english: What happened was that Aveling's mistress was Marx's daughter, and when both Darwin and Marx were dead, Marx's papers became muddled up with Aveling's papers, and a letter from Darwin saying, "My dear sir, thank you very much but I don't want you to dedicate your book to me," was mistakenly supposed to be addressed to Marx, and that gave rise to this whole myth, which you've probably heard.
non_english: Čo sa naozaj stalo, bolo, že Avelingova žena bola Marxova dcéra a keď zomreli obaja, Marx aj Darwin, Marxove spisy sa zmiešali s Avelingovými a list od Darwina, v ktorom stálo: "Vážený pane, ďakujem veľmi pekne, ale nechcem, aby ste venovali svoju knihu mne," sa omylom považoval za adresovaný Marxovi, a tým vznikol tento celý mýtus, o ktorom ste pravdepodobne počuli.