Using reproductive isolation as a method of defining a species is NOT useful for
A) species whose ranges overlap.
B) species that cannot produce hybrids.
C) organisms known only from fossils.
D) organisms that reproduce sexually.

Question

Quizplus · Accepted Answer

Reproductive isolation is not useful for defining species known only from fossils because there is no way to determine if they were capable of interbreeding with other organisms.

Using Reproductive Isolation as a Method of Defining a Species