The theory of Natural Selection was put forward in

Solution (By Examveda Team)

The theory of Natural Selection was put forward in 1859.
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, if useful, is preserved".
The concept was simple but powerful: individuals best adapted to their environments are more likely to survive and reproduce.