The genus (genus, pl .: genera) is one of the basic classes in the Linnaeus taxonomic classification of biological classifications, and taxons belonging to that class. The genus is located below the family and above the species. Subgenus (subgenus, pl .: subgenera) may be created under the genus.
Each organism has certain characteristics and consists of a unit of species that can be clearly distinguished from other organisms to some extent (although there is some disagreement, it is a prima facie general judgment). Taxonomy attempts to compare them and systematically summarize them, but at this time, the basic structure and properties of the body are almost the same, and the group of species that can be distinguished only in the trivial part is the first. think. This is a genus.
In this case, what traits are basic and what traits are trivial depends on the taxon, and it is the taxonomist's judgment to choose them to be closer to the natural classification. For example, in the case of seed plants, the structure of flowers, the internal structure of pistils, the arrangement of vascular bundles, etc. are generally basic, and the color of flowers, the shape of leaves, etc. are more trivial traits. It is considered. In other words, the appearance of the whole plant and the structure of the flower are almost the same, the size and color of the flower and the shape of the leaf are different, and if there is no intermediate type among them, it is considered to be another species of the same genus.
However, it is thought that the problem of arbitrariness in this part, branching taxonomy that extracts as many traits as possible and leaves it to mechanical operation, and molecular genetics that is thought to reveal a more straightforward phylogenetic relationship than external morphology. Scientific methods are also being adopted. However, in any case, morphological features are often considered important, and if new methods yield different results than previous judgments, they are usually re-examined for the morphology of those species. Is.
In the first place, "genus" and "species" are words that originated in Aristotle's logic. When a collection of certain things by similarity is called "species", a more generalized one is called "genus". For example, when you say "animal is one of the creatures", the animal is the "species" and the organism is the "kind", and when you say "the insect is one of the arthropods", the insect is the "species". Arthropods are "kinds".
However, in biology, a population of homogenous individuals that is semi-permanent across generations is called a "seed", and only the first species that collects them is called a "genus". The concept of such a genus developed around the 16th century and was established by Ribinus (1652-1723) and Turnufort (1656-1708).
In Keisuke Ito's "Taisei Honzo Meiso", which introduced Carl von Linnaeus' classification to Japan for the first time, it was translated as "kind", but Udagawa Yoan's "Udagawa Keihara" 』(Shokugaku Keigen) has been used until now with the translation of" genus ".
In the currently commonly used binomial nomenclature (binomial nomenclature, binomial nomenclature), the scientific name of an organism consists of two parts. It is a genus name and a species name. For example, the scientific name Homo sapiens for humans indicates that humans are a member of the genus Homo. The initials of the genus name are always capitalized. That is, in order to recognize an organism as a new species and record it, that is, to describe the new species, the genus to which the organism belongs must be determined. The current taxonomy is basically a unit that deals with seeds, but in actual treatment,