198 evolution: the ages and tomorrow 



The literature on human populations shows the hopeless 

 dilemma in which people find themselves under excessive 

 crowding in such modem examples as India and China, and 

 striking instances on a smaller scale as Puerto Rico and 

 Japan. Puerto Rico, an island slightly larger than Long Is- 

 land, became a United States possession at the close of the 

 Spanish-American War. This onetime tropical paradise ly- 

 ing in the beautiful Caribbean Sea had long been exploited 

 ruthlessly by its Spanish conquerors. A mixed population 

 of descendants of negro slaves and Spanish whites had, at 

 the time of our war with Spain, become stabilized at about 

 1,000,000 people. Epidemics and acute food scarcity killed 

 most of the individuals in the population long before middle 

 age; in fact, the death rate was appalling, but it was more or 

 less evenly offset by a very high birth rate. Puerto Rico is 

 mountainous and less than half of its land is arable. At the 

 time the United States took charge the natives were prac- 

 ticing a destructive Latin-American agriculture, which is 

 to burn out a patch of jungle, get quick crops, and in a 

 matter of a year or two let the patch go back to jungle. 

 Increases in the population forced more frequent burnings 

 until now the magnificent forests of the island are gone and 

 the land has steadily deteriorated. At the end of the Span- 

 ish-American War the island was a shambles. Sanitation was 

 nonexistent, few schools were operating, and the population 

 was half-starved and had been so for years. 



The United States introduced sanitation, hygiene, and 

 medicine. The economy was reorganized around sugar cane 

 as the principal crop, and this was given practically an un- 

 limited tariff -free export market in the United States. Fruit 

 and rice and the usual garden vegetables, which are consumed 

 on the island, constitute the rest of the agriculture. The island 

 is still not industrialized to any real extent, and in the lim- 

 ited agricultural economy there is an income distribution to 

 about three-fourths of the Puerto Ricans of only $750 a 



