Well... as Tormod said... We all came from a certain little bacterium... or was it a protozoan? OH well... all i know is it was small and it was the only form of life on Earth at the time. Of course it makes you wonder... why is it not that every form of life is mobile? A plant is generally a form of life that doesnt move... well... thats not what a plant is, but plants dont usually move.
BUt why??? There are definite advantages to mobility so what caused evolution to decide to immobilize them... Overall i would say plants are far more self-sufficient than animals. But if they had mobility would they be less? Is that what we sacrificed for mobility? Self-sufficiency?
EIther way i dont think that we are much more up the evolution scale than plants. And i dont think that we evolved from plants either. Are there any plants that move? Other than a few in the ocean.
Oh by the way Biochemist. Nice burn lol...
In fact, we have present day examples of life forms that are difficult to assign to either the animal or plant kingdom. In the United states, we call those life forms "congressmen".