Darwin is the hero of evolution because he observed about a dozen finches with different beak sizes ranging in the scale of micrometers. His imagination took him to wild speculations based on these observations. For example, the bear, with it's mouth open catching fish could "easily" have evolved from a whale that uses the same method to catch it's food or vice versa since scientists still can't decide whether whales evolved from land animals who were once sea dwelling animals who (for whatever reason) decided to flop out of the water & then (for whatever reason) venture back into the sea.

Science, for the record, is only observable, repeatable, testable. A theory is NOT science. No one has ever observed anything other than it's kind produce it's own kind. Variations within the kind can & do happen but only within the existing gene code. No animal has ever or can ever venture outside of the species line within it's own gene code. A hummingbird will never produce a vulture or vice versa or a banana. Cosmic, chemical, stellar, organic & macro evolution has never been observed. Cannot be repeated. And is not testable. That is not science. That's wishful thinking & imagination & great faith.