The Origin of Species by Charles Darwin must rank as one of the most influential and consequential books ever published, initiating scientific, social and religious ferment ever since its first publication in 1859. Its full title is The Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, in some editions prefaced by the word "On."

Darwin describes the book as simply an "abstract" of his ideas, which are more fully fleshed out and supported with detailed examples in his other, more scholarly works. The Origin of Species itself was intended to reach a wider audience and is written in such a way that any reasonably educated and thoughtful reader can follow Darwin's argument that species of animals and plants are not independent creations, fixed for all time, but mutable.

This Standard Ebooks edition is based on the sixth edition published by John Murray in 1872, generally considered to be the definitive edition with many amendments and updates by Darwin himself.