Thoughts on the possibility of transmutation of species which he recorded in 1836 towards the end of his five-year voyage on the Beagle were followed on his return by findings and work leading to him conceiving his theory in September 1838. He gave priority to his career as a geologist whose observations and theories supported Charles Lyell’s uniformitarian ideas, and to publication of the findings from the voyage as well as his journal of the voyage, but he discussed his evolutionary ideas with several naturalists and carried out extensive research on his "hobby" of evolutionary work.
He was writing up his theory in 1858 when he received an essay from Alfred Russel Wallace who was in Borneo, describing Wallace's own theory of natural selection, prompting immediate joint publication of extracts from Darwin's 1844 essay together with Wallace's paper as On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection in a presentation to the Linnaean Society on 1st July 1858. This attracted little notice, but spurred Darwin to write an "abstract" of his work which was published in 1859 as his book On the Origin of Species.
Natural history at that time was dominated by clerical naturalists who saw their science as revealing God's plan, whose income came from the Established Church of England. Darwin found three close allies. Books by the eminent geologist Charles Lyell had influenced the young Darwin during the Voyage of the Beagle and he then befriended Darwin who he saw as a supporter of his ideas of gradual geological processes with continuing divine Creation of species. By the 1840s Darwin became friends with the young botanist Joseph Dalton Hooker who had followed his father into the science, and after going on a survey voyage used his contacts to eventually find a position. In the 1850s Darwin met Thomas Huxley, an ambitious naturalist who had returned from a long survey trip but lacked the family wealth or contacts to find a career and who joined the progressive group around Herbert Spencer fighting to make science a profession, freed from the clerics.
Darwin made attempts to open discussions about his theory with his close scientific colleagues. In January 1842 Darwin sent a tentative description of his ideas in a letter to Lyell, then prepared a "Pencil Sketch" of his theory. He worked up his "Sketch" into an "Essay" in 1844, and eventually persuaded Hooker to read a copy in January 1847. By September 1854 Darwin's other books reached a stage where he was able to turn his attention fully to Species, and from this point he was working to publish his theory. In 1856 he was still bringing his friends round towards accepting evolution as a process, and was far from convincing them about the mechanism, but then Wallace's entry into the discussion brought a new urgency to publication.
By July Darwin had decided to produce a full technical treatise on species. Lyell seemed to be coming round to Darwin's ideas, but in private was agonising over the social implications if humans had animal ancestry, particularly now that race was becoming an issue, with Robert Knox describing races as different species and warning of racial wars. Hooker's verdict on the growing manuscript was "incomparably more favourable" than Darwin had anticipated, while Darwin tried to put over the point that "external conditions do extremely little", it was the selection of "chance" variations that produced new species.
Darwin's experiments on how species spread were now extended to considering how animals such as snails could be carried on birds' feet, and seeds in birds' droppings. His tenth child, Charles Waring Darwin was born on 6 December apparently without his full share of intelligence, renewing fears of inbreeding and hereditary defects, a topic that he covered in principle in his book.
On 23 February 1857 the Darwins were visited for lunch by Robert FitzRoy, who had been the captain of HMS Beagle during Darwin's voyage, together with his second wife, his first wife and his only daughter having died.
Darwin's cousin William Darwin Fox remained a mainstay, warning him against overworking on his huge book and recommending a holiday, but Darwin was immersed in his experiments and his writing. "I wish I could set less value on the bauble fame, either present or posthumous... yet, if I know myself, I would work just as hard, though with less gusto, if I knew that my Book would be published for ever anonymously."
