Arten

Arten is the plural form of the German noun Art and, in biological contexts, refers to species or distinct groups within a broader lineage. In everyday German, Arten can mean different kinds of objects or organisms; in biology it denotes the fundamental unit of classification and biodiversity.

The most widely used framework for defining Arten is the Biological Species Concept, which regards a species as a group of interbreeding natural populations that are reproductively isolated from other such groups. However, alternative concepts exist, including the morphological (based on physical appearance), phylogenetic (based on evolutionary history), and ecological (based on niche) perspectives. Delimiting Arten can be challenging, especially among bacteria and fungi where horizontal gene transfer and clonal reproduction blur boundaries.

In taxonomy, each Art has a binomial name, consisting of a genus and a species epithet, such as Homo sapiens. Subspecies may be recognized when populations diverge geographically or ecologically but can still interbreed. The concept of Arten thus underpins how scientists organize biodiversity and study evolutionary relationships.

Arten are central to biodiversity assessments, conservation planning, and ecological research. Counts of Arten (species richness) inform estimates of ecosystem health and extinction risk, but such counts depend on the species concept used and on the methods for detecting cryptic species. Many Arten face threats from habitat loss, climate change, invasive species, and overexploitation, making their preservation a global concern.

See also: Taxonomy, Binomial nomenclature, Species concept.