Au contraire Dr. Ben, it's done all the time... by renaming or reclassifying them.
Taxonomy is a mess these days, as computer models positing what "evolved" from what rule the day as to which plants or fungi are related. In the process, keeping track of it all is very expensive for users and less applicable to the organisms in question. Over the last fifteen years, perhaps 10% of the species on my property have had name changes. It's really annoying.
Evolution is a theory. Nothing more.
Carson is correct, but obviously there is some mechanism that creates more complex life for simpler life. Now what that mechanism is no one knows.