The Selfish Gene was dropped. The book contains no illustrations. The book has been translated into at least 23 languages including Arabic, Thai and Turkish. In 2006, a 30th-anniversary edition was published with the Trivers foreword and a new introduction by the author. It was accompanied by a "festschrift" entitled "" (2006). In March 2006, a special event entitled "The Selfish Gene": Thirty Years On was held at the London School of Economics. In March 2011, Audible Inc published an audiobook edition narrated by Richard Dawkins and Lalla Ward. In 2016, Oxford University Press published a 40th anniversary edition with a new epilogue,
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