MAN 477 



species increases to a maximum, — numerically and in vigor, — 

 wanes, and disappears. In a similar way genera and families 

 rise and decline. There is nothing to indicate that the present 

 species of plants and animals are to be exceptions to this rule. 

 They too will become extinct by actually dying out and by 

 replacement by other types, or will so change as to become new 

 species, differing in some definite and significant way from the 

 old. 



Man can readily adjust himself to these gradual changes in the 

 species about us if he can only insure that the new species which 

 replace the old shall be as well suited to his needs as the former 

 were. But what of man himself? Is our own species any 

 exception to this rule of change ? We have no evidence that it 

 is. Indeed the best students of the subject hold that the species of 

 the genus Homo have already changed several times since the genus 

 first appeared. This does not mean that man ever died out and 

 then reappeared; but that changes in our ancestors have been 

 important enough to make a succession of species of Man. 



Nevertheless man has undoubtedly introduced some new 

 factors into the problem of his own evolution. For example, he 

 makes, uses and improves tools for the better doing of his work, 

 and has built up a complex industrial and economic system about 

 this fact. He has gained power to modify and to use his 

 surroundings as no other animal has ;, he can compare, and dis- 

 criminate, and reason, and can preserve and convey his con- 

 clusions by means of the spoken and written language he has 

 invented, and can thus educate as no other species can. He has 

 organized his home and developed a spirit in his family life more 

 far reaching than is found elsewhere. He has built up a philos- 

 ophy of life, whether we call it science or religion, which enables 

 him to prophecy and to purpose for the future on the basis of 

 experience and faith. And upon all this he has superimposed 

 a complex competitive-political-economic-social organization 

 which helps or hinders the rest. By all of this he roughly 

 measures his civilization. The student of zoology will not 

 gain all that his course should give him if he does not properly 

 connect all these high human attainments with the life proc- 

 esses he has been studying among the animals. 



