Question: where does the term monkey's uncle come from

title: Monkey's uncle
text: 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 .