Cancer proves evolution only insofar as one forgets, or pretends not to know, what evolution is supposed to explain.
The giraffe is one of those all-star icons of evolution, familiar from textbook covers, that falls apart on closer inspection.
Any appeal to accidental processes to accomplish an unbelievable coincidence is really just an appeal to unbelievable coincidence.
Leisola, of course, is a Finnish bioengineer who realized through his work that life could not have assembled itself through unguided processes.
The changes involved in adapting a generic mammalian template into a whale are certainly not all simple, independent, single-letter changes.