On The Origin of Species by Charles Darwin

English naturalist and geologist Charles Darwin first published On the Origin of Species in 1859. The idea of evolution and that all earth's species have descended from a common ancestor had already been around for some time. What was new about Darwin's work was that it found a way to explain evolution using a theory called natural selection.

It's hard to talk about The Origin of Species without making statements that seem overwrought and fulsome. But it's true: this is indeed one of the most important and influential books ever written, and it is one of the very few groundbreaking works of science that is truly readable.
To a certain extent it suffers from the Hamlet problem–it's full of clichés! Or what are now clichés, but which Darwin was the first to pen. Natural selection, variation, the struggle for existence, survival of the fittest: it's all in here.