EVOLUTION AND HUMAN DESTINY 



serve as stimulatory or inhibitory agents affecting other 

 groups of specialized cells. A few cells did as a matter 

 of fact remain relatively unaltered from their original 

 individual status. An example of this are the protozoa- 

 like white blood corpuscles, which have the specific 

 function of destroying such alien protozoan invaders as 

 the organism may at times be plagued with. Still other 

 cells became part of the digestive system — the circula- 

 tory system — were designated to carry compounds 

 needed for the metabolism of all the cells, store food 

 products, or became components of the increasingly 

 complex reproductive system. 



It is not surprising that such a process of develop- 

 ment must have taken considerable time. Thousands 

 of millions of generations of living creatures were born, 

 reproduced and died during this process. The only 

 driving force of the entire development that is pres- 

 ently known to us is the mutation of genetic material 

 and the survival or rejection of these chance mutations. 

 The determining factor in the survival of these muta- 

 tions is their ability to function in relation to a given 

 environment, especially in respect to their ability to 

 give rise to a maximum number of surviving offspring. 

 Mathematical analysis shows that even relatively small 

 advantages of one mutant over the norm would, given 

 a sufficiently large number of generations, account for 

 a much greater abundance of the mutant individuals. 

 The ever-changing environment on the earth's surface 



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