On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection main subject natural selection
"On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection" is the title of a journal article, comprising and resulting from the joint presentation of two scientific papers to the Linnean Society of London on 1 July 1858: On The Tendency of Varieties to Depart Indefinitely from the Original Type by Alfred Russel Wallace and an Extract from an unpublished Work on Species from Charles Darwin's Essay of 1844. The article also includes an Abstract of a Letter from Darwin to Asa Gray, and an introductory letter by Joseph Dalton Hooker and Charles Lyell. The article was the first announcement of the Darwin–Wallace theory of evolution by natural selection; and appeared in print on 20 August 1858. The presentation of the papers spurred Darwin to write a condensed "abstract" of his "big book" on Natural Selection. This was published in November 1859 as On the Origin of Species.Events leading up to the publication
On the voyage of the Beagle the young Charles Darwin took a break between graduating and starting his career as a clergyman to study the natural history of South America, an interest he had developed at the University of Edinburgh and the University of Cambridge. Influenced by Charles Lyell's Principles of Geology, he became an able geologist as well as collecting plant and animal specimens, and fossils of gigantic extinct mammals. By the return journey, he was connecting patterns of geographical and historical distribution, and starting to doubt the stability of Species. In September 1838 he conceived his theory of natural selection as the cause of evolution, then as well as developing his career as a geologist and writer worked privately on finding evidence and answering possible objections. He wrote out his ideas in an 1842 "pencil sketch", then in an essay written in 1844. He discussed transmutation with his friend Joseph Dalton Hooker, who read the essay in 1847. After turning his attention to biology and completing eight years of work on barnacles, Darwin intensified work on his theory of species in 1854.
Alfred Russel Wallace, a naturalist working in Borneo, had a paper on the "introduction" of species published in Annals and Magazine of Natural History. This made guarded comments about evolution, and in the spring of 1856 it was noticed by Lyell who drew it to the attention of Darwin who was then working out a strategy for presenting his theory. Darwin apparently mistook Wallace's meaning, writing "nothing very new ... Uses my simile of tree, [but] it seems all creation with him". However, he spelt out the details of Natural Selection to Lyell, who found the idea hard to accept but urged Darwin to publish to establish priority. On 14 May 1856 Darwin began what became his draft for a book titled Natural Selection.
Wallace collected specimens and corresponded with Darwin from Borneo. In December 1857, he wrote to ask if Darwin's book would delve into human origins, to which Darwin responded that "I think I shall avoid the whole subject, as so surrounded with prejudices, though I fully admit that it is the highest & most interesting problem for the naturalist". He encouraged Wallace's theorising, saying "without speculation there is no good & original observation", adding that "I go much further than you".
Wallace wrote his paper On The Tendency of Varieties to Depart Indefinitely from the Original Type at Ternate in February 1858 and sent it to Darwin with a request to send it on to Lyell. Darwin received it on 18 June 1858, and wrote to Lyell that "your words have come true with a vengeance,... forestalled" and "If Wallace had my MS. sketch written out in 1842, he could not have made a better short abstract!" While Wallace had not asked for publication, Darwin would, "of course, at once write and offer to send [it] to any journal" that Wallace chose. He sadly added that "all my originality, whatever it may amount to, will be smashed". Lyell's immediate response urged Darwin to publish his own ideas, and in his reply of 25 June Darwin agreed that he could point to his own Essay of 1844 which Hooker had read in 1847, and a letter to Asa Gray of 1857 showing that he was still developing the ideas, "so that I could most truly say and prove that I take nothing from Wallace. I should be extremely glad now to publish a sketch of my general views in about a dozen pages or so. But I cannot persuade myself that I can do so honourably... I would far rather burn my whole book than that he or any man should think that I had behaved in a paltry spirit", also requesting that Hooker be invited to give a second opinion. Darwin was overwrought by a deepening crisis of illness of his baby son Charles Waring Darwin, who died of scarlet fever on 28 June. On the morning of the 29th he acknowledged Hooker's letters, writing "I cannot think now", then that night he read the letters, and though "quite prostrated", got his servant to take to Hooker Wallace's essay, the letter to Asa Gray and the Essay of 1844, leaving matters in the hands of Lyell and Hooker.Lyell and Hooker had decided on a joint publication at the Linnean Society of London of Wallace's paper together with an extract from Darwin's essay and his letter to Asa Gray. The last meeting of the society before the summer recess had been postponed following the death of former president the botanist Robert Brown on 10 June 1858, and was to be held on 1 July.
On the afternoon of 30 June Mrs. Hooker copied out extracts from the handwritten documents they had just received from Darwin, then that evening Lyell and Hooker handed them in to the secretary with a covering letter.