I believe what Red was trying to say is that mutation can aid in natural selection and natural selection is what drives evolution. Is that what happened in this case? I don't know, ask Beaker and Dr. Bunsen.
I've never questioned this. That's why I clarified my post to say that I don't consider this proof that dolphins once walked on land. I've never even disputed the possibility that Dolphins may have walked on land. I just stated that I don't think this one Dolphin with extra fins "proves" that it happened. It could be just a genetic oddity. It could be the beginings of an evolution going forward. It may possibly be a remnant of a past evolution. We have no way of really knowing for sure, so to say it proves anything is stretching it a bit.
Proof of evolution & proving evolution are two seperate things. This may indeed be proof of evolution, but it certainly does not prove it.
it is entirely unnecessary to use new stuff to "prove" evolution. we are as sure of evolution as we are that the earth is orbiting around the sun.