The Evil Quartet

Is this going to be about some evil group in an distant planet out on a mission set to destroy the world?

Yes, only the evil group here isn't in an distant planet, they sitting in the very planet they want to destroy and reading this blog right now.

The evil quartet is actually a sobriquet to describe the 4 major reasons for the destruction of the biodiversity of the world.

Cause of biodiversity losses.

1. .Habitat loss and Fragmentation When plants and animals loose the land on which they are meant to survive in , they become extinct. Example:- Tropical rainforests - reduced to 14 percent to 6 percent of earth land surface.
   

2. Overexploitation It is a pretty well known fact that humans are the most greedy species in the entire planet. Not suprising that they would take from the nature to the extent that other species are driven to extinction.
   

3. Co-extinctions The lifeprocesses is deeply interlinked for various species in the environment. The extinction or reduction in one lead to the inevitable extinction of the other.
   

4. Alien species invasions When an unknown species is introduced unintentionally or deliberately turn invasive it causes the decline of the indigineous species. This is because their natural predator is missing in this new environment, this allows them to run wild and free and destroy the current habitats of the place. For example:- The Nile perch introduced into Lake Victoria in east Africa had led to the extinction of more than 200 species of fish. In India, invasive weed species like Parthenium (aka carrot grass), Lantana and water hyacinth ( Eicchoria) are causing environmental damage. Introduction of the African catfish Clarias Gariepinus poses a threat to the indigineous fishes.