Imagine two species of snakes that live in a tropical rainforest of Malaysia do not typically interbreed. In nature, onespecies is ground-dwelling and feeds mainly on insects and smallamphibians near water, whereas the other snake feeds in the lowerto mid-canopy of trees and vines rising from the forest floor.However, at a zoo in Singapore where they were kept in the samegallery exhibit, the two species were observed interbreeding andproduced viable offspring. Which of the following reproductivebarriers is most likely preventing these species from interbreedingin the forest?
- habitat isolation
- gametic isolation
- reduced hybrid viability
- a postzygotic barrier
- mechanical isolation
