On the Origin of Species the publication of "On the Origin of Species" and the bicentenary of Darwin's birth were scheduled for 2009. They celebrated the ideas which "over the last 150 years have revolutionised our understanding of nature and our place within it". In a survey conducted by a group of academic booksellers, publishers and librarians in advance of Academic Book Week in the United Kingdom, "On the Origin of Species" was voted the most influential academic book ever written. It was hailed as "the supreme demonstration of why academic books matter" and "a book which has changed the way we think about everything".
On the Origin of Species correspondence with Joseph Dalton Hooker affirmed that he did not want to expose his ideas to review by an editor as would have been required to publish in an academic journal. He began a "sketch" account on 14 May 1856, and by July had decided to produce a full technical treatise on species as his "big book" on "Natural Selection". His theory including the principle of divergence was complete by 5 September 1857 when he sent Asa Gray a brief but detailed abstract of his ideas. Darwin was hard at work on the manuscript for his "big book" on "Natural