What Biodiversity Is

In one line

Biodiversity is variety at three levels, and a student who says "many species" has answered a third of the question.

In exam wording: biological diversity, as defined in article 2 of the Convention on Biological Diversity 1992, means the variability among living organisms from all sources including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part, and includes diversity within species, between species and of ecosystems.

The three levels

Genetic diversity, within species. The variation among individuals and populations of the same species. It is what allows a species to adapt, and it is what a plant breeder or a pharmaceutical researcher is actually after. A crop grown from a single variety across a continent has almost none, which is why a single disease can destroy it.

Species diversity, between species. The number and relative abundance of different species in a place. This is what most people mean by biodiversity and it is one level of three.

Ecosystem diversity. The variety of habitats, communities and ecological processes. A country may have many species and few ecosystem types, or the reverse.

Why the three-level definition matters legally. Because a law that protects listed species protects only the middle level. Genetic diversity is protected by conserving populations, not individuals; ecosystem diversity by protecting areas and processes. That is why article 8 of the convention requires a system of protected areas and not merely a list of protected species.

Why it matters at all

Four reasons, and an examiner will want the fourth as well as the first three.

1. Use. Food, medicine, fibre, fuel and materials come from living things, and the genetic variety within them is the raw material of breeding and of pharmacology.
2. Services. Pollination, pest control, water purification, soil formation, flood buffering and climate regulation. The 2018 compensation judgment of the International Court of Justice priced exactly this category.
3. Insurance. Variety is resilience. A diverse system absorbs shocks that a uniform one does not.
4. Intrinsic value. The preamble to the convention opens by recognising the intrinsic value of biological diversity, before listing its ecological, genetic, social, economic, scientific, educational, cultural, recreational and aesthetic values. That word is the strongest ecocentric statement in any binding environmental treaty and it is worth citing.

India's position

India is one of the recognised megadiverse countries and contains four of the world's biodiversity hotspots: the Himalaya, the Indo-Burma region, the Western Ghats and Sri Lanka, and Sundaland including the Nicobar Islands. It is a country of origin of a very large number of cultivated plants and domesticated animals.

That status is what makes article 15 of the convention India's article. A country of origin has genetic resources other countries want, and article 15 is what lets it set the terms.