Researchers from Tokyo Metropolitan University have shown that the environment-driven evolution of a unique ovipositor in the female fruit fly Drosophila suzukii may have caused coevolution of the male genitalia; new features were found to cause mechanical incompatibility during reproduction with similar species, impeding crossbreeding and isolating the species. The dual role of the female genitalia was found to trigger coevolution and speciation, a generic pathway which may apply to many other organisms.