First published in 1859, On the Origin of Species presented Charles Darwin's theory of evolution by natural selection. The book transformed biology and influenced philosophy, religion, and science throughout the world.

This edition reproduces the historic 1859 text for modern readers, allowing modern readers to explore one of the most important works in the history of science.

On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life is a work of scientific literature by Charles Darwin that is considered to be the foundation of evolutionary biology. It was published on 24 November 1859. Darwin's book introduced the scientific theory that populations evolve over the course of generations through a process of natural selection, although Lamarckism was also included as a mechanism of lesser importance. The book presented a body of evidence that the diversity of life arose by common descent through a branching pattern of evolution. Darwin included evidence that he had collected on the Beagle expedition in the 1830s and his subsequent findings from research, correspondence, and experimentation.

Darwin supports his theory with detailed observations from plant and animal breeding, comparative anatomy, the fossil record, and the geographic distribution of species. His famous "tree of life" diagram illustrates how all species share common ancestry and branch out over time.