Some jokes were not created by anyone – that they evolved

"In the classic 1956 science-fiction story ‘Jokester’, by Isaac Asimov, the main character is a scientist studying jokes. He finds that, although most people do sometimes make witty remarks that are original, they never invent what he considers to be a fully fledged joke: a story with a plot and a punchline that causes listeners to laugh. Whenever they tell such a joke, they are merely repeating one that they have heard from someone else. So, where do jokes come from originally? Who creates them? The fictional answer given in ‘Jokester’ is far-fetched and need not concern us here. But the premise of the story is not so absurd: it really is plausible that some jokes were not created by anyone – that they evolved."