Before the cultivation of the apple tree, apple maggot flies laid their eggs exclusively on the fruit of Hawthorne trees. As apple orchards became more prominent, apple maggot flies began to lay their eggs on both the fruit of the Hawthorne tree and the fruit of cultivated apple trees. Now, apple maggot flies that live on apple trees mate and lay their eggs at different times of the year than apple maggot flies that live on Hawthorne trees. Is this an example of reproductive isolation?

Question

Quizplus · Accepted Answer

The fact that the apple maggot flies that live on apple trees and those that live on Hawthorne trees mate and lay their eggs at different times of the year suggests that they have a behavioral prezygotic barrier that prevents their gametes from encountering each other. This is an example of reproductive isolation, as the two populations have lost the ability to interbreed due to differences in their behavior, which prevents the formation of hybrid individuals. The other answer choices are incorrect because they do not accurately reflect the nature of the reproductive isolation exhibited by these fly populations.

Before the Cultivation of the Apple Tree, Apple Maggot Flies