Write an explanatory note on Biodiversity.

(N/A) Biodiversity refers to the immense diversity or heterogeneity that exists at all levels of biological organization, ranging from macromolecules within cells to biomes.
There are more than $20,000$ species of ants, $3,00,000$ species of beetles, $28,000$ species of fishes, and nearly $20,000$ species of orchids.
The term 'Biodiversity' was popularized by the sociobiologist Edward Wilson to describe the combined diversity at all levels of biological organization.
Levels of biodiversity:
$(i)$ Genetic diversity: It is the diversity at the genetic level within a single species. For example, there are about $1,000$ varieties of mango $(Mangifera \text{ } indica)$ and $50,000$ strains of rice in India. Genetic diversity allows a species to adapt better to changing environmental conditions. It is considered the raw material for speciation.
$(ii)$ Species diversity: It refers to the variety of species within a region. The measurement of species diversity is its richness, i.e., the number of species per unit area. For example, the Western Ghats have a greater amphibian species diversity than the Eastern Ghats.
$(iii)$ Ecological diversity: It is the diversity at the ecosystem level. India, with its deserts, rain forests, mangroves, coral reefs, wetlands, estuaries, and alpine meadows, has greater ecosystem diversity than a Scandinavian country like Norway. It can be of $3$ types:
- Alpha $(\alpha)$ diversity: Diversity of organisms within the same community.
- Beta $(\beta)$ diversity: Diversity between communities.
- Gamma $(\gamma)$ diversity: Diversity over the entire geographical area.