ORIGIN OF SELF-REPRODUCING SYSTEMS 359 



arose a special kind of competition among the drops, based 

 on the speed with which reactions were accomplished within 

 them and the rate of their growth. For this reason the prin- 

 ciple of the greatest speed (which must, nevertheless, be 

 compatible with the existence of the stationary system as 

 such) was a very important factor in the directed evolution 

 of organised formations. 



The origin of systems capable of 

 reproducing themselves. 



It must, however, be pointed out that the capacity for 

 self-preservation, and even for rapid growth, of the whole 

 dynamic system did not imply the complete immutability 

 of the system. On the contrary, the stationary drop of a 

 coacervate, or any other open system, may be preserved as a 

 whole for a certain time while changing continually in regard 

 to both its composition and the network of processes taking 

 place within it, always assuming that these changes do not 

 disturb its dynamic stability. 



Changes of this sort were, in fact, a necessary part of the 

 process of the emergence of life for they guaranteed the 

 evolution of the initial systems. Without these changes no 

 new material would have been provided for selection and the 

 further development of the systems would have been frozen 

 and brought to a standstill at some point. 



Naturally, it was of the utmost importance that these 

 changes should not overstep the bounds of the dynamic sta- 

 bility of the systems. Otherwise any markedly unstable com- 

 pounds which arose w^ould be in constant danger of passing 

 out of equilibrium and disappearing. Therefore, when there 

 was rapid and massive growth of the original systems, selection 

 took place, the only ones ^vhich were preserved for further 

 evolution being those in which the network of reactions was 

 so co-ordinated that there arose stationary chains of reactions 

 which were constantly repeated or, even better, closed cycles 

 of reactions* in which the reactions always followed the same 



* Of course these cycles must not, as we have already mentioned in Chapter 

 VII, be confused with the elementary cycles of chain reactions. — Author. 



