Preface 



It is a remarkable circumstance that the quest of the ancient Ionian 

 philosophers for a cosmic unifying principle should have remained 

 somnolescent for over two thousand years and then be realized to a 

 startling degree in the last two hundred. The lonians recognized 

 that both animate and inanimate matter have so much in common 

 that they must be made "of the same stuff." The evolutionary theories 

 of Lamarck, Darwin, and Wallace demonstrated the historical con- 

 tinuity of life and guessed at the transition from inanimate to ani- 

 mate matter. In more recent decades chemical and physical con- 

 cepts have virtually bridged this transition and subatomic discover- 

 ies have linked matter as we see it on the earth with the earliest 

 stages of cosmic evolution. When evolutionary ideas are extended 

 into community and biome formation, there emerges a postulated 

 continuity of events from the earliest cosmic conditions to the most 

 highly organized communities in nature. This full sweep of evolu- 

 tionary theory is indeed tantamount to a unifying principle of the 

 universe. 



Perhaps no field of study combines so many facts and theories 

 from so broad a spectrum of science as does the study of evolution. 

 It is a synthesis of facts and theories from zoology, botany, bio- 



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