Well, actually there is a highly respected theory (of which a scientist called Lynn Margulies is the chief exponent, I think)which says that all multicellular life is made up of unicellular life (eg. bacteria). But you're probably not interested in that because you 'know' everything there is to know already. And I bet you're just itching to send the 'thought police' round to deal with a heretic, like me, aren't you?