Man in the Light of Evolution 



start, point forward to the higher mental and 

 moral powers of a distant future. 



But very few vertebrates attained these higher 

 stages and powers. The fish stayed in the water, 

 and not a few amphibians have returned to the 

 life of their fish ancestors. Reptiles remained 

 cold-blooded. 



The bird developed a very high temperature 

 of body, marvelous locomotive power, and the 

 keenest sense organs. But in brain it has re- 

 mained far inferior to the plodding mammal. 

 Perhaps its power of flight kept it largely out of 

 reach of its enemies. The hunted mammal be- 

 came wary and shrewd. 



The highest development of the brain was ap- 

 parently correlated with the origin and use of 

 the hand and fingers, and the hand was the re- 

 sult of arboreal life. But most mammals re- 

 mained on the ground, and thus cut themselves 

 off from the possibility of attaining the very 

 highest stage. 



It is evident that we must distinguish very 

 sharply between fitness and dominance. The 

 dominant forms, like paleozoic mollusks and 

 mesozoic reptiles, are those which are reaping 

 to the full the benefits of the use of some power 



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