ZOOGENESIS 



quite a different way. He also has become very deli- 

 cately adjusted to his environment. But in the case 

 of man this has been an asset instead of a liability as 

 it is with the great apes. Man has been able to over- 

 come the increasingly delicate adjustment to his en- 

 vironment by artificially creating for himself a special 

 environment in which he lives more or less completely 

 independent of his natural environment. For the 

 most part man grows his food and the materials to 

 make his clothing and other necessities, and he con- 

 trols the temperature in which he lives. Thus the 

 Esquimaux actually exist in a tropical temperature no 

 matter how low the temperature outside of their 

 thick clothing and their heated igloos may be. 



As man and the man-like apes are both very highly 

 specialized, but are specialized in widely different 

 directions, we cannot suppose that either descended 

 from the other, or indeed that there really is any very 

 close relationship between them. The truth of this is 

 now very generally admitted by biologists. 



Professor Henry Fairfield Osborn has pointed out 

 that while nature may transform an organ through 

 change of function, it can never restore a single lost 

 part, whether it be a lost tooth, a lost digit, a lost 

 ankle bone or rib, a lost tendon, or a lost nerve. The 

 evolution of anatomical or structural organs is never 

 reversible. By the application of this principle he 

 pointed out that the human hand could never have 

 reacquired the nerves, muscles, functions, freedom, 

 flexibility and separate innervation lost in the highly 

 specialized hand of the arboreal, or tree-living, apes. 



[2-2.5] 



