EVOLUTION AND HUMAN DESTINY 



individual of the herd, permitting better signaling and 

 better response to signals would favor the probability 

 of survival of such an individual. This being true, such 

 a mutant change will gradually become one of the char- 

 acteristics of the species. On the basis of many such 

 mutant changes the gradual acquisition by man of the 

 necessary nervous and organic equipment for language 

 can be explained. A similar argument can be employed 

 to explain the development of man's highly developed 

 central nervous system. (Also the use of his hands.) 



But as has been discussed, biological makeup is not 

 the sole key to man's language. Neither is his more 

 highly developed nervous system by itself sufficient to 

 account adequately for human achievement. When the 

 ratio of brain development in man, to that in the 

 higher animals, is compared with corresponding ratio 

 of their mental achievements, one finds that man's ac- 

 complishments seem vastly out of proportion. How 

 then is one to explain that man's ability is so very much 

 greater than what one would expect on the basis of his 

 brain development alone, basing the comparison on 

 animal standards? 



When the nature of man's evident ability is analyzed, 

 one can hardly fail to recognize that much of it is based 

 on learning in its broadest sense. Now it is true of 

 course that animals also learn. But their learning takes 

 place in a far more limited manner. Animal learning 

 is based upon observation by the individual animal 



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