Darwin pressed on, overworking, until in March 1857 illness began cutting his working day "ridiculously short". He took a fortnight's water treatment at the nearby Moor Park spa run by Dr. Edward Lane, and this revived him. Wallace had contacted Darwin earlier and was now working for him, sending domestic fowl specimens from Indonesia. Darwin wrote to Wallace from the spa "I can see that we have thought much alike & to a certain extent have come to similar conclusions...This summer will make the 20th year (!) since I opened my first note-book, on what way do species & varieties differ from each other...I am now preparing my work for publication...do not suppose I shall go to press for two years...I have slowly adopted a distinct & tangible idea,– whether true or false others must judge". On his return a cold and social pressure set back the recovery. He had to return to the spa, finishing "variation" in July and posting pages to Huxley for checking.
Others helped with providing information, including Asa Gray on American plants. Darwin wrote to Gray saying that he had "come to the heterodox conclusion that there are no such things as independently created species – that species are only strongly defined varieties. I know that this will make you despise me". An intrigued Gray admitted to his own belief that there was some law or power inherent in plants making varieties appear, and asked if Darwin was finding this law. Realising that Gray had not grasped what he was suggesting, Darwin sent him a letter on 5 September 1857 giving a brief but detailed account of his views. He included a copy made by the schoolmaster of his draft book which he had named Natural Selection. Gray responded, warning against personifying natural selection which simply described ways of winning life's race rather than being "nature's guiding hand". Darwin asked Gray to maintain secrecy. The young guard of naturalists were now putting the "mode of creation" openly on the agenda, even in addresses to the Geological Society, but Darwin wanted his case to be fully prepared.
Joseph Dalton Hooker, John Tyndall and Thomas Huxley now formed a group of young naturalists holding Darwin in high regard, basing themselves in the Linnean Society of London which had just moved to Burlington House, Piccadilly, London, near the Royal Society. Huxley had not yet understood natural selection despite Darwin's hints about pedigree and genealogical trees. Huxley's attention was focussed on defeating the dominant orthodoxy of the arrogant Owen.
Darwin's attention turned from pigeons to seedlings, experimenting with subjecting plants to conditions which might produce variation. His family helped with this and with tracking bees, experimenting (unsuccessfully) to try to find out what would influence their flight path.
His wife Emma Darwin was now known throughout the parish for helping in the way a parson's wife might be expected to, and as well as providing nursing care for her own family's frequent illnesses she gave out bread tokens to the hungry and "small pensions for the old, dainties for the ailing, and medical comforts and simple medicine" based on Dr. Robert Darwin's old prescription book. Charles Darwin also took on local duties, increasing his social standing by becoming a Justice of the Peace and a magistrate. To accommodate the needs of his large family and accommodate visiting cousins further house extensions got under way. In November he escaped the worries for a week's recuperation at Dr Lane's Moor Park spa.
As Darwin pressed on with his Natural Selection manuscript in December 1857, Wallace wrote to ask if it would delve into human origins. Sensitive to Lyell's fears on this, 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".
Huxley used his March 1858 Royal Institution lecture to claim that structurally gorillas are as close to humans as they are to baboons. He added "Nay more I believe that the mental & moral faculties are essentially & fundamentally the same kind in animals & ourselves". This was a clear challenge to Owen's lecture claiming human uniqueness, given at the same venue. In a subsequent lecture Huxley stated that if there was a solution to the problem of species, it "must come from the side of indefinite modifiability", an indication that he was moving towards Darwin's position. In June he used his lecture at the Royal Society to attack Owen's "etherial archetype". Having gained a foothold in science with the aid of the Westminster Review group led by John Chapman and Herbert Spencer, Huxley was out to dislodge the domination of science by wealthy clergymen– led by Owen– instead wanting to create a professional salaried scientific civil service. To Spencer, animal species had developed by "adaptions upon adaptions". Huxley was using arguments on origins to split science from theology, arguing that "it is as respectable to be modified monkey as modified dirt".
There were differences, though these were not evident to Darwin on reading the paper. Wallace's idea of selection was the environment eliminating the unfit rather than cut-throat competition among individuals, and he took an egalitarian view of the Dayak natives he was among, while Darwin had seen the Fuegians as backwards savages, albeit capable of improvement.
