There are various factors are responsible for reproductive isolation during the period of geographical isolation. 1. Species specific breeding season: in this the species of same genus having different time for breading will not able to interbreed. Failure of fertilization of egg: this is also happen even the species are interbred. 2. Prezygotic isolation- 3. Postzygotic isolation- Solution There are various factors are responsible for reproductive isolation during the period of geographical isolation. 1. Species specific breeding season: in this the species of same genus having different time for breading will not able to interbreed. Failure of fertilization of egg: this is also happen even the species are interbred. 2. Prezygotic isolation- 3. Postzygotic isolation-.