Question

Which of the following is referred to as the Evil Quartet with reference to the loss of biodiversity?
A. Species richness, extinctions, deforestation, erosion
B. Habitat loss and fragmentation, overexploitation, alien species invasion, co-extinction
C. Overexploitation, grazing, decomposition, extinction
D. Habitat destruction, co-extinction, deforestation, species richness
E. Grazing, erosion, deforestation, species richness

Answer 1

Hint: The world is facing an alarming rate of species’ extinction, mainly due to human activities. The four major causes of biodiversity loss are called - “The Evil Quartet”.

Complete Answer:
Jarod Diamond, had listed four principal causes for the loss of biodiversity. It was known as the 'Evil quartet'. Also called the “four horsemen of the ecological apocalypse”.
It describes the reasons which cause extinction / decrease in the number of species.
These 4 major reasons are as follows :-
1) Habitat Loss and Fragmentation - Habitat loss occurs when natural habitats are converted for humanly uses such as - urban areas, and infrastructure development, etc. Habitat fragmentation occurs when, by development, large blocks of habitat are cut into smaller pieces, like for roads or housing.
2) Over Exploitation - This means harvesting the wild species at rates much faster than at which their natural populations can recover.
3) Alien species invasions - It means introduction and/or spread of invasive alien species outside their natural past or present distribution. This threatens biodiversity.
4) Co-extinction - When a species becomes extinct, the plant and animal species essentially associated with it, may also become extinct. This is called co-extinction.

Thus, the correct option is B) Habitat loss and fragmentation, overexploitation, alien species invasion, co-extinction.

Note: Biodiversity loss means the worldwide extinction of species (whether plant or animal), as well as the local reduction or loss of species in a certain habitat. Overfishing and overhunting both, are types of overexploitation.