192 evolution: the ages and tomorrow 



isms, but that does not mean that man need submit to this 

 bUnd process now that he has an awareness of it. Surely, we 

 are justified in the feehng that the evolution of intelligence 

 is for the use of the organism finally possessing it, just as is 

 any other adaptive trait. 



Man's societies were long ago involved in overpopulation 

 when his early civilizations were finally established, since, 

 by the more efficient economy, they encouraged an in- 

 creased birth rate at the same time that the death rate was 

 decreased as peace and order emerged out of chaos. Empires 

 arose, humans multiplied, territories became too crowded, 

 rulers and peoples of the favored class were too stupidly 

 selfish and extravagant, and the struggle was renewed and 

 renewed again. To escape overpopulation and the conse- 

 quent economic impasse, peoples migrated, forming new 

 colonies until over the whole earth there was hardly a spot 

 without its colony. The multiplication of man was intensi- 

 fied, and the man-to-man struggle was intensified, and his 

 problems became more and more complex, and the end is 

 not yet in sight. Now, as overpopulation threatens him as 

 never before, man has nowhere to run; he must face it. 



Just prior to the advent of civilization there were prob- 

 ably not more than 15,000,000 humans in the world; four 

 thousand years later at the time of Christ there were possibly 

 150,000,000; by the year a.d. 1000 about 350,000,000; and 

 now less than 50 years short of a.d. 2000 there are near 

 2,500,000,000 people in the world. At the present moment 

 the rate is increasing so that this evening there are 70,000 

 more people in the world than there were yesterday eve- 

 ning, some 25,000,000 or more every year. Simple arithmetic 

 wdll show that at this rate there will be 5,500,000,000 people 

 in the world one hundred years from now; 14,000,000,000 

 two hundred years from now; and the staggering total of 

 over 44,000,060,000 in three hundred years.* Obviously, 



* The figures of future numbers of human individuals used in this 

 chapter are from population estimates of various authorities as of about 



