WHAT EVOLUTION IS 103 



as he wished and thus attained his 

 end. Darwin called this process arti- 

 ficial selection and believed it to be 

 the method by which man had pro- 

 duced from comparatively few wild 

 sources the great variety of domesti- 

 cated forms with which he was sur- 

 rounded. 



Darwin then raised the question, 

 Is there not a similar process going 

 on in nature as a means of producing 

 the limitless variety of life in the 

 open? This he believed to be so and, 

 in contrast with artificial selection, 

 he designated this process as natural 

 selection. The grounds for his belief 

 in natural selection as an actual proc- 

 ess in nature may be briefly stated in 

 the following way. 



More organisms are produced than 

 can possibly continue to exist because 

 of the limitations of food, space, and 

 other essentials. This comes about 



