Genus

The term genus is one of the seven major classification groups that biologists use to identify and categorize living things. These seven groups are hierarchical or range in order of size, and genus is one of the smaller, important, and more frequently used groups. The classification scheme for all living things is: kingdom, phylum, class, order, family, genus, and species.

Coming as it does between the larger group, family, and the smaller group, species, members of the same genus have more in common than those in the same family and less than those in the same species. Although members of the same genus are very similar (like a wolf and a coyote), members of different groups usually cannot breed with one another. Members of the same genus, however, are known to be very closely related in terms of their evolutionary history, and it is obvious that they share the same basic shape and structure as well as similar biochemistry (the chemistry of biological processes) and even behavior.

The group genus is almost always used with the more particular grouping, species. All organisms are referred to scientifically by a two-word, Latin name called a binomial. Humans therefore are Homo sapiens. This example of Homo is unusual, for only one living species occurs in that genus. Most genera are "polyspecific" and contain more than one species. This is especially the case for plants known as sedges (Carex) and insects known as fruit flies (Drosophila), each which has hundreds of species in the genus.

[See alsoClass; Classification; Family; Genus; Kingdom; Order; Phylum; Species ]