It had come at a bad time, as his favourite retreat at Moor Spa was threatened by Dr Lane being put on trial accused of adultery, and five days later Darwin's baby Charles Waring came down with scarlet fever. Darwin's first impression had been that though it meant losing priority, it would be dishonourable for him to be "induced to publish from privately knowing that Wallace is in the field", but Lyell quickly responded strongly urging him to reconsider. Darwin's reply of 25 June was a plea for advice, noting that the points in Wallace's sketch had been fully covered in his own Essay of 1844 which Hooker had read in 1847, and that he had also set out his ideas in a letter to Asa Gray in 1857, "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". He added a request that Hooker be informed to give a second opinion.
Darwin was overwrought when baby Charles Waring Darwin died on 28 June, and the next day acknowledged Hooker's letters saying "I cannot think now on the subject, but soon will." That night he read the letters, and to meet Hooker's request, though "quite prostrated", got his servant to deliver Wallace's essay, the letter to Asa Gray and "my sketch of 1844 solely that you may see by your own handwriting that you did read it". He left matters in the hands of Lyell and Hooker, writing "Do not waste much time. It is miserable in me to care at all about priority."
Lyell and Hooker agreed on a joint paper to be presented at the Linnean Society – Lyell, Hooker and Darwin were all fellows of the society and council members, and Hooker had been closely involved in reviving the fortunes of the society and running its journal. Other venues were either inappropriate, or in the case of the Zoological Society of London, potentially hostile under the leadership of Richard Owen. It was now time for the summer break but, as they knew, its meeting had been postponed due to the death of former president Robert Brown on 10 June 1858, and the Council had arranged an extra meeting on 1 July.
At the last minute, late in the evening of 30 June, Lyell and Hooker forwarded the Wallace and Darwin papers to the Secretary John Joseph Bennett, to be read at the meeting the next day. Mrs. Hooker had spent the afternoon copying out extracts from the handwritten documents Darwin had sent with his letter of the previous night, presumably chosen by Hooker to suit the verbal presentation, and Lyell and Hooker wrote a short introductory letter. The papers entitled respectively On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection, incorporated Wallace's pages; and extracts from Darwin's 1844 Essay and his 1857 letter to Gray. At the meeting the Secretary read the papers out, before going on to six other papers, and there was no discussion of them at the end of the meeting, perhaps because of the amount of business that had been dealt with including an obituary notice for Robert Brown given by Lyell, or possibly due to reluctance to speak out against a theory supported by the eminent Lyell and Hooker. Thomas Bell, who had written up the description of Darwin's reptile specimens from the Beagle expedition, presided over the meeting. He apparently disapproved, and in his annual presidential report presented in May 1859 wrote that "The year which has passed has not, indeed, been marked by any of those striking discoveries which at once revolutionize, so to speak, the department of science on which they bear". However, the Vice-President promptly removed all references to immutability from his own paper which was awaiting publication.
As might be expected, the joint paper alerted those subscribers who met the argument for the first time in print, and whose minds were prepared by prior struggles with the species question. Alfred Newton, who held the chair in Zoology and Comparative Anatomy at Cambridge from 1866 to 1907, wrote this: "I sat up late that night to read it [the Linnean Society paper]; and never shall I forget the impression it made upon me. Herein was contained a perfectly simple solution of all the difficulties which had been troubling me for months past. I hardly know whether I at first felt more vexed at the solution not having occurred to me than pleased that it had been found at all" (he was not alone in that thought!—see T.H. Huxley). Newton remained a Darwinian for the rest of his life. (Wollaston 1921 p112; see also Newton 1888)
While the meeting took place, Darwin was attending his son's funeral. His family moved to his sister-in-law's in Sussex to escape the fever, which eventually killed six children in the village of Downe. It had been a frightening and miserable fortnight, but he was "more than satisfied" with the outcome of the meeting. He then took his children to the seaside at the Isle of Wight and pushed ahead with an "abstract" of Natural Selection which again began growing to book size. He returned to the Moor Park spa with stomach ailments.
