When it comes to temporal isolation, time is the barrier that prevents species from interbreeding and producing sterile hybrids. In this BiologyWise article, we intend to put forth the meaning and some examples of the concept to help you get a good understanding of the same.
Are all hybrids sterile?
Contrary to popular belief, not all hybrids are sterile. Several species of frogs, canids, and snakes can interbreed to produce fertile hybrids.
In biology, reproductive barriers are mechanisms that prevent closely related species from interbreeding. There are two types of reproductive barriers: prezygotic barriers and postzygotic barriers. While prezygotic barriers prevent mating between two closely related species, postzygotic barriers reduce the chances of an offspring after mating occurs. Of the five prezygotic barriers, temporal barriers work in a unique way, as the prevention of interbreeding in this case is attributed to the fact that the two species in question reproduce at different times of the day, season, or year.
Temporal Isolation in Biology
So temporal isolation occurs when mating between two closely related species, with overlapping range, is prevented due to the difference in the time of sexual maturity―flowering in the case of plants. If behavioral isolation revolves around the difference in mating rituals of species and mechanical isolation around the difference in their genitalia, temporal isolation revolves around the difference in their time of sexual maturity.
Simply put, the two species cannot mate because their breeding season doesn’t match. Maybe the two species breed in different seasons―one in winter and the other in fall, or maybe they mate in the same season, but at different times of the day―one during daytime and other at night.
Examples of Temporal Isolation
Besides the above examples, there are some unique cases wherein the two species in question cannot mate as a result of the difference in their breeding period, not in terms of seasons, but in terms of years.
It’s the only one of its kind!
Of the seven recognized species in genus Magicicada, three follow a 17-year mating cycle, while four follow a 13-year cycle. While species with a 17-year cycle emerge every 17 years to breed, species with a 13-year cycle emerge every 13 years. In regions where their geographic range overlaps, their emergence coincides once in every 221 years.