HUMAN LIFE 



to the future course of human evolu- 

 tion? 



As Conklin has pointed out, progressive 

 evolution of special lines of animals and 

 plants has limits fixed by its very nature. 

 Evolutionary progress of animal bodies 

 means specialization of the structure and 

 functions of these bodies. Specialization, 

 as we have indicated earlier in this dis- 

 cussion, means closer adaptation to a 

 certain set of conditions of life but also 

 means surrender of general adaptability. 

 If an animal has given up legs for the 

 sake of having flippers or wings or hands, 

 it has acquired a more specific use of its 

 limbs at the expense of a more general use 

 of them. Now man has gone a long, long 

 way in the progressive evolution of his 

 body and its functions. But it is appar- 

 ently true, as Conklin has said, that for 

 ten thousand years there has been no 

 notable progress in this evolution. If 

 evolution is carrying man forward 

 and we do not doubt it it is doing it in a 

 different way. This way seems to be the 

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