Adaptation and Human A-ffairs 459 



from the paths of righteousness, or from the prescriptions 

 laid down. If, however, we adopt an evolutionary point 

 of view we discover that there is no absolute best way. We 

 have to test out each detail as we go along. Even the Dar- 

 winian implication of having arrived at our present status 

 by virtue of generations of survival does not assure us of 

 our fitness in any absolute sense, or of our own continuing 

 fitness. There are the many disharmonies of structure and 

 function which we have carried along with us through the 

 ages. There are new situations to which we shall need con- 

 stantly to adjust ourselves. We shall use, however, some 

 method more immediate and more reliable than the empirical 

 struggle for existence with the elimination of the faulty 

 guesses. 



In agriculture the principle of adaptation came to be 

 applied in the intensive study of the reactions of plants and 

 animals to the environment experimentally modified in one 

 detail after another. Just what is there in the soil that is 

 essential to plant growth? How can we get the maximum 

 of pork for a given quantity of raw material? Why do 

 sheep thrive better in one region than in another? How can 

 we combat liver flukes or cattle ticks? 



These and hundreds of other practical questions have 

 taken on a form that permits scientific attack just as fast 

 as we acquire the habit of thinking of the larger interrela- 

 tions of living things. That is to say, as fast as we assimilate 

 the evolutionary point of view. 



We can assume neither natural fitness or perfection in 

 nature by virtue of a purposeful creation, nor an automatic 

 adjustment of human affairs through natural selection. We 

 proceed to supplement our shortcomings by applying scien- 

 tific research to our specific problems. We shall replace a 

 shortage of sunshine with mercury-vapor lamps. We shall 

 avoid scurvy by doctoring our food. We shall avoid malaria 

 by exterminating mosquitoes. We shall eliminate smallpox 

 by extending vaccination. We shall correct hernias and 

 prolapses of the viscera by surgical intervention. In other 



