Question

Identify the major threats to Biodiversity, that is, the evil quartette from the following:
I. Invasion of local species
II. Over exploitation
III. Introduction of alien species
V. Habitat loss
VII. Co-extinction

• A. I, III, VI, VII
• B. I, II, V, VII
• C. II, III, V, VII
• D. III, IV, VI, VII

Hint:

Habitat loss is the number one cause of species extinction worldwide.
Fragmentation divides large habitats into smaller patches, which particularly harms large mammals and migratory birds.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks to identify the four primary drivers of modern species extinction, collectively referred to by ecologists as "The Evil Quartet."

Step 2: Key Concepts and Approach:
We evaluate the major human-induced threats to global biodiversity as outlined by conservation biology.
The four components of the "Evil Quartet" are:
1. Habitat loss and fragmentation
2. Over-exploitation
3. Alien species invasions
4. Co-extinctions

Step 3: Detailed Explanation:

• V. Habitat loss and fragmentation: This is the single most important cause of animal and plant extinctions (e.g., deforestation of the Amazon rainforest).

• II. Over-exploitation: Humans over-utilize natural resources, leading to the collapse of populations (e.g., Passenger pigeon, Steller's sea cow).

• III. Alien (exotic) species invasions: Introducing non-native species often disrupts local food webs, leading to the decline or extinction of indigenous species (e.g., Nile perch introduced into Lake Victoria).

• VII. Co-extinction: When a species becomes extinct, any obligate mutualistic species associated with it must also face extinction (e.g., host-parasite pairs, co-evolved plant-pollinator systems).


Step 4: Final Answer:
The combination representing the "Evil Quartet" is II, III, V, and VII, corresponding to option (C).