On 20 August 1858 Charles Darwin and Alfred Russel Wallace published “On the tendency of species to form varieties; and on the perpetuation of varieties and species by natural selection” in the Journal of the Proceedings of the Linnean Society, the most important society for the study and diffusion of information about natural history, evolution, and taxonomy.
That was the first printed formal exposition of the “Theory of Evolution by Natural Selection”, the greatest single leap of progress made in biology,
On 24 November 1859 Darwin published “The origin of the Species”, the book that handed him over to history. It introduced the scientific theory that populations evolve over the course of generations through a process of natural selection.
He had been working on that theory over a period of nearly two decades, revealing to a few other natural scientists his godless supposition. He had confessed to a close friend, botanist Joseph Dalton Hooker: “It is as if one were confessing to a murder”.
The book was written for non-specialist readers, consequently it was easily accessible to all and succeeded in involving an enormous share of the public.
Darwin ended with a passage that became well known and much quoted:
“There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.”
It opposed creationism, that’s why some scientists of the day argued over it violently, but the huge evidence from palaeontology, genetics, zoology, molecular biology and other fields gradually established evolution’s truth beyond reasonable doubt.
However, 160 years after the publication of Darwin’s studies, his theory of evolution still clashes with the creationist beliefs of some organized religions.