Evolution never permits one thing to turn into another, fundamentally different sort of thing. All evolution is just a matter of incremental, superficial changes being slowly compiled atop various tiers of fundamental changes. Thus every new species, genus or higher taxa that ever evolved was just a modified version of whatever its ancestors were.
And those successive levels of similarity represent taxonomic clades which will forever encompass all the descendants of that clade to matter how different they eventually become.~ Ernst Walter Mayr (1904-07-05 2005-02-03 age:100)
Law of Monophyletic Variation
Why then does every creationist publicly proclaim the very opposite, that evolution is all about the creation of bizarre chimeras like crocoducks and spontaneous generation of new radically different lifeforms out of nothing? That is a straw man argument, otherwise known as lying about your opponent’s position to more easily ridicule it. The lie is an admission creationists have no truthful arguments against evolution. Even they know they have to lie to support creationism. Even they know creationism is false. They support it for ulterior motives, usually financial. The humour of it is the creationists are the ones who assert new species appeared out of nothing by magic. They are trying to tar evolutionists with their own absurd beliefs.