Synonyms

Synonyms in taxonomy are the different names that have been applied to a given species, genus, or other taxonomic categories. These are synonyms, which tend to arise when multiple new names are created for the same taxon, often through independent discoveries or adiaphorous reclassifications / revisions in taxonomic understanding. Taxonomic synonyms serve to document the history of scientific understanding and classification through time, but also provide a conceptual basis for dealing with redundancy in naming.

In zoology and botany, many species have been independently characterized by different researchers in different geographical areas or at different times — also known as the taxonomic synonyms. Dissolution of synonyms can arise from a revision in concept of an organism's morphology, its behavior, genetic data or relations with more basal taxa. Synonymous treatment guarantees that each taxon has a single, generally accepted name, as required by the international codes of nomenclature (International Code of Zoological Nomenclature [ICZN] and International Code of Nomenclature for algae fungi and plants [ICN]).

The Usage of Synonyms as General in Taxonomy

Taxonomic synonyms: List by subject This entry contributed to the ISI by UnderstandingScience. There are three primary scenarios that give rise to synonyms:

Independent Discoveries: More than one researcher may discover and name a species independently without knowledge of what the other has done. This used to happen often when communication was poor and published work hardly circulating. For example, if two scientists in separate countries described some particular butterfly and named it differently — each unaware of the others work — those names would later be deemed synonyms as long as both species refer to the same species.

Taxonomic changes: Science is ever-evolving; things change. Recent studies using sequencing technology, molecular biology advances or morphological analysis have distinguished and shown the synonymy of taxa that were seemingly distinct. Under such circumstances only one name is kept (usually the oldest validly published name) while all others are treated as synonyms.

Change in Classification Systems: Taxonomy is not a static field, and there are times that species will be shifted between genera, or reclassified altogether due to better information about how these groups are related evolutionarily. This is referred to as synonymy, where other names have been used for the same species and are documented—this allows earlier literature to be understood through new classification.

For scientific writing and research, synonyms follow the accepted name of the organism to avoid confusion or help identify historical records or prior research. When recording synonyms, the purpose is to provide an unambiguous statement of all names which have been applied to a taxon, generally in chronological order or according to scientific priority.

Synonyms, Zoological and the ICZN

The International Code of Zoological Nomenclature (ICZN) governs the creation, usage and resolution of synonyms in zoology. One of the purposes of the ICZN is to promote uniformity in naming practices within the field, and to prevent conflicts that may arise from synonyms. Zoological synonyms are of several types:

Objective Synonyms: These arise when two or more names have been given to the same taxon based on exactly the same type specimens or identical descriptions. For instance, if two scientists describe the same specimen of a species but give it different names, those names are known as objective synonyms.

Subjective Synonyms — These are cases where different type specimens were involved but the organisms involved later found to belong to the same taxon and become synonyms on the basis of scientific opinion (consensus) or re-analysis. For example, it could occur when two different specimens are originally thought to be species A and B but more intensive research reveals that they actually belonged to the same species.

To resolve such cases, the ICZN has defined a principle of nomenclature, called the Principle of Priority that determines which name is valid when different synonyms exist. The principle states that the earliest name which is published in accordance to all relevant elements of the Code shall be the valid name, and later names are synonyms. It encourages stability and reduces confusion by giving precedence to the name that is first validly published for a taxon.

Zoological Examples

We can give a few examples of zoological synonyms based on some commonly encountered taxa as follows:

The jaguar (Panthera onca) has two scientific names to its credit since it was first scientifically described. Several synonyms were used by other researchers, including Felis onca and Leopardus onca; all these names are now taxonomic synonyms under the valid name Panthera onca.

Bison bison (American Bison): early European explorers and naturalists independently named the American bison, which is why the species has different names. As synonyms under the accepted name Bison bison, names like Bos bison and Bison americanus have dropped out of use.

These are examples of what happens to all the synonyms that accumulate over time, as researchers rethink taxonomic classification. Synonyms are a record of past names and they assist in reducing confusion in the scientific literature by recording all available names for a species.

Significance of Synonyms in Zoology

In zoology, synonyms have some important functions. First they offer historical context, a way of honoring previous taxonomic work and recording shifts in scientific thought. This not only avoids confusion and a scenario where research lacks context that results in inaccurate interpretations but also creates the possibility for researchers to cross-reference names that appear across various geographical locations and society contexts as synonyms. For instance, if an ancient paper mentions an animal with a synonym, researchers can use the contemporary accepted name to track it down due to systematic cataloging of synonyms.

Finally, synonyms are used to support the study of biodiversity by showing how taxonomic interpretations change through time. Synonym lists also help researchers identify specimens, particularly those in museum collections or historical records. For example, a researcher can query for all known synonyms of a species to get an aggregated view of the distribution and traits of that taxon if it has been described under several names.

2.0 Synonymy in Other Taxonomic Areas

This is not just a problem in the field of zoology; rather, in botany as well as other areas of taxonomy, synonymy has an equally important place. In the field of botany, synonyms are regulated under the International Code of Nomenclature for algae, fungi, and plants (ICN). On the model of zoological synonymy, under the ICN synonyms must be shown to have been published earlier than any validly published name. But in botany, synonyms are divided further into the following categories:

Homotypic synonyms: Same name as the type specimen, equals to objective synonyms -- zoology Both of these synonyms come up when one specimen has been described by different names in botany.

Heterotypic Use: Names based on different types; the same as subjective synonyms in zoology In these latter instances, different specimens initially considered representing different species were combined into an overarching taxon.

Synonyms are a necessary evil in botany, just as they are in zoology: to avoid such confusion future generations of scientists may have trouble researching the same species.

Synonyms as Taxonomy and Their Importance As Modern Synonyms

Identifying and classifying organisms have become more refined with developments in genetics, molecular biology, and bioinformatics—leading to often widespread revision and reclassification while creating new synonyms. Such as, DNA sequencing can show us genetic similarities and result in organisms that were once classified as different species getting reclassified. Thus, modern taxonomical works often return to old convents and produce novel synonyms but also consolidate a clear taxonomical picture.

Organization of synonyms is specially important in taxonomically completed digitized databases, for example those mentioned above, that are currently frequently used in variety identification (ITIS, Integrated Taxonomic Information System [14], GBIF, Global Biodiversity Information Facility [15]). They list synonyms that help researchers and the public find data on species irrespective of the name used in different publications.