Reproductive Isolation Short Note | Evolution Class 12 Notes

In this article we will discuss about Reproductive Isolation :- Prezygotic isolation and  Postzygotic isolation

• Prevention of inter breeding between the population of two different or closely related species
• Reproductive isolation was explained by stebbian
• Two types reproductive isolation are
  1. Prezygotic isolation
  2. Postzygotic isolation

1. Prezygotic isolation

• Prevention of mating and the formation of zygote
  • Temporal isolation: Due to difference in breeding seasons of two species
  • Ecological isolation: Due to different habitats of two species
  • Behavioral isolation: Due to different sexual or coitus behavior of two species

2. Postzygotic isolation

• The organisms mate but no offspring are produced
  • In viability: Zygote fails to develop
  • Sterility: Adults are sterile and do not produce gametes
  • Hybrid Breakdown: Sometimes inter specific mating produces a hybrid, but progeny is weak, abnormal or sterile.