What is the term used to describe the phenomenon where the extinction of one species leads to the extinction of another species associated with it in an obligatory way?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Co-extinction
Some species are tied to each other so closely that one cannot live without the other, such as a host and its parasites, or a plant and its only pollinator. When one of them dies out, the other dies out too. This is called co-extinction.
Co-extinction is one of the four causes of biodiversity loss (“The Evil Quartet”). The others are habitat loss and fragmentation, over-exploitation and alien species invasions.
NCERT Extract:
Loss of Biodiversity – “… (iv) Co-extinctions: When a species becomes extinct, the plant and animal species associated with it in an obligatory way also become extinct. When a host fish species becomes extinct, its unique assemblage of parasites also meets the same fate. Another example is the case of a coevolved plant-pollinator mutualism where extinction of one invariably leads to the extinction of the other.”