, fungi, and plants (ICN), which replaces the International Code of Botanical Nomenclature (ICBN). Fossil plants are also covered by the code of nomenclature.

Nomenclature codes or codes of nomenclature are the various rulebooks that govern the naming of living organisms. Standardizing the scientific names of biological organisms allows researchers to discuss findings.

In botany, the correct name according to the International Code of Nomenclature for algae, fungi, and plants (ICN) is the one and only botanical name that is to be used for a particular taxon, when that taxon has a particular circumscription, position and rank. Determining whether a name is correct is a complex procedure. The name must be validly published, a process which is defined in no less than 16 Articles of the ICN. It must also be "legitimate", which imposes some further requirements. If there are two or more legitimate names for the same taxon, then the correct name is the one which has priority, i.e. it was published earliest, although names may be conserved if they have been very widely used. Validly published names other than the correct name are called synonyms. Since taxonomists may disagree as to the circumscription, position or rank of a taxon, there can be more than one correct name for a particular plant. These may also be called synonyms.

In zoological nomenclature, author citation is the process in which a person is credited with the creation of the scientific name of a previously unnamed taxon. When citing the author of the scientific name, one must fulfill the formal requirements listed under the International Code of Zoological Nomenclature. According to Article 51.1 of the Code, "The name of the author does not form part of the name of a taxon and its citation is optional, although customary and often advisable." However, recommendation 51A suggests, "The original author and date of a name should be cited at least once in each work dealing with the taxon denoted by that name. This is especially important and has a unique character between homonyms and in identifying species-group names which are not in their native combinations". For the sake of information retrieval, the author citation and year appended to the scientific name, e.g. genus-species-author-year, genus-author-year, family-author-year, etc., is often considered a "de-facto" unique identifier, although this usage may often be imperfect.

In botanical nomenclature, author citation is the way of citing the person or group of people who validly published a botanical name, i.e. who first published the name while fulfilling the formal requirements as specified by the International Code of Nomenclature for algae, fungi, and plants (ICN). In cases where a species is no longer in its original generic placement, both the authority for the original genus placement and that for the new combination are given.

In zoological nomenclature, the valid name of a taxon is the correct scientific name for that taxon. The valid name must be used for that taxon, regardless of any other name that may currently be used for that taxon, or may previously have been used. A name can only be valid when it is an available name under the International Code of Zoological Nomenclature (ICZN); if a name is unavailable, then it cannot be considered either valid or invalid.

<span class="mw-page-title-main">Conserved name</span> Conserved name (a protected scientific name)

A conserved name or nomen conservandum is a scientific name that has specific nomenclatural protection. That is, the name is retained, even though it violates one or more rules which would otherwise prevent it from being legitimate. Nomen conservandum is a Latin term, meaning "a name to be conserved". The terms are often used interchangeably, such as by the International Code of Nomenclature for Algae, Fungi, and Plants (ICN), while the International Code of Zoological Nomenclature favours the term "conserved name".

In zoological nomenclature, an available name is a scientific name for a taxon of animals that has been published after 1757 and conforming to all the mandatory provisions of the International Code of Zoological Nomenclature for the establishment of a zoological name.

<span class="mw-page-title-main">Taxonomic rank</span> Level in a taxonomic hierarchy

In biology, taxonomic rank is the relative level of a group of organisms in an ancestral or hereditary hierarchy. A common system of biological classification (taxonomy) consists of species, genus, family, order, class, phylum, kingdom, and domain. While older approaches to taxonomic classification were phenomenological, forming groups on the basis of similarities in appearance, organic structure and behaviour, methods based on genetic analysis have opened the road to cladistics.

<i>Nomen illegitimum</i> Latin term meaning "illegitimate name", used mainly in botany.

Nomen illegitimum is a technical term, used mainly in botany. It is usually abbreviated as nom. illeg. Although the International Code of Nomenclature for algae, fungi, and plants uses Latin terms for other kinds of name, the glossary defines the English phrase "illegitimate name" rather than the Latin equivalent. However, the Latin abbreviation is widely used by botanists and mycologists.

<span class="mw-page-title-main">Glossary of scientific naming</span> List of terms and symbols used in scientific names for organisms, and in describing the names.

This is a list of terms and symbols used in scientific names for organisms, and in describing the names. For proper parts of the names themselves, see List of Latin and Greek words commonly used in systematic names. Note that many of the abbreviations are used with or without a stop.

References

  1. ICN, "Glossary", entry for "synonym"
  2. ICZN Code
  3. ICN, Appendix IV
  4. "synonym". Oxford Dictionaries Online. Archived from the original on June 3, 2011. Retrieved 2011-11-28.
  5. BirdLife International (2017). " Bubo scandiacus". IUCN Red List of Threatened Species . 2017: e.T22689055A119342767. Retrieved 10 December 2017.
  6. ICZN, Art. 61.3
  7. ICZN, Art. 61.3.1
  8. ICZN, Art. 61.3.3
  9. p. 43 in Beck, H. 1837. Index molluscorum præsentis ævi musei principis augustissimi Christiani Frederici. – pp. 1–100 [1837], 101–124 [1838]. Hafniæ.
  10. ICZN, Art. 23.9 "reversal of precedence"
  11. Falkner, G., Ripken, T. E. J. & Falkner, M. 2002. Mollusques continentaux de France. Liste de référence annotée et bibliographie. – pp. [1–2], 1–350, [1–3]. Paris.
  12. ICN, Recommendation 50D
  13. Matthews, S. C. (1973), "Notes on open nomenclature and synonymy lists" (PDF), Palaeontology , 16: 713–719, archived from the original (PDF) on 2018-12-31, retrieved 2017-12-03.
  14. Berendsohn, W. G. (1995), "The concept of "potential taxa" in databases" (PDF), Taxon, 44 (2): 207–212, doi:10.2307/1222443, JSTOR   1222443, archived (PDF) from the original on 2016-09-10, retrieved 2009-03-21.

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