586 HUMAN BIOLOGY 



higher animals do, and therefore there is httle probabihty 

 that man will disappear and leave the lead to some other 

 type of animal. Already man controls his environment to 

 such an extent that it is almost inconceivable that his 

 race should be wiped out and leave other forms of hfe 

 persisting which are so much more the slaves of environment 

 than he is. 



There is no probabihty that the human race will ever 

 become perfect in body, mind or society; no doubt there will 

 always be room for improvement. There may be a reduction 

 in the relative amount of degeneracy, a decrease in the 

 numbers of the bungled and botched, the feebleminded and 

 insane, the antisocial and the brutal, but probably without 

 any prospect of ehminating all degeneracy. There may be 

 an increase in the relative number of really superior persons 

 until the general level may be more nearly that of the best 

 specimens of the present race, but there is no likehhood that 

 the entire race can be made illustrious or perfect. 



Possibly new mutations may occur that may lead to 

 the production of individuals superior to any that have 

 appeared hitherto, superior in physical vigor and length of 

 Hfe, in mental capacity and performance, in social and 

 moral quahties. But if such mutants should appear, they 

 would have to be preserved and perpetuated by intelligent 

 social selection rather than by natural selection, for man is no 

 longer the slave of his environment or the helpless victim of 

 circumstance. To a large extent he shapes his own environ- 

 ment and to that extent he controls his own destiny. 



Consequently great secular changes, such as changes 

 of climate, the coming of another ice age, the formation of 

 deserts, or the rising or falling of continents would never 

 again affect the human race as greatly as they did in the 

 past. Changes in climate might cause extensive migra- 

 tions, another ice age might make tropical resorts popular, 

 formation of deserts might necessitate extensive irrigation 

 projects, changes in the land and water areas of the globe 

 might necessitate extensive migrations but they would 

 probably not greatly change the human type, for man now is 

 able to control his environment rather than permit it to 

 control him. And the more he is able to control the condi- 



