Well it is a question that I did mull over a bit but came to the conclusion that if I barred evolutions then people might not actually nominate anything at all. The only thing I would say is the greater the contrast between point A and if not B then C or D, the better. If there's a WTF moment like last years Andre 3000 album then all the better.
Evolutions are interesting though in that sometimes, in hindsight, you can hear the seeds of the latter incarnations in early stuff. Example being when you really listen, I'm not sure we should be that surprised where Depeche Mode ended up compared to where they started.
Depeche Mode are one that came to mind. Funnily enough, Radiohead surely need a mention here as well. U2 have had a habit of trying things out. Then there are drastic departures, like No Doubt ditching ska-punk after someone getting Gwen a make-up kit for Christmas and convincing her she was pretty enough to be a manufactured pop star. Taylor Swift tried to go back from pop diva to more 'americana' roots at one point. I've got a few more which I might save for if I nominate them. But there is probably a wider range than people will immediately think.