A disproof, or anti-proof, is a well-reasoned counter-argument against a strongly-asserted claim. Disproofs are possible in the not-so-unlikely case that someone has over-looked an implicit (and false) assumption. For example, creationists argue that the kangaroo, the snake, and the papaya disprove the theory of evolution, while some argue[Who says?] that volcanoes disprove global warming (both that it exists and that humans are the cause).