April 5, 1859 n this day, Charles Darwin, W English naturalist and geologist, sent to his publishers the first three chapters of the book Origin of Species.

Darwin held off his theory of `evolution and natural selection` for years as many scientist and researchers before him who had published radical theories were greatly criticised and many faced dire circumstances.

Therefore, when he developed thetheory, he kept it a secret. It was only when another scientist started publishing papers having similar ideas that Darwin gave the book for publishing.

The book appeared in November 1859, and became one of the most influential books ever published.•