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Binomial nomenclature

binomial nomenclature definition

Definition of binomial nomenclature

Binomial Nomenclature Definition

Binomial nomenclature is a binomial system of naming a species. A binomial name is comprised of two parts, i.e. the generic name (genus name) and the specific name (or specific epithet, in botanical nomenclature). It is often in a Latinized form. Synonyms: binominal nomenclature; binary nomenclature; two-term naming system.

What is Binomial Nomenclature in Biology

In biology, binomial nomenclature is essential to integrate the naming system across life sciences and therefore assign one particular unique name identifier for a particular species across different languages. Binomial nomenclature is used especially by taxonomists in naming or identifying a species of a particular organism. It is used to come up with a scientific name for a species that is often based in Greek or Latin language. Although Latin is now a defunct language, the naming of organisms is still being used in this language.

The scientific name of a species that is set by binomial nomenclature entails two parts: (1) generic name (genus name) and (2) specific name (or specific epithet). In this regard, the scientific name is also referred to as the binomial name (or simply, binomial or binomen). The generic name is the taxonomic genus. A genus is a rank in the classification system that is generally below the family and above the species level. It is comprised of species with common attributes. These attributes may be based on structural similarities or on phylogeny. The second part of the binomial name is the specific name. In botanical nomenclature, the second part is particularly referred to as the “specific epithet”. The second name (the specific name or the specific epithet) sets a particular species apart from the rest of the species within the genus.

Who Came up with Binomial Nomenclature

Carl Linnaeus, the father of modern taxonomy and methods of classification, was the one who formalized the binomial nomenclature as the modern system of naming organisms. He designed the system so as to differentiate species from one to the other. In his book, Systema Naturae, he described and classified thousands of species of plants and animals. Soon, he had to track his classifications and to do that he came up with a concise naming system leading to the several binomial labels of species that he consistently used in his work, and eventually were applied and popularized in the scientific community. Although Carl Linnaeus was credited for the modern two-term naming system, his work was largely influenced by that of Gaspard Bauhin, together with his brother, Johann Bauhin. The Bauhin brothers were using the binomial nomenclature almost 200 years earlier. Many of the generic names introduced by them were adopted by Linnaeus. (Ref. 1)

Carl Linnaeus Systema Naturae binomial nomenclature
Carl Linnaeus’s, book “Systema Naturæ” (1758, 10th ed.)

How does Binomial Nomenclature Work

Binomial nomenclature proved to be essential in the scientific community. Through this system, taxonomists from all around the world can identify a species in unison. Unlike the common names that can differ from one language to another, a scientific name proved to be more consistent. Not only will scientists and taxonomists evade inconsistency issues but they can also have an idea of the genus through which a species belongs, and therefore, have an idea of the attributes that members of the genus share. Thus, it is not surprising that the scientific community continues to adopt a naming system to this day.

The International Code of Zoological Nomenclature (ICZN) is the widely accepted code in the naming of animal species. (Ref.2) They are responsible for determining the proper framing of binomial names and what to do in case of name conflicts. They provide guidelines for the proper citation of animal binomial names.

The International Code of Nomenclature for algae, fungi, and plants (ICNafp) is the code that sets the botanical names of plants, including algae and fungi. It is formerly known as the International Code of Botanical Nomenclature. (Ref.3) As for bacteria and viruses, the widely accepted governing naming systems are the International Code of Nomenclature of Bacteria (ICNB) and the International Committee on Taxonomy of Viruses (ICTV), respectively. (Ref.4,5)

These governing systems or codes operate independently of one another. ICZN, for instance, operates independently of the other binomial nomenclature ruling body, like ICNafp. Because of this, they could use generic names for animals that are already in use for plants. Thus, there are instances when the genus of a plant is encountered in animals although the two species are obviously unrelated phylogenetically.

Tautonym, where the generic name and the specific name are the same, is not allowed in ICNafp. However, it is permitted in ICZN.
The main objective of these codes is to provide a name that can be consistently used for a species that is perceptible. Animals, for example, that are within the confines of mythology will, therefore, fail to meet the criteria of being given a scientific name.

Binomial Nomenclature Examples

An example is Yucca filamentosa, a plant of the Yucca genus and the unique filamentosa species. When applying the binomial nomenclature system, the name of the species is written in italics or enclosed within the quotation marks (” “). The genus name begins in capital letter whereas the specific epithet, in small letter. The genus may also be written by abbreviating it to its initial letter. For instance, based on the previous example, Yucca filamentosa abbreviated to Y. filamentosa. The name given to a particular species is called a binomial name or scientific name.

Below is the list of some examples of common names and their binomial names:
Apple – Pyrus maleus
Banana – Musa paradiscium
Camel – Camelus camelidae
Carrot – Daucas carota
Cat – Felis catus
Deer – Artiodactyl cervidae
Dog – Cannis familiaris
Dolphin – Delphinidae delphis
Elephant – Proboscidea elephantidae
Horse – Eqqus caballus
Human – Homo sapiens
Lemon – Citrus limonium
Maize – Zea mays
Onion – Allium cepa
Orange – Citrus aurantium
Pig – Artiodactyla suidae
Pineapple – Ananus sativus
Potato – Solanium tuberosum
Rabbit – Leporidae cuniculas
Watermelon – Citrullus vulgaris
Wheat – Triticum aestivum

See Also


  1. Windelspecht, M. (2002). Groundbreaking Scientific Experiments, Inventions, and Discoveries of the 17th century. Greenwood Publishing Group. ISBN 978-0-313-31501-5.
  2. The Code Online | International Commission on Zoological Nomenclature. (2020). Iczn.Org. https://www.iczn.org/the-code/the-international-code-of-zoological-nomenclature/the-code-online/
  3. ‌International Code of Nomenclature for algae, fungi, and plants. (2011). Iapt-Taxon.Org. https://www.iapt-taxon.org/nomen/main.php
  4. ‌SP Lapage, PHA Sneath, EF Lessel, VBD Skerman, HPR Seeliger, & Clark, W. (2019). International Code of Nomenclature of Bacteria. Nih.Gov; ASM Press. https://www.ncbi.nlm.nih.gov/books/NBK8817/
  5. ‌International Committee on Taxonomy of Viruses (ICTV). (2018). International Committee on Taxonomy of Viruses (ICTV). https://talk.ictvonline.org/

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