Question

You are studying speciation in crickets. You find that males and females from different populations will mate, but no eggs get fertilized. This is an example of what type of reproductive isolating barrier?

1) Premating mating barrier
2) Prezygotic mating barrier
3) Intrinsic postzygotic
4) Extrinsic postzygotic

Answer 1

In the study of speciation in crickets where different populations' males and females mate without fertilizing eggs, the barrier encountered is a prezygotic mating barrier—specifically a gametic barrier that prevents fertilization.

Step-by-step explanation:

You are studying speciation in crickets and have found that males and females from different populations will mate, but no eggs get fertilized. This scenario is an example of a prezygotic mating barrier, specifically a gametic barrier. In these cases, the gametes (sperm and egg) are incompatible and prevent fertilization from occurring. This can occur due to structural differences in reproductive organs or differences in the gamete cells themselves. It is a reproductive isolation mechanism that occurs before a zygote (a fertilized egg) can form, hence the term prezygotic. This is opposed to postzygotic barriers, which occur after zygote formation and could involve hybrids that are inviable or sterile.