- Temporal isolation in breeding seasons between closely related species leads to reproductive isolation. Given below are breeding seasons of different species of frogs.
Which of the above plots represents temporal isolation in breeding seasons among closely related sympatric species?
(1) Plot A (2) Plots A and B
(3) Plots B and C (4) Plots A and CWhat Is Temporal Isolation?
Temporal isolation occurs when species reproduce at different times—whether by season, month, or even time of day. This difference in timing means that even if species are physically capable of interbreeding, they rarely, if ever, encounter each other in a reproductive context. As a result, gene flow between the species is minimized or eliminated, maintaining distinct species boundaries.
Temporal Isolation in Frogs
Many studies have documented temporal isolation among frog species. For example, two frog species may inhabit the same pond, but one breeds from January to March while the other breeds from March to May. Despite their overlapping ranges, their breeding periods do not coincide, so interbreeding does not occur.
Identifying Temporal Isolation in Breeding Plots
When presented with breeding plots for different frog species, the key to identifying temporal isolation is to look for non-overlapping or minimally overlapping breeding periods among sympatric species. The correct plots will show that each species has a distinct breeding window, separated in time from the others.
For example:
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Plot A: Shows two or more species with breeding seasons that do not overlap.
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Plot C: Also may show separated breeding periods for different species.
Plots with overlapping breeding periods (like Plot B, if it shows this) do not represent temporal isolation, as the potential for interbreeding remains.
Correct Answer
The correct answer is:
(4) Plots A and C
These plots represent temporal isolation in breeding seasons among closely related sympatric frog species, as they show distinct, non-overlapping breeding periods that prevent inter-species mating and maintain reproductive isolation.
Why Temporal Isolation Matters
Temporal isolation is a key driver of speciation, especially in environments where closely related species coexist. By breeding at different times, species avoid hybridization, allowing them to evolve independently. This mechanism is observed not only in frogs but also in insects, birds, and plants, wherever timing of reproduction can serve as a barrier to gene flow.
Correct answer:
(4) Plots A and C -
