Question

"The Evil Quartet" of biodiversity loss includes which of the following ?

• A. Habitat loss and fragmentation; over-exploitation; Alien species invasions; Co-extinctions
• B. Over-exploitation; Alien species invasions; Air pollution; Co-extinctions
• C. Habitat loss and fragmentation; Air pollution; Water pollution; Co-extinctions
• D. Over-exploitation; Alien species invasions; Water pollution; Co-extinctions

Hint:

The Evil Quartet: Habitat, Over-use, Aliens, Co-extinction. (Mnemonic: HOAC).

Answer 1

The Correct Option is A

The "Evil Quartet" is a term used to describe the four major causes of accelerated species extinction in the world today:
• Habitat loss and fragmentation: The most important cause (e.g., clearing the Amazon rainforest).
• Over-exploitation: Humans harvesting more than can be replenished (e.g., Steller’s sea cow).
• Alien species invasions: Introduction of non-native species that outcompete locals (e.g., Nile perch in Lake Victoria).
• Co-extinctions: When a host becomes extinct, the organisms strictly dependent on it also perish. Pollution (Air or Water), while harmful, is not considered one of the four components of the "Evil Quartet" in standard ecological texts.