The Origin of Life 13 



Oparin suggests that, in a sensp, coacervate droplets competed 

 with each other for materials-that some, which by chance had a 

 favorable composition or internal configuration, grew more rapidly 

 than others. These successful droplets were then first to reach a size 

 at which they became unstable and broke apart into smaller par- 

 ticles. These then enlarged, subsequently divided, and thus con- 

 tinued the sequence. One can also imagine that accidental fusion 

 of droplets might have carried them beyond the stability point, 

 causing breakdown into smaller units. Should the droplets have dif- 

 ferent compositions, a sort of protosexual recombination process 

 would occur. Thus one can see in coacervates many properties that 

 would qualify them as hnks in a chain leading to the structure of 

 life as now knowTi, and, since the matter carries on the function, to 

 living systems of the familiar sort. They are clearlv separated from 

 their environment, have internal structuring, absorb matter from 

 their environment, and have sufficient multiplication and "recombi- 

 nation" to permit the operation of natural selection. 



It seems clear that, in the vast stretches of geologic time, mech- 

 anisms such as those outlined above (and others as vet undiscov- 

 ered) produced the ancestors of the hving systems we know todav. 

 Indeed, when one pictures the vast oceans, lakes, and hot springs 

 rich in organic compounds and presenting a wide variety of con- 

 ditions of temperature, light, salt concentration, and phvsical sub- 

 strate (crystals, clavs), it is difficult not to believe that living sys- 

 tems developed more than once. It is not unlikely that modern 

 organisms are the descendants of the victor in a fierce energy war 

 among the early "organisms." 



ORIGIN OF THE GENETIC CODE 



The level of complexity of the hypothetical ancestral organism dis- 

 cussed to this point does not involve a system by means of which the 

 entity could be replicated as a unit. Splitting by fission may or may 

 not result in the formation of equal parts; in fact, it might be 

 imagined that occasionally one of the parts would lack a component 

 essential for the maintenance of life. At this stage there was no sys- 

 tem of heredity, no genetics, which would ensure the continued 

 production of functional entities. The first principle of genetics is 

 "like begets like." This is not the result of a great immutable "law 

 of nature" but rather the functioning of a complex system for trans- 

 mitting genetic "information," the information needed to construct 

 a new organism. Without such a system, it seems certain that life 

 would not have evolved beyond the level of coacervate droplets. 



