4 EVOLUTION AND GENETICS 



From the first realization of evolution as a natural process by 

 which species are developed from preexisting species, and from 

 the first sound attempts to explain this process there arose a 

 series of theories which we can still believe in part. It was only 

 a natural outcome of scientific progress that a reaction to this 

 method should take place. Science needs working hypotheses, 

 but sooner or later these must be soundly rooted in fact and the 

 twentieth century has seen a vigorous attempt to discover the 

 underlying principles of all types of development. The most 

 significant field of investigation has been the relationship of 

 individuals of different generations, the process of heredity. The 

 science of genetics has explained many phenomena of heredity. 

 It is still impossible to correlate genetics wholly with other fields 

 of biology and to determine just how the transition from species 

 to species is brought about in evolution but we no longer lack 

 a foundation of soundly organized facts for interpretation. 



However willing we may be to refer ultimate causes to faith in 

 God or some mystic force, we cannot fail to admit that in man's 

 knowledge of the living things al)Out him there is much that is 

 within his power to explain on a basis of natural laws. That in- 

 quiry into these things need conflict with other fundamental 

 beliefs is a product of the imagination of those who do not, will not, 

 or cannot understand the findings of science; if faith without 

 understanding is beautiful, then faith with understanding is tran- 

 scendent. We can conclude no better than with the ideas expressed 

 by Erasmus Darwin in his Zoonomia: "The world has been evolved, 

 not created; it has arisen little by little from a small beginning 

 and has increased through the activity of the elemental forces 

 embodied in itself, and so has rather grown than suddenly come 

 into being at an almighty word. What a sublime idea of the in- 

 finite might of the great Architect! the Cause of all causes, the 

 Father of all fathers, the Ens entium! For if we could compare 

 the Infinite it would surely require a greater Infinite to cause the 

 causes of effects than to produce the effects themselves. 



"All that happens in the world depends on the forces that pre- 

 vail in it, and results according to law; but where these forces and 

 their substratum. Matter, come from, we know not, and here we 

 have room for faith." 



