I was not trying to imply that sharks had somehow avoided evolution (probably just could not be bothered to read Darwin's dense prose) ! Merely that if you are

I was not trying to imply that sharks had somehow avoided evolution (probably just could not be bothered to read Darwin's dense prose) ! Merely that if you are the perfect "fit" in size and shape etc already, evolution must focus on the more and more esoteric threats to your reproductive survival. Once you are basically swimming in a warm buffet, with nothing likely to be able to kill you one on one, evolutions pressures relax on the big obvious things and starts to focus on that liver. which seems to be pretty big even for a predator.