Question

List two major causes of loss of biodiversity.

Hint:

"Habitat Loss" is the number one (primary) reason for the extinction of species today.

Answer 1

Step 1: Understanding the Concept:
The "Evil Quartet" is the term used to describe the four major causes of biodiversity loss.
Step 2: Detailed Explanation:
1. Habitat Loss and Fragmentation: This is the most important cause. Examples include the clearing of tropical rainforests. When large habitats are broken into small fragments, mammals and birds requiring large territories are badly affected.
2. Over-exploitation: When humans over-harvest resources (e.g., Steller’s sea cow, passenger pigeon), it leads to extinction.
3. Alien Species Invasions: Non-native species (like Nile perch or Lantana) can cause the decline or extinction of indigenous species.
4. Co-extinctions: When a host becomes extinct, its unique parasites also perish.
Step 3: Final Answer:
Two major causes are habitat loss and over-exploitation.