How many species of insects are there of 2017

There are at least 900,000 species, but many more probably have yet to be discovered. Insects all have bodies consisting of a head, a thorax of three segments, usually three pairs of legs and often one or two pairs of wings. Their heads have compound eyes and long antennae that are sensitive to touch and smell.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".