Secrets of the Sixth Edition: Darwin Discredits His Own Theory by Randall Hedtke argues that Charles Darwin's final 1872 edition of On the Origin of Species contains fatal flaws and admissions that undermine his own theory of evolution. Hedtke claims Darwin abandoned key mechanisms of his theory, challenging modern evolutionary teachings. Secrets of the Sixth Edition aims to prove that by the end of his life, Darwin was aware that his arguments lacked conclusive proof, making the 6th edition a record of the theory's potential failure rather than its completion.