Examkin

Question

Difficulty: HardBiodiversity Concepts, Hotspots and Endemism

Consider the following statements regarding Biodiversity Hotspots and Endemism:

1. Norman Myers' quantitative criteria require a region to contain at least 1,500 species of endemic vascular plants and to have lost at least 70% of its primary native vegetation to be designated as a global biodiversity hotspot.
2. Neo-endemic species refer to evolutionary ancient species that were historically widespread across continents but are currently restricted to narrow ecological refugia due to past climatic shifts.
3. Among the biodiversity hotspots overlapping Indian territory, the Nicobar Islands form part of the Sundaland hotspot, whereas the Andaman Islands are included within the Indo-Burma hotspot.

Which of the statements given above is/are correct?

  1. A
    1 and 2 only
  2. B
    2 and 3 only
  3. 1 and 3 onlyAnswer
  4. D
    1, 2 and 3

Answer

Statements 1 and 3 are correct, while Statement 2 is incorrect.
The correct answer identifies that the quantitative thresholds established by Norman Myers (1,500 endemic vascular plant species and at least 70% primary habitat loss) are accurate, and that the Nicobar Islands belong to Sundaland while the Andaman Islands belong to Indo-Burma. The second statement is incorrect because it describes palaeo-endemism rather than neo-endemism.

Step-by-Step Solution

1
Evaluate Statement 1 regarding global Biodiversity Hotspot criteria.
Statement 1 is correct.
According to Conservation International (based on Norman Myers' model), a region must meet two strict criteria: it must contain at least 1,500 species of vascular plants as endemics (>0.5% of the world's total) and it must have lost at least 70% of its original primary habitat (i.e., possess 30% or less of its original natural vegetation).
2
Evaluate Statement 2 regarding ecological and evolutionary endemism terminology.
Statement 2 is incorrect.
Phylogenetically ancient species that were once widespread but are now confined to small refugia (e.g., Ginkgo biloba or ancient conifers) are termed 'palaeo-endemics' (or relict endemics). In contrast, 'neo-endemics' are recently evolved species (often through adaptive radiation or polyploidy) that have not yet had sufficient time to expand their geographical ranges.
3
Evaluate Statement 3 regarding Indian biogeographical hotspot boundaries.
Statement 3 is correct.
India overlaps with four global biodiversity hotspots: the Himalayas, Indo-Burma, Western Ghats/Sri Lanka, and Sundaland. Biogeographically, the Nicobar archipelago belongs to the Sundaland hotspot, whereas the Andaman chain of islands falls under the Indo-Burma hotspot.

Key Concept

Hotspot Quantitative Criteria, Evolutionary Types of Endemism, and Regional Hotspot Boundaries in India
Estimated Time:2m 0s
Rate this question

Topics

Biodiversity Concepts, Hotspots and Endemism

More questions from this topic