Question

A scientist tries to mate the two similar-looking fruit flies Drosophila melanogaster and Drosophila simulans. But he finds that they are unable to produce viable offspring.What kind of evolutionary barrier could this be?

Answer 1

The evolutionary barrier is Reproductive Isolation. This mechanism ensures that organisms of different species can not produce offspring. In some cases, such as Mules, the two organisms CAN produce offspring, but the offspring will not be fertile.