After Darwin published the original 150 years of the species, biologists debated how the new species originated from ancient species and even defined the species. In the middle of June 2004, Daniel Barbash and his colleagues discovered the genes that separate species in fruit flies and published them in PLoS biological journals. It is accepted that the definition of species is that the organism is a different reproductive unit and that the same species is a descendant who is able to mate to produce inventory and is reproducible. The lack of gene exchange between species, resulting in reproductive isolation, is the core of this definition. Reproductive segregation has the phenomenon of hybrid incompatibility, and similar species can mate, but the offspring cannot survive or become infertile. The most obvious example is the mating of horses and donkeys, producing infertility. In order to clarify the molecular mechanisms of regenerating segregation, biologists must first identify genes related to infertility. The species and its related descendants are associated with a series of genes in vivo after the organism has spread outward from its ancient ancestors and produced functional changes. Daniel Barbash, Philip Awadalla and Aaron Tarone, through a variety of fruit fly species, supervised the functional heterogeneity of the genes involved in hybridization and compatibility, and determined their status as the genes that form the species.