after the violent conditions that erm we think occurred in the early life of the earth and injected energy and churned up the atmosphere and formed the prebiotic molecules, we find that just those same molecules are actually in the clouds in space, and these clouds are the basic raw material from which stars and plants form in the first place, so we might ask the question could they have got into the earth's atmosphere without this intermediate process, and i think there are mechanisms whereby these molecules can accrete into the earth's atmosphere, and it certainly suggests that we should look at thse and certainly not be taken as a foregone conclusion that the uray/miller experiments are the only mechanism whereby the prebiotic soup was formed.