Spesies

Spesies is the basic unit of biological classification, referring to a group of organisms that can interbreed and produce fertile offspring under natural conditions and are reproductively isolated from other such groups. In Indonesian and Malay, spesies is used to denote the same concept, and it is commonly represented in scientific names using binomial nomenclature, for example Homo sapiens or Canis lupus.

There is no single universal definition of species. The Biological Species Concept emphasizes reproductive isolation, but this approach does not apply well to organisms that reproduce asexually or to many extinct groups known only from fossils. Other concepts—morphological, phylogenetic, and genetic—rely on shared traits, evolutionary relationships, or DNA differences. Speciation is the evolutionary process by which new species arise, often through barriers to gene flow. Models include allopatric speciation, where geographic separation plays a role, and sympatric speciation, where new species emerge within the same area.

Taxonomy and systematics classify organisms into hierarchical groups and continually refine species boundaries as new data become available. Challenges include cryptic species that are difficult to distinguish morphologically, variable populations, and incomplete fossil records. Accurate species delimitation is important for biology, ecology, and conservation, because protection and management decisions often hinge on recognizing distinct species.

Examples include Homo sapiens (humans) and Canis lupus (wolves), with domestic dogs classified as a subspecies of Canis lupus. The concept of spesies also helps describe biodiversity patterns such as rings of related populations that gradually change across landscapes yet form a single species in some areas and separate species in others.