Species

Species is the basic unit of biological classification. The study of species is a historical process, but there is currently no universally agreed definition of living species. The traditional definition of species is the concept of morphological species; a species is a group of individuals with similar forms, and the basic structure is the individual. The prevailing definition is that species are groups of natural populations that can communicate with each other for reproduction and are segregated from other groups reproductively. As such, the basic structure of species is the population rather than the individual, and the concept of a social group is emphasized. In biology, the standard of reproductive segregation of species is only applicable to sexual species but is not applicable to asexual species or fossil species. The classification of asexual and fossil species emphasizes the morphological concept, in which species are judged based on the continuity of their morphological...