I'll be a monkey's uncle

Uncertain; the term monkey’s uncle appears in 19th-century works and may allude to early ideas about what is now called the theory of evolution. The term may then have gained more currency after the widely publicized 1925 Scopes Trial in Tennessee, United States, in which a high-school teacher was found guilty of having violated a law prohibiting the teaching of human evolution in a state-funded school.

• "Well I’ll be a monkey's uncle! I would never have thought that tourists would go into space!"
• ""Well, I'll be a monkey's uncle!" Lem said. "I've heerd of rifles with transits on 'em, but I ain't ever seen one. Mind if I look at her?""
• "Well, I'll be a monkey's uncle, I actually solved that one."
• "[...] I made as if to step inside—wham, bang, I'll be a monkey's uncle if he didn't slam the door in my face! What was I supposed to do now? It wasn't exactly a cheerful situation."
• "But I know I am better than that. I completed two and a half years at the M.J.C., and I'll be a monkey's uncle if I did it all just to be neglected in some backwoods, drafty, lo-tech, no-glory, never-been-remembered-for-all-the-great-things-I-do, dead end court wizard position."
• "Well, I'll be a monkey's uncle if it isn't my old pal, Captain Pete. I haven't seen you in years. Good to see you!"
• ""Well, I'll be a monkey's uncle. That's incredible and …" he was silent working it out, "and that means that I am actually the last of the McNaughtens and now live here in Weatherwood.["]"