Imagine two species of snakes that live in a tropical rain forest of Malaysia do not typically interbreed. In nature, one species is ground-dwelling and feeds mainly on insects and small amphibians near water, whereas the other snake feeds in the lower to mid-canopy of trees and vines rising from the forest floor. However, at a zoo in Singapore where they were kept in the same gallery exhibit, the two species were observed interbreeding and produced viable offspring. Which of the following reproductive barriers is most likely preventing these species from interbreeding in the forest? a. habitat isolation
b. gametic isolation
c. reduced hybrid viability
d. a postzygotic barrier
e. mechanical isolation

a. habitat isolation

Explanation:

Habitat isolation is a type of prezygotic reproductive barrier caused by differential habitat preferences, thereby lowering the probabilities of mating between individuals living in different habitats. Habitat isolation is a mechanism of ecological speciation that over time leads to divergence of populations and reproductive isolation. In habitat isolation, different species or populations that could interbreed with one another to produce offspring are prevented from mating as a consequence to be isolated by habitat barriers. In India, for example, lions and tigers can mate to produce offspring; however, they don't interbreed due to habitat barriers (tigers are found primarily in rainforests and lions inhabit the grasslands).