Imagine two North American ground cricket species that contact each other as the southern species moves northward during a period of global warming. These two species do not mate much, due to differences in their courtship songs. The northern cricket does not seem to tolerate the warmer temperatures well but is limited in its ability to move north because it does not normally disperse much. Based on this information, which is the most likely outcome?

A) a behavioral reproductive isolating mechanism

B) a prezygotic isolating mechanism

C) a postzygotic isolating mechanism

D) a gametic reproductive isolating mechanism

E) two of the above

A behavioral reproductive isolating mechanism.

Explanation:

Isolating mechanisms may be defined as the mechanism that do not allow the different species to mate with each other. Two main isolating mechanisms are prezygotic isolating mechanism and a postzygotic isolating mechanism.

The behavioral isolating mechanism is a type of pre zygotic reproductive isolating mechanism in which the species are unable to meet with each other due to the differences in their courtship behavior that includes different sounds and color. The cricket species is unable to meet with each other due to difference in their courtship behavior.

Thus, the correct answer is option (A).