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,
Evolution of the brain evolution once the divergence between chimpanzees and humans had already occurred. Each of the gene sequences went through specific changes that led to the evolution of humans from ancestral relatives. In order to determine these alterations, Lahn and his colleagues used DNA sequences from multiple primates then compared and contrasted the sequences with those of humans. Following this step, the researchers statistically analyzed the key differences between the primate and human DNA to come to the conclusion, that the differences were due to natural selection. The changes in DNA sequences of these genes accumulated to bring about a competitive advantage