Wallace's reaction, delivered in January 1859, was that he was gratified to have spurred Darwin into making the announcement and that it would have caused him "much pain & regret" if his papers had been published on their own, without Darwin's papers. Darwin was still sensitive on the point, and assured Wallace that he "had absolutely nothing whatever to do with leading Lyell and Hooker to what they thought was a fair course of action". He responded to Wallace's enquiry about what Lyell thought of the theory by saying that "I think he is somewhat staggered, but does not give in and speaks with horror [of] what a job it would be for the next edition of "The Principles" [of Geology] if he were "perverted". But he is most candid and honest, and I think he will end up by being "perverted"." Lyell was still struggling to come to terms with the idea of mankind, with immortal soul, originating from animals, but "Considering his age, his former views and position in society, I think his conduct has been heroic on the subject."
Darwin was now working hard on an "abstract" trimmed from his Natural Selection, writing much of it from memory. The chapters were sent to Hooker for correcting as they were completed, which led to a minor disaster when a large bundle was put by accident into the drawer Hooker's wife used to keep paper for the children to draw on. Lyell made arrangements with the publisher John Murray, who had brought out the second edition of The Voyage of the Beagle. Darwin fretted, asking "Does he know all the subject of the book?", and saying that to avoid being more "un-orthodox than the subject makes inevitable" he did not discuss the origin of man, or bring in any discussion about Genesis. Unusually, Murray agreed to publish the manuscript sight unseen, and to pay Darwin two-thirds of the net proceeds. He anticipated printing 500 copies.
Darwin had decided to call his book An Abstract of an Essay on the Origin of Species and Varieties through Natural Selection, but with Murray's persuasion it was eventually reduced to the snappier On the Origin of Species through Natural Selection. The full title reads On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, with races referring to varieties of domestic and wild organisms and not to human groups.
By the end of May, Darwin's health had failed again, but after a week's hydrotherapy he was able to start correcting the proofs. He struggled on despite rarely being able to write free of stomach pains for more than twenty minutes at a stretch, and made drastic revisions which left Murray with a huge £72 bill for corrections. Murray upped the print run to 1,250 copies, with a publication date in November. A copy was sent to Lyell, with a "foolishly anxious" Darwin hoping that he would "come round". An eager Lyell gave Darwin "very great kudos", though he was still concerned that "the dignity of man is at stake". One of Lyell's relatives commented that it was "sure to be very curious and important... however mortifying it may be to think that our remote ancestors were jelly fishes". Darwin was "sorry to say that I have no 'consolatory view' on the dignity of man. I am content that man will probably advance, and care not much whether we are looked at as mere savages in a remotely distant future."
On 1 October Darwin finished the proofs, suffering from fits of vomiting. He then went off for a two month stay at Ilkley Wells House, a spa in the town of Ilkley. He was joined by his family for a time of "frozen misery" in the unusually early winter. Darwin wrote "I have been very bad lately, having had an awful 'crisis' one leg swelled like elephantiasis – eyes almost closed up – covered with a rash & fiery Boils; but they tell me it will surely do me much good – it was like living in Hell." On 2 November he was pleased to receive from Murray a specimen copy bound in royal green cloth, price fifteen shillings. Nine days later, still at the spa, he wrote notes to go with the complimentary copies, disarmingly anticipating their reactions: to Asa Gray "there are very many serious difficulties", to the Revd. John Stevens Henslow "I fear you will not approve of your pupil", to Louis Agassiz "[not sent in] a spirit of defiance or bravado" and to Richard Owen "it will seem 'an abomination'.", amongst others. For Wallace's copy he wrote "God knows what the public will think".
This was only the start of controversy and reaction to his book.
See the reaction to Darwin's theory for these developments, in the context of his life, work and outside influences at the time.