Rules of Nomenclature — Core Principles
Core Principles
The rules of nomenclature provide a universal, unambiguous system for naming organisms, essential for global biological communication. At its core is Binomial Nomenclature, introduced by Carl Linnaeus, which assigns every species a two-part scientific name: a capitalized generic name (genus) and a lowercase specific epithet (species).
These names are always italicized when typed or underlined when handwritten, and are typically derived from Latin or Greek. International codes, such as the ICN (for plants, algae, fungi) and ICZN (for animals), govern these rules, ensuring stability and uniqueness.
Key principles include the Principle of Priority, where the oldest valid name takes precedence, and the Type Concept, which links each name to a definitive reference specimen. These rules prevent confusion arising from multiple common names or duplicate scientific names, facilitating accurate identification and study of biodiversity worldwide.
Important Differences
vs International Code of Zoological Nomenclature (ICZN)
| Aspect | This Topic | International Code of Zoological Nomenclature (ICZN) |
|---|---|---|
| Organisms Covered | Plants, algae, fungi | Animals |
| Tautonyms (Genus and species epithet identical) | Not allowed (e.g., \textit{Rosa rosa} is invalid) | Allowed (e.g., \textit{Rattus rattus} is valid) |
| Starting Date for Priority | Generally 1 May 1753 (Linnaeus's \textit{Species Plantarum}) | Generally 1 January 1758 (Linnaeus's 10th edition of \textit{Systema Naturae}) |
| Retroactive Application | Rules are largely retroactive, applying to names published before the code's adoption. | Rules are largely retroactive, applying to names published before the code's adoption. |
| Homonymy across Kingdoms | A generic name can be identical to a generic name in zoology (e.g., \textit{Ficus} (plant) and \textit{Ficus} (animal) are not considered homonyms by ICN). | A generic name cannot be identical to a generic name in botany if it's considered a homonym within the animal kingdom (though the codes operate independently). |