Darwin found an answer to the problem of how genera forked in an analogy with industrial ideas of division of
labour, with specialised varieties each finding their niche so that species could diverge. He experimented with seeds, testing
their ability to survive sea-water to transfer species to isolated islands, and bred pigeons to test his ideas of natural
selection being comparable to the "artificial selection" used by pigeon breeders.
In the spring of 1856, Lyell read a paper on the Introduction of species by Alfred Russel Wallace, a naturalist
working in Borneo. Lyell urged Darwin to publish his theory to establish precedence. Despite illness, Darwin began a 3-volume
book titled Natural Selection, getting specimens and information from naturalists including Wallace and Asa Gray. In December
1857 as Darwin worked on the book he received a letter from Wallace asking if it would delve into human origins. Sensitive
to Lyell's fears, 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." Darwin added that "I go much further than you."
His manuscript reached 250,000 words, then on 18 June 1858 he received a paper in which Wallace described the evolutionary
mechanism and requested him to send it on to Lyell. Darwin did so, shocked that he had been "forestalled". Though Wallace
had not asked for publication, Darwin offered to send it to any journal that Wallace chose. He put matters in the hands of
Lyell and Hooker. They agreed on a joint presentation at the Linnean Society on 1 July of On the Tendency of Species to form
Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection. Darwin's infant son died and he
was unable to attend.
The initial announcement of the theory gained little immediate attention. It was mentioned briefly in a few
small reviews, but to most people it seemed much the same as other varieties of evolutionary thought. For the next thirteen
months Darwin suffered from ill health and struggled to produce an abstract of his "big book on species". Receiving constant
encouragement from his scientific friends, Darwin finally finished his abstract and Lyell arranged to have it published by
John Murray. The title was agreed as On the Origin of Species by Means of Natural Selection, and when the book went on sale
to the trade on 22 November 1859, the stock of 1,250 copies was oversubscribed. At the time "Evolutionism" implied creation
without divine intervention, and Darwin avoided using the words "evolution" or "evolve", though the book ends by stating that
"endless forms most beautiful and most wonderful have been, and are being, evolved." The book only briefly alluded to the
idea that human beings, too, would evolve in the same way as other organisms. Darwin wrote in deliberate understatement that
"light will be thrown on the origin of man and his history."