Biology · Biodiversity and Conservation · NEET
Genetic diversity is variation WITHIN a single species. Example: Rauwolfia vomitoria growing in different Himalayan ranges shows different potency and concentration of its active chemical reserpine. Species diversity is variation BETWEEN different species in an area. Example: the Western Ghats have more amphibian species than the Eastern Ghats. Rule for NEET: one species = genetic; many species = species diversity.
It is GENETIC diversity. Rauwolfia vomitoria is one single species, but the same species growing across different Himalayan ranges shows different levels of the chemical reserpine. Because the variation is inside one species, it is genetic diversity, not species diversity. Rice (over 50,000 strains) and mango (1,000 varieties) in India are also genetic diversity examples.
Because the comparison is about the number of different ECOSYSTEM types, not the number of species. India has deserts, rain forests, mangroves, coral reefs, wetlands, estuaries, and alpine meadows, so it has greater ecosystem (ecological) diversity than a Scandinavian country like Norway. Ecological diversity counts habitats/ecosystems, so it is the ecosystem level, not the species level.
Genetic diversity: Rauwolfia vomitoria (reserpine varies across Himalayan ranges), 50,000 rice strains, 1,000 mango varieties. Species diversity: Western Ghats have greater amphibian diversity than Eastern Ghats. Ecological diversity: India (deserts, rain forests, mangroves, coral reefs, wetlands, estuaries, alpine meadows) has greater ecosystem diversity than Norway. NEET often swaps these examples to trick you, so link each example to its level.
The term biodiversity was popularised by the sociobiologist Edward Wilson. It describes the combined diversity at ALL levels of biological organisation, from macromolecules within cells to biomes. The three most important levels tested in NEET are genetic, species and ecological diversity.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Genetic diversity, species diversity and ecological (ecosystem) diversity. They go from small to big: variation within a species, variation between species, and variation between ecosystems.
Genetic: Rauwolfia vomitoria showing different reserpine potency across Himalayan ranges. Species: Western Ghats having more amphibian species than the Eastern Ghats. Ecological: India having more ecosystem types than Norway.
Genetic diversity gives a species raw material to adapt and survive changing conditions. NCERT shows India has over 50,000 rice strains and 1,000 mango varieties, which is valuable for medicine (like reserpine from Rauwolfia) and agriculture.
Species diversity counts the number of different species in an area. Ecological diversity counts the number of different ecosystems or habitat types (deserts, forests, mangroves, coral reefs, etc.) in a region.
Edward Wilson, a sociobiologist, popularised the term biodiversity to describe combined diversity at all levels of biological organisation.
