CATALYSIS AS THE EFFICIENT CAUSE OF EVOLUTION 255 



What heritable catalyst changes are effective in evolution? 

 The answer here must be, Only those which persist and give a 

 biont (plant or animal) some heritable advantage over com- 

 petitors in the struggle for life, under the conditions existing at 

 the time and place at which the particular heritable catalyst 

 change occurs. Many catalyst changes are lethal, or else produce 

 sterility or low rate of reproduction; others are of no evolutionary 

 importance. Many bionts possessing promising heritable catalyst 

 changes may succumb to the perils of surrounding conditions, and 

 only the survivors among these advantageous changes live and 

 establish clones or families, which may then become factors in 

 evolution at higher organizational levels where the struggle for 

 existence is visibly waged. 



The case of ascorbic acid (vitamin C) is in point. Many animals 

 (dogs, cats, rats, fowls, rabbits) can synthesize this antiscorbutic, 

 factor, and do not develop scurvy if it is missing in their diet; and 

 they can survive the long winter when natural greens are scarce 

 or lacking. But monkeys and guinea pigs readily develop scurvy 

 if deprived of ascorbic acid, and A. Szent Gyorgyi (Nobel prize, 

 1937) comments 16 that these two experimental animals "come 

 from the ever-green tropical surroundings where there is green 

 food (which contains ascorbic acid) all year round. One of the 

 basic laws of Nature is laziness; Nature will not do unnecessary 

 things, and if a species has no need to make ascorbic acid, it will 

 not make it; it will forget, or never learn to make it. The rabbit 

 cannot permit itself to do this, for it would die during the long 

 winter in our moderate climate." Obviously if an animal's 

 catalysts cannot synthesize ascorbic acid and this is essential to its 

 life, the animal in nature is limited to areas where adequate 

 vitamin C is found in foods naturally available. The habitat of 

 such an animal could be greatly extended if it became independent 

 of dietary ascorbic acid. This could happen in a variety of ways; 

 by a gene mutation; by acquisition of a messmate or symbiont 

 which can produce it (as is the case with many ruminants*); or by 

 developing catalysts that can synthesize it. 



The notion that all heritable change must be genie may sterilize 

 thought, but will not affect nature. Dr. Francis B. Sumner 17 

 states: "It seems obvious that any one who sponsors a theory of 

 evolution by large steps must provide an agency through which 

 functionally related parts are brought to vary together in such a 



* Cf. the case of the termite and of the lichen (see Index). 



