Taxons are a group consisting of a certain number of animals, united on the basis of some characteristics. As the Encyclopædia Britannica says:
Taxon - any units used in the science of biological classification or taxonomy. The taxa are arranged in a hierarchy from kingdom to subspecies, and each taxon usually includes several taxa of lower rank. In the classification of protozoa, plants and animals, some taxonomic categories are generally recognized.
There are many terms for genetically controlled variants within a species, but these names are not usually considered taxa. In the polymorphic form, the terms "morphine" and "variety" are often used. Among domestic animals, a genetically pure line is usually referred to as a breed. In botany, the term cultivar is applied to a recognizable variant that results from cultivation.
General information
Biologists group and classify both extinct and living species of organisms using the conceptual framework of scientific (or biological) classification: scientific systematization or taxonomy. The taxon denotes a speci altaxonomic grouping of organisms. Mammals, for example, are a taxon of vertebrates. These include the Mammalia class.
Taxonomic rank (species, category, group) refers to the taxon level in the given hierarchy. Placed at a certain ordinal level, they are groups of organisms with the same classification index. The eight main categories used to rank organisms are species, genus, family, order, class, phylum or division, kingdom, and domain (in biology, the terms "division" and "type" occupy the same taxonomic rank: "phylum" traditionally applied to animals, while "separation" is more commonly applied to plants and fungi).
Prefixes and suffixes
Biologists use a prefix added to one of the eight major ranking categories to indicate finer differences in rank than is possible with existing ones. The prefix "super-" indicates a rank higher, the prefix "sub-" indicates a position one step lower. In zoology, the prefix "infra-" means an additional rank difference, lower than sub-.
For example, the International Code of Zoological Nomenclature says that a taxon is:
"The level, for nomenclatural purposes, of a taxon in the taxonomic hierarchy (eg, all families are for nomenclatural purposes at the same rank, which is between superfamily and subfamily). The series of family group, genus and species groups, the group in which nominal taxa can be established, are set out inArticles 10.3, 10.4, 35.1, 42.1 and 45.1" International Commission on Zoological Nomenclature (1999)
Linnaeus
Modern classification goes back to the system of C. Linnaeus, who grouped species according to common physical characteristics. A similar distribution of genera and species in the animal and plant kingdoms was made to reflect the Darwinian principle of general descent.
By differentiating the Linnaean-based classification, which is used for biological designation, and the modern taxonomy proposed by Decandole, scholars distinguish between taxa/taxonomy and classification/systematics. The first relates to biological names and naming rules. The combination of the latter refers to the ranking of taxa according to putative evolutionary (phylogenetic) relationships.
The rank of an organism is relative and limited to a certain systematic scheme. For example, liverworts have been grouped in various classification systems as family, order, class, or division (type). Crustaceans (Crustacea) are variously grouped as a phylum, subphylum, superclass, or class. Many animal taxa have also undergone a variety of changes over time.
Disputes
The use of a set of ranks is disputed by users of cladistics (in Greek, "cladistics" means "branch"). In addition, the class rank is quite often not evolutionary, but a phenetic and paraphyletic group, in contrastfrom those steps managed by the ICZN cannot be made monophyletic by exchanging the taxa they contain. This led to phylogenetic taxonomy and the ongoing development of the Philocode (scientific compendium) which should govern the application of taxa to species.
Carl Linnaeus developed a linear taxonomy using a six-level ranking scale: kingdom, class, order, genus, species and diversity. Today's animal taxa are still very similar to the Linnean scale, with the addition of two major ranks and a family (with a de-emphasis on diversity). The nomenclature is governed by codes that are appropriate for this, but despite this, there are slightly different titles for zoology and botany.
In both zoology and botany, systematic taxa are usually assigned to a taxonomic rank in a hierarchy, and organisms are identified by combining the two main ones in modern nomenclature: genus and species. The resulting two-word binomial name is the world used to describe the particular species. For example, the binomial name of a person is Homo sapiens. It is italicized when typing and underlined when writing. The first word refers to a genus, which is a broad grouping of closely related species. The second lowercase word always indicates the species by which the organism is designated in its genus. For example, we know the butterfly Samia Cynthia (Ailanthus silkworm).
Her taxon order is:
- Kingdom: Animals.
- Type: Arthropod.
- Class: Insects.
- Squad: Lepidoptera.
- Suborder: Proboscis.
- Family: Peacock-eyes.
- Subfamily: Arsenurinae.
- Genus: Samia.
- Species: Ailanthus silkworm.
Finishing
In the end, I would like to say that many scientists are trying to challenge the modern established traditions of taxonomy, but they do not succeed. This is due to the fact that the classification of species based on the ruler of Carl Linnaeus has proven to be the most effective and suitable for work.
Interesting to know: sometimes the wrong pronunciation of the names of foreign brands in Russian brings confusion into people's minds. For example, they translate the famous brand of Japanese cars Hyundai Tucson as "Hyundai-Tucson". In this case, the word "taxon" does not apply to biological categories.