[UCANSEE2]

Of course no species suddenly mutates to another, so far as we know.

There are 'plants' on the ocean floor that pull up their roots, turn into a fishlike creature and swim away.

A caterpillar turns into a butterfly (metamorphosis- which is a way of saying it completely changes it's entire bodily structure).

[BroJoeK]

UCANSEE2: "There are 'plants' on the ocean floor that pull up their roots, turn into a fishlike creature and swim away."

Sure, and if they are examined carefully, including their DNA, they will quickly reveal their true nature, whether plants, animals or something else.

UCANSEE2: "A caterpillar turns into a butterfly (metamorphosis- which is a way of saying it completely changes it's entire bodily structure)."

Of course, but once conceived, its DNA inheritance doesn't changes, and can tell us what the creature really is, plus how closely related to every other life form.