Biodiversity - Species on Earth and Species in India

• The total number of plant and animal species described so far is slightly more than 1.5 million.
• This figure represents formally recorded and taxonomically described organisms, not all species that exist.
• There is no clear idea of how many species are yet to be discovered and described.

• Estimates of total species vary widely, and many are only educated guesses.
• Some extreme estimates range from 20 to 50 million species.
• A more conservative and scientifically sound estimate made by Robert May places global species diversity at around 7 million.

Based on currently available species inventories:

• More than 70% of all recorded species are animals.
• Plants (including algae, fungi, bryophytes, gymnosperms, and angiosperms) account for about 22% of recorded species.
• Among animals, insects are the most species-rich group - more than 70% of all recorded animal species are insects.
• In simple terms, 7 out of every 10 animals known to science are insects.
• The number of recorded fungal species is greater than the combined total of all recorded fishes, amphibians, reptiles, and mammals.

• Ecologists do not assign reliable figures to prokaryotic diversity.
• This is because conventional taxonomy does not work well for prokaryotes, and many cannot be cultured using standard laboratory techniques.
• If molecular criteria are used for classification, prokaryotic diversity alone may run into millions of species.

Land Area vs. Species Richness

• India occupies only about 2.4% of the world's land area.
• Yet India accounts for approximately 8.1% of global species diversity.
• This disproportionate richness makes India one of the 12 megadiversity countries of the world.

Recorded Species in India

• Nearly 45,000 plant species have been recorded from India.
• The number of recorded animal species in India is approximately twice the number of plant species.

India vs World

If only 22% of total species have been recorded globally (based on May's estimate), applying this proportion to India suggests:

• India may have over 1,00,000 plant species yet to be discovered and described.
• India may have more than 3,00,000 animal species still undescribed.

This also implies that many species could become extinct before they are ever discovered.

The source compares this situation to burning a library before cataloguing all its books - a large part of biological knowledge may be lost permanently.

• While slightly over 1.5 million species have been officially recorded worldwide, scientifically sound estimates suggest the actual global total is around 7 million.
• Animals constitute more than 70% of all recorded species, with insects making up 7 out of every 10 animals, whereas plants account for roughly 22%.
• Prokaryotes are excluded from these standard estimates because conventional laboratory and taxonomic methods cannot accurately identify them, though their true numbers likely reach into the millions.
• Despite covering only 2.4% of the Earth's land area, India holds an impressive 8.1% of global species diversity, earning it the status of a megadiversity country.
• India has recorded nearly 45,000 plant species and twice as many animal species; however, estimates indicate hundreds of thousands of species remain undiscovered and face the severe threat of extinction before ever being catalogued.