Taxonomic Hierarchy and Writing Rules of Scientific Names

The format for writing scientific names of animals and plants is standardized and internationally accepted. “Scientific nomenclature” refers to various names according to a specific field of study. This article is the first in a series on scientific nomenclature within specific kingdoms. Usually, animals & plants are identified by common and scientific names. International Codes of Nomenclature Taxonomists have established several “codes” for scientific nomenclature. These codes are universal and are periodically updated by consensus. The protocol for naming species was invented in the 1700s by Swedish botanist Carl Linnaeus. Linnaeus created the system of “binomial nomenclature,” which uses only two designations–genus and specific epithet as the species name. Common names of species can vary by geographic region but a universal protocol helps avoid ambiguity and ensures consistency. Hierarchy Known as the “taxonomic hierarchy,” the system consists of several groups of species based on genetic and phylogenic characteristics. The highest level is the “kingdom.” The first kingdom comprised only two types of living organisms—animals and plants. We have seven classifications within the kingdom domain—Bacteria, Archaea, Protozoa, Chromista, Plantae, Fungi, and Animalia. Note that the designations are in Latin. This could be challenging for some who are not familiar with that language; however, the terms are globally consistent. There is no need to interpret them or translate them into another language. The levels from highest to lowest classification are as follows: Domain Kingdom Phylum Class Order Suborder Family Genus Species Subspecies Using this system, the gray wolf, for example, would be identified as follows: Domain: Eukarya. Kingdom: Animalia. Phylum: Chordata. Class: Mammalia. Order: Carnivora. Suborder: Caniformia. Family: Canidae. Genus: Canis. Species: lupus. Binomial Name The binomial name consists of a genus name and specific epithet. The scientific names of species are italicized. The genus name is always capitalized and is written first; the specific epithet follows the genus name and is not capitalized. There is no exception to this. From above example, note that the classifications go from general (Animalia) to specific (C. lupus). A species, by definition, is the combination of both the genus and specific epithet, not just the epithet. For example, we can use the term gray wolf but we cannot use just Canis or lupus to describe this animal. Canis lupus is a species. Writing Scientific Names of Animals When writing, we use both the scientific name and the “common” name on the first mention. We then choose which to use throughout and make it consistent. Gray wolf (Canis lupus) is native to North America and Eurasia. In subsequent references, we can use either the common or scientific name. If we use the scientific name, we need only to use the first letter of the genus followed by a period and the specific epithet. For example: In North America, the gray wolf was nearly hunted to extinction. In North America, C. lupus was nearly hunted to extinction. It is also common to refer to several species under one genus when you want to point out some similar characteristics within a genus. For example: All species of Canis are known to be moderate to large and have large skulls. You could also write this same information another way as follows: Canis spp. are known to be moderate to large and have large skulls. In this case, “spp.” is an abbreviation for “several species” (“sp” is the designation for one species) in the genus. Either of the above is acceptable. If you are focusing on a few species in particular, you would refer to the species name of each one. You might also see a scientific name followed by an initial or abbreviation. This would denote the person who discovered or named the species. For example, in Amaranthus retroflexus L., the L (not italicized) refers to the original name given by Linnaeus. Problems: Which of these illustrates the correct representation of the binomial scientific name for the African lion? A) Panthera leo B) panthera leo C) Panthera leo D) Panthera Leo E) Panthera leo The common housefly belongs to all of the following taxa. Assuming you had access to textbooks or other scientific literature, knowing which of the following should provide you with the most specific information about the common housefly? A) order Diptera B) family Muscidae C) genus Musca D) class Hexapoda E) phylum Arthropoda #domain #kingdom #phylum #Class #genus #ScientificNames #taxonomicHierarchy #species #phyliogeneticTree #Evolution #speciation #diagram #branchingInAPhylogeneticTree #Genetics #bilology #taxonomy #cladogram #populationGenetics #hawaiiIslands #founderEffect #geneticDrift #geneticVariation #taxa #clade #Paraphyletic #Monophyletic #Polyphyletic