Show Me the Evidence!

Let's suppose you were a scientist and you were looking for reasonable evidence for a mechanism you had suggested for how a toad turned into a prince. What sort of evidence would you demand? Kevin Swanson would like a few hundred thousand transitional forms in the fossil record for starters. A little laboratory evidence for "punctuated equilibrium" might also be helpful, if that's the real mechanism that advanced the complexity of the life forms. Is it wrong to demand evidence, before we take a dogmatic stand on species evolution?