The Himalayan Range is very rich in species diversity. Which one among the following is the most appropriate reason for this phenomenon?
Answer & explanation
Answer: (b) It is a confluence of different biogeographical zones
The Himalaya lies in a transition zone where the Palaearctic realm meets the Indo-Malayan realm. Species from both realms are found there. This mixing has caused a proliferation of species, and it is the main reason for the range's richness.
- ✗ (a) Rainfall differs widely across the Himalaya, from wet in the east to dry in the trans-Himalaya. So high rainfall cannot explain richness across the whole range. The richness comes from the meeting of different biogeographic realms, not from rainfall.
- ✓ (b) The Himalaya straddles a transition zone between the Palaearctic and Indo-Malayan realms, and species from both are found there. This mixing of communities has caused a proliferation of species, which makes the range very rich in diversity.
- ✗ (c) Exotic and invasive species are present in the Himalaya. In any case, the absence of introduced species would not by itself create species richness.
- ✗ (d) The Himalaya is not free of human pressure; people settle, farm and use forests across the range. Less human interference may help species survive, but it does not explain why so many species are there in the first place.
Remember · The Himalaya is rich in species because it is a transition zone where the Palaearctic and Indo-Malayan biogeographic realms meet, so species from both realms are found there.
Sources
- Himalayan Biodiversity (G.B. Pant National Institute of Himalayan Environment, MoEFCC), 2013 ↗ “The Himalaya thus represents a mixing ground of Palaearctic and Indo- Malayan communities, which has caused a proliferation of species usually not found outside the tropics.”
- ICIMOD – Biodiversity of the Hindu Kush Himalaya ↗ · reference work “Biogeographically, the Hindu Kush Himalayas straddles a transition zone between the Palearctic and Indo-Malayan realms. Species from both realms are found in the region”
Question: UPSC Civil Services (Preliminary) 2011, General Studies Paper I. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). ·
