Question 73 from UPSC CSE 2024 - Environm ent

Question

Which one of the following shows a unique relationship with an insect that has coevolved with it and that is the only insect that can pollinate this tree?

IASCODEX · Accepted Answer

Correct Option: A. Fig

Strategy: Focus on the phrase 'unique relationship' and 'only insect that can pollinate this tree'. Such obligate mutualism is famously exhibited by the fig and its specific wasp pollinator, known widely in ecology. The other trees mentioned have multiple pollinators, so only fig fits this exclusive coevolutionary relationship.

Key Info: Figs (genus Ficus) and fig wasps (family Agaonidae) display a classic example of coevolution and obligate mutualism. Every fig species is typically associated with a unique species of wasp, which is both pollinator and reproductive partner. The reproductive cycle of the wasp is intricately tied to the lifecycle of the fig as the wasp lays its eggs inside the fig receptacle and, in the process, pollinates the enclosed flowers. This mutual specificity is highly documented in biology—most Ficus species cannot be pollinated except by their partner wasp species, and vice versa. Mahua (Madhuca longifolia), Sandalwood (Santalum album), and Silk cotton (Ceiba pentandra) are pollinated by multiple agents—ranging from various insects, birds to bats—showing no such obligate, one-to-one coevolved partnership. The fig–fig wasp case is a textbook instance in ecology and evolution, often used to exemplify specialized plant–insect interactions.

IASCODEX · Answer

Option B: Mahua

IASCODEX · Answer

Option C: Sandalwood

IASCODEX · Answer

Option D: Silk cotton