Which of the following is NOT one of the major causes of accelerated…

The correct answer is Option (4) → Lightning

Species become extinct naturally, but the fast rate of extinction seen today is caused mainly by human activities. The book lists four major causes, called ‘The Evil Quartet’: habitat loss and fragmentation, over-exploitation, alien species invasions and co-extinctions. A cause that is not on this list is the answer.

Option (1) Habitat loss and fragmentation — A major cause. It is the most important cause of extinction. Cutting tropical rain forests and breaking large habitats into small pieces leaves many species with no place to live.

Option (2) Over-exploitation — A major cause. When need turns into greed, humans over-use natural resources. Steller’s sea cow and the passenger pigeon were lost this way.

Option (3) Alien species — A major cause. Some species brought in from outside turn invasive and wipe out native species, as the Nile perch did in Lake Victoria.

Option (4) Lightning — Not a major cause. Lightning is a natural event. It may start a fire or kill a few organisms, but it is not one of the four causes named in the Evil Quartet.

NCERT Extract:
Loss of Biodiversity – “… The accelerated rates of species extinctions that the world is facing now are largely due to human activities. There are four major causes (‘The Evil Quartet’ is the sobriquet used to describe them). (i) Habitat loss and fragmentation: This is the most important cause driving animals and plants to extinction. … (ii) Over-exploitation: … (iii) Alien species invasions: … (iv) Co-extinctions: When a species becomes extinct, the plant and animal species associated with it in an obligatory way also become extinct.”