What is the 'evil quartet'?

Explanation

The following are the .four major causes (The Evil Quartet) for accelerated rates of species extinction in the world.
Habitat loss and Fragmentation : These are the most important reasons for the loss of biodiversity.
(a) Deforestration - leads to species extinction in forests e.g : tropical rain forest once covering 14% of the earth.s land surface is now not more than 4%.
(b) Conversion of forest and agricultural land e.g : the amazon rain forest, called lungs of four planet., harbouring innumerable species is cut and cleared to cultivate soyabeans or conversion to grass lands for raising beef cattle.
(c) POllution enhances degradation of habitats and threatens the survival of many species as pollutants change the quality of the environment.
(d) Fragmentation of habitat leads to population decline e.g : mammals and birds requiring large territories and certain animals with migratory habits are badly affected.