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.
In our biosphere immense diversity (or heterogeneity) exists not only at the species level but at all levels of biological organisation ranging from macromolecules within cells to biomes.
1
Biodiversity is the term popularised by the to describe the combined diversity at all the levels of biological organisation.
(i) Genetic diversity: A single species might show high diversity at the genetic level over its distributional range.
The most important TYPES OF BIODIVERSITY ARE..
The genetic variation shown by the medicinal plant Rauwolfia vomitoria growing in different Himalayan ranges might be in terms of the potency and concentration of the active chemical (reserpine) that the plant produces.
India has more than 50,000 genetically different strains of rice, and 1,000 varieties of mango
GENETIC DIVERSITY
Species diversity: The diversity at the species level. For example, the Western Ghats have a greater amphibian species diversity than the Eastern Ghats.
Ecological diversity: At the ecosystem level, India, for instance, with its deserts, rain forests, mangroves, coral reefs, wetlands, estuaries, and alpine meadows has a greater ecosystem diversity than a Scandinavian country like Norway.
PART-2
IUCN
2004
According to the IUCN (2004), the total number of plant and animal species described so far is slightly more than 1.5 million
Some extreme estimates range from 20 to 50 million, but a more conservative and scientifically sound estimate made by Robert May places the global species diversity at about 7 million.
For many taxonomic groups, species inventories are more complete in temperate than in tropical countries. Considering that an overwhelmingly large proportion of the species waiting to be discovered are in the tropics
TEMPERATE V/S TROPICAL
Biologists make a statistical comparison of the temperate-tropical species richness of an exhaustively studied group of insects and ......
...extrapolate this ratio to other groups of animals and plants to come up with a gross estimate of the total number of species on earth.
More than 70 per cent of all the species recorded are animals, while plants (including algae, fungi, bryophytes, gymnosperms and angiosperms) comprise no more than 22 per cent of the total.
Among animals, insects are the most species-rich taxonomic group, making up more than 70 per cent of the total.
That means, out of every 10 animals on this planet, 7 are insects
The number of fungi species in the world is more than the combined total of the species of fishes, amphibians, reptiles and mammals.
It should be noted that these estimates do not give any figures for prokaryotes. Biologists are not sure about how many prokaryotic species there might be.
The problem is that conventional taxonomic methods are not suitable for identifying microbial species and many species are simply not culturable under laboratory condition.
If we accept biochemical or molecular criteria for delineating species for this group, then their diversity alone might run into millions.
India has only 2.4 per cent of the world’s land area, its share of the global species diversity is an impressive 8.1 per cent.
That is what makes our country INDIA one of the 12 mega diversity countries of the world.