ORGANIZING DRIVE OF EVOLUTION 7 



process. In the classical view of evolution it seemed appar- 

 ent that, on the whole, plants and animals fit the place in 

 which they live. They are fitted to their surroundings by 

 adaptations which, under the guiding action of Darwin's 

 natural selection, in some way confer biological advantage 

 upon them— "the survival of the fittest." In the more modem 

 view, as will be brought out, the geneticist sees a controlling 

 mechanism arising out of the origin of the hereditary deter- 

 miners, the genes, which become solely responsible for all 

 organisms, past and present, through an eon of structural 

 change or mutation, guided by adaptive selection. 



Trial and error characterize the situation— not intelligent 

 direction from within or without. Orthodox evolutionists 

 emphasize the mechanical aspects of the process and fail to 

 find any design or purpose. And, indeed, from most points 

 of view they are justified. The tremendous scale and terrible 

 ruthlessness of the destruction of endless kinds of organisms, 

 the blind and seemingly vicious struggle, the countless fail- 

 ures ending in "dead ends" and extinction, the rough going, 

 and the obviously unsentimental nature of reality have all 

 made a deep impression on the serious student of evolution. 

 Only some physical scientists, philosophers and theologians, 

 and wishful thinkers have been able in their almost complete 

 ignorance of biology to ignore these facts of nature. 



Any review of the varieties of organisms on this earth and 

 their history would necessarily bring out evidence that pur- 

 pose in the paleontological record is difficult to visualize on 

 purely scientific grounds. It would seem necessary to as- 

 sume extra-terrestrial forces, to set up dualistic explanations 

 such as a personalized God, or a Bergsonian "elan vital," or 

 the telefinalism of most theology. Biological scientists who 

 are deeply familiar with the organic history of this earth 

 have been unwilling to assume the very awkward position 

 of placing the burden of life's gallant struggle on the shoul- 

 ders of such omnipotent supernatural forces. They would 

 not feel comfortable, knowing that the divine guidance had 



