chinglu You seem to be laboring under the misunderstanding that life is, at it's simplest, different from chemistry. It is not. Definitions of life come in more or less simple forms but it's really an arbitrary line drawn by various individuals at different points on the continuum of simple chemistry to complex lifeforms. At it's simplest life is a molecule able to assemble copies of itself from free chemical compounds in it's environment AND NOTHING MORE! The Last Universal Common Ancestor was far along in comparison and probably separated in time by 100s of millions if not billions of years. Nor was it likely the first form of life to do all the things you think it should, it was just the one lucky enough in the evolutionary crap shoot to survive and have progeny that survived all the way to us. I'm really having difficulty in understanding what your point is. LUCA existed, deal with the implications. GrumpyPlease Register or Log in to view the hidden image!