If an alien were to visit Earth, the first thing that would amaze him is the enormous diversity of life on the planet.
Even humans find it astonishing and fascinating that there are so many living organisms.
Examples of the staggering variety:
More than 20,000 species of ants
3,00,000 species of beetles
28,000 species of fishes
Nearly 20,000 species of orchids
Ecologists and evolutionary biologists seek to understand this diversity by asking several important questions:
Why are there so many species?
Did such diversity exist throughout Earth’s history?
How did this diversification happen?
Why is this diversity important to the biosphere?
Would the biosphere function differently with less diversity?
How do humans benefit from this diversity?
13.1 Biodiversity
Definition:
Biodiversity refers to the combined diversity at all levels of biological organization, from macromolecules within cells to entire biomes.
The term was popularized by sociobiologist Edward Wilson.
Types of Biodiversity:
Genetic Diversity:
Refers to the variety of genes within a species.
Example: The medicinal plant Rauwolfia vomitoria in different Himalayan ranges shows genetic diversity in the potency and concentration of the chemical reserpine it produces.
In India, there are more than 50,000 genetically different strains of rice and 1,000 varieties of mango.
Species Diversity:
Refers to the variety of species in a given area.
Example: The Western Ghats have a greater diversity of amphibian species than the Eastern Ghats.
Ecological Diversity:
Refers to the variety of ecosystems in a region.
Example: India has greater ecosystem diversity than Norway with its deserts, rain forests, mangroves, coral reefs, wetlands, estuaries, and alpine meadows.
Importance of Biodiversity:
The biodiversity we see today has taken millions of years of evolution to accumulate.
However, this wealth could be lost in less than two centuries if species continue to disappear at the current rate.
Conservation of Biodiversity:
Biodiversity conservation has become a vital environmental issue of international concern.
More people are realizing the critical importance of biodiversity for human survival and well-being on Earth.
Summary:
Biodiversity is a crucial aspect of life on Earth, with diverse species, genetics, and ecosystems contributing to the stability and health of the planet.
Loss of biodiversity could have severe consequences, making its conservation essential for the future.