On the Origin of Species the manuscript for his "big book" on Species, "Natural Selection". By mid March 1859 Darwin's abstract had reached the stage where he was thinking of early publication; Lyell suggested the publisher John Murray, and met with him to find if he would be willing to publish. On 28 March Darwin wrote to Lyell asking about progress, and offering to give Murray assurances "that my Book is not more "un"-orthodox, than the subject makes inevitable." He enclosed a draft title sheet proposing "An abstract of an Essay on the Origin of Species and Varieties Through natural selection", with the year shown
On the Origin of Species included evidence that he had gathered on the "Beagle" expedition in the 1830s and his subsequent findings from research, correspondence, and experimentation. Various evolutionary ideas had already been proposed to explain new findings in biology. There was growing support for such ideas among dissident anatomists and the general public, but during the first half of the 19th century the English scientific establishment was closely tied to the Church of England, while science was part of natural theology. Ideas about the transmutation of species were controversial as they conflicted with the beliefs that species were unchanging parts of a designed hierarchy