BIOLOGY AND HUMAN TRENDS — PEARL 337 



The social consequences of population growth, present a much 

 more subtle and' complicated problem than mere space or food. The 

 suggestion just made that the total land area of the globe might 

 be equally divided per head of population is an obviously fantastic 

 one, with only a sterile arithmetic meaning. Not all the land is 

 equally useful for sustaining human life either directly or indirectly. 

 Some of it is of no use whatever. And this brings us to the crux 

 of the population problem, which is that each unit of the popula- 

 tion must) somehow or other get its living. All other forms of life 

 except man get their living by one or the other or a combination of 

 two direct ways: These are (1) by preying upon other living things, 

 plant or animal ; or (2) directly converting inorganic materials into 

 living substance. Man today gets his living by indirect processes 

 conveniently labeled economic. He is in the main employed in 

 doing things that he can trade with somebody else for the biological 

 requisites for living. The population of the world has now become 

 so large, and the discoveries and applications of science have made 

 the producing of the things that can be traded so much easier than 

 it used to be, that great numbers of people all over the world find 

 themselves unable to get a living by this process that was formerly 

 so relatively simple. Thei rapid development of the industrial type 

 of civilization in the nineteenth century made the gloomy prophecies 

 of Malthus at its beginning look silly. The population grew at a 

 tremendous pace when he thought its growth would be checked by 

 want and misery. And people were having, by and large, a grand 

 time while their number was increasing; because they were experi- 

 encing the enormous improvements in the physical comforts of liv- 

 ing that came with the advance and applications of science. But 

 these very factors, plus the enhanced survival rate coincident with 

 the development of public health, cause the ugly spectre of unem- 

 ployment to rear itself higher and higher until it has now become 

 the most serious problem that humanity faces. 



It is to be noted at this point that in modem civilization, as a 

 normal consequence of the relation of individual man's biology to 

 his age, approximately 50 percent of all human beings have to earn 

 the livings not only of themselves but also the major part of that 

 of the other 60 percent. Man develops slowly. Children are in- 

 capable of earning their own livings before they are about 15 years 

 old, and have passed approximately a sixth of their total life span, 

 and between a third and a fourth of their average life duration. At 

 the other end of life, for the great majority of human beings over 

 60 years of age their living must come in whole or in considerable 

 part either from the efforts of the active workers between 16 and 

 50, or from what they themselves were able to save while they were 

 in their productively efficient ages. In practically all countries the 



