BIOLOGICAL EVOLUTION 65 



change in the evolutionary process when natural selection turned 

 from the development of the organism to the development of 

 intellectual power, " for man is enabled through his mental 

 faculties * to keep with an unchanged body in harmony with the 

 changed universe.''' He invents weapons, tools, and various 

 stratagems, by which he procures food and defends himself. 

 When he migrates into a colder climate he uses clothes, builds 

 sheds, and makes fires.^ What a contrast this to that of the lower 

 animals, who " must have their bodily structure modified in order 

 to survive under greatly changed conditions." 



The development of intelligence and sagacity in earliest times 

 enabled the tribes whose members were best endowed to supplant 

 the other tribes, even as today in various parts of the world.^ 

 With the development of men in society, progress became more 

 rapid through imitation, reason and experience.' Likewise were 

 developed sympathy, fideHty, courage and obedience to authority. 

 " A tribe possessing the above qualities in a high degree would 

 spread and be victorious over the other tribes; but in the course 

 of time it would, judging from all past history, be in its turn 

 overcome by some other and still more highly-endowed tribe. 

 Thus the social and moral qualities would tend slowly to advance 

 and be diffused throughout the world."* 



From experience the value of co-operation was learned, habits 

 formed and sympathy developed, which after many generations 

 became fastened upon the organism as an instinct.^ Thus, too, 

 originated other social virtues such as the praise and blame of 

 fellow-men, love of approbation and dread of infamy, and remorse 

 at the consciousness of failure in the performance of duty. Later 

 the self-regarding virtues developed, such as temperance, chastity, 

 etc., based on experience of the results of conduct.^ 



As Darwin's argument concerning the working of the law of 

 natural selection among civilized nations is built so largely on the 

 labors of such investigators as W. R. Greg and Francis Galton, 

 we will pass over the subject for the present and turn to another 



^ Descent of Man, p. 152. ■* Ibid., p. 156. 



2 Ibid., p. 154. 5 Ibid., p. 157. 



3 Ibid., p. 155. 8 Ibid., p. 158. 



