CUMULATIVE EVIDENCE FOR EVOLUTION 



By Horatio Hackett Newman 



Professor of Zoology in the University of Chicago 



No greater mistake about evolution could well be made 

 than to limit its application to living organisms. There has 

 undoubtedly been as real an evolution of the Cosmos, of the 

 solar systems, of the earth and other planets, of the molecules, 

 and of the atoms as there has been of organisms. All of 

 these have much in common. In none of them is there any 

 fixity or stability; in all of them there is rhythmic and orderly 

 change. In none of them does the course of change proceed 

 steadily in one direction. On the contrary, it commonly seems 

 to proceed from states of less complexity to states of greater 

 complexity and then to revert to states of less complexity. 

 For example, according to the latest theory, a sun such as our 

 own — and there are hundreds of millions of these in our own 

 galaxy alone — is believed to have had many vicissitudes dur- 

 ing its lifetime of quintillions of years. In the course of its 

 wanderings through space it may come relatively close to 

 another passing sun and during this passage givt birth to a 

 family of planets, each of which is its child. As one would 

 expect of a sun's child, each planet has a long period of 

 growth, a period that lasts for billions of years. Sooner or 

 later, however, our sun may come again within the gravita- 

 tional reach of another sun, the calculated average interval 

 between such approaches being, in round numbers, a billion 

 times a billion years. When this happens, the first family of 



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