. Aspects of the origin of life. Life; Biochemistry; Biochemistry; Biogenesis. 156 J. D. BERNAL have claimed to demonstrate by mathematical arguments that even such a small part of organized nature as a molecule of ribonucleic acid would, if it had to come together by chance from a congeries of atoms, take almost infinitely more time than the presumed age of the universe. I know Professor Haldane [i] has argued that a very unHkely thing is not an impossible thing and that the chance origin of Ufe cannot be altogether neglected, but most of those bringing forward such argimients use them in a p
. Aspects of the origin of life. Life; Biochemistry; Biochemistry; Biogenesis. 156 J. D. BERNAL have claimed to demonstrate by mathematical arguments that even such a small part of organized nature as a molecule of ribonucleic acid would, if it had to come together by chance from a congeries of atoms, take almost infinitely more time than the presumed age of the universe. I know Professor Haldane [i] has argued that a very unHkely thing is not an impossible thing and that the chance origin of Ufe cannot be altogether neglected, but most of those bringing forward such argimients use them in a purely negative sense. If life could not have come together by pure chance, they argue, then its presence is either an illusion or that life was created and guided at every step by an intelhgent agent or at least by a teleological seeking for perfection. I do not want here to enter into these argu- ments, which are more philosophical than scientific, but I do want to make the point that the problem has been wrongly posed. There is no question, to anyone who has examined the evidence, of the need to explain the origin of life as con- sisting of one decisive step, because it plainly did not originate as such. Even. Fig. I. Formal scheme of five orders of a sequence of inscribed circles. Each unit contains three of the order beneath it. if we carmot as yet precisely determine the stages of biopoesis, their general character is already apparent, as I have attempted to sketch in my other contri- bution. Over and above any hypothesis of stages in time, we have before us in biochemistry and ultra-cytology concrete evidence of a series of grades of struc- ture of increasing complexity. The structures that we observe or study are not arranged in a continuous order but a discontinuous one. Each type of structure seems to be composed of units of fairly definite sizes which come together to form another unit on the next level (Fig. i). Take for example a vertebrate striated-muscle cell or f
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