<P> The term monkey's uncle, most notably seen in the idiom "(well) I'll be a monkey's uncle", is used to express complete surprise, amazement or disbelief . It can also be used to acknowledge the impossibility of a situation, in the same way that "pigs might fly" is used . An example is if one says: "I may agree that if two plus two equals five, then I am a monkey's uncle". "I'll be a monkey's uncle" has been said to date from after 1925, the date of the widely publicized Scopes Trial in the United States, where the term first appears . The Oxford English Dictionary's earliest example is the phrase If that's a joke I'm a monkey's uncle, from an Ohio newspaper on 8 February 1925 . It was originally a sarcastic remark made by creationists . The notion "that (people) were descended from apes was considered blasphemous...by Darwin's contemporaries", and it was for this reason that the sarcastic phrase came into use . </P> <P> Michael Quinion notes that the phrase Monkey's uncle occurs in a parody of Longfellow's The Song of Hiawatha which was reprinted in James Parton's The Humorous Poetry of the English Language, published in 1881, and observes This may be just an accident of invention, but the date fits . Monkey's Uncle is the name of a song by the Selecter on their album Reel to Real criticizing religious dogma that contradicts scientific evidence . </P>

Where does the phrase monkey's uncle come from