On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection Letter" from Darwin to Asa Gray. This was the first announcement of the Darwin – Wallace theory of evolution by natural selection; the papers 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". 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
Reactions to On the Origin of Species breeding that would eventually form part of "The Variation of Animals and Plants under Domestication". He wrote to Asa Gray and used the example of fantail pigeons to argue against Gray's belief "that variation has been led along certain beneficial lines", with the implication of Creationism rather than Natural Selection. Over the winter he organised a third edition of the "Origin", adding an introductory historical sketch. Asa Gray had published three supportive articles in the "Atlantic Monthly". Darwin persuaded Gray to publish them as a pamphlet, and was delighted when Gray came up with the title of "Natural Selection Not