Question

How do ecologists estimate the total number of species present in the world?

• A. By counting them all
• B. By counting the number of any one species and applying this to various genus.
• C. By making statistical comparison of the temperate tropical species richness of an exhaustively studied group of insects and extrapolating this rate to other group of plants and animals
• D. By calculating the biomass of all the species.

Answer 1

Answer: (C)

Statistical comparison with the highly distributed species is done to estimate the number of species. Insects are the most diverse species of invertebrates anywhere in the world. They are taken as the standard to extrapolate the ratio to other groups of plants and animals to come up with a gross estimate of the total number of species existing in the world.