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THE REPLICATION OF SURFACE PATTERNS - AN 

 ALTERNATIVE ENTRY FOR LIFE 



The identification of the large biopolymers — proteins and 

 nucleic acids — as the significant agents in self-replication has been 

 the motif of most of this volume. The implication taken is plain — 

 the earliest examples of such a well-developed system as we see at 

 work universally in life today must have been in some way simpler 

 analogies of the two classes of substances. The essentially homoge- 

 neous nature of the self-replicating preparations of enzyme, energy 

 source, monomers, and template in water suspension has been seen as 

 an advanced version of the original natural system. That beginning 

 system would have been a simpler, less adapted set of much smaller 

 molecules in the same sort of solution where the chemistry is basi- 

 cally similar to that of the modern examples. 



It is clear that the inference, suggestive and powerful though it 

 is, is not unique. The gap in time allows the postulation of other dis- 

 tinct systems of entry that are discontinuous with the present infor- 

 mational but continuous in metabolic mechanisms, and which might 

 step by step have come to develop the powerful self-replication 

 that is universal today. For example, very recent experimental 

 support has been found for a suggestion, 15 years old or more, 

 that differs in most ways from the prototype of a linkage between 

 the two classes of polymers. This hypothesis suggests replicating 

 molecular patterns in two dimensions from a solid surface and not in 

 one dimension from a long helical polymer. It links an inorganic 

 substrate in an essential way with the organic product. It seems 

 prudent to recognize that neither of these two incomplete models is 

 apt to contain the whole story, but the whole domain of simple 

 models spans between them as extremes. Consideration for both of 

 the poles is surely the wisest strategy. In the next pages we present a 

 summary of the model that rests on an inorganic notion of the first 

 steps toward life. 



Monomer Supply and the Early Atmosphere 



The organic chemists view the decisive polymers as links of the 

 very common atoms, C, H, N, O, P, and S. The two essential heavier 



