In some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." Male ligers are sterile but some female ligers are fertile. In the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. Furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. Applying the biological species concept, the sterility of ligers reveals that .

Sterility reveals they belong to different species

Explanation:

According to the biological species concept. A species is defined as any members of a population that can interbred in nature and reproduce viable offsprings.

Despite the possibility of interbreeding tigers and lions to produce ligers.

The ligers produced are sterile.

Therefore, the sterility shows they belong to different species.

The fact that the two do not overlap naturally in the while further proves they belong to different species.

substitution is the answer in this case