Question

A population of fruit flies on an island lay their eggs in some rotting fruit. Some of the fruit is blown into the ocean by a storm and washes up on another island that is too far apart for the flies to fly back to their original island. Over time the two populations change so much that they are different species. What must be true of the two populations of flies at this point?

Answer 1

That they can no longer breed together to reproduce fertile offspring.