2 The Expansion of Evolutionary Concepts 



writer Buffon and the English naturahst Erasmus Darwin were 

 prominent authors who set forth such ideas, Buffon timidly, Darwin 

 vigorously. Previously the scientific world had considered species 

 to be imchanging or immutable. 



It is undoubtedly no accident that the early suggestions of descent 

 by change were made during the period when Linnaeus and others 

 were developing a workable system for classifying living organisms. 

 These classifications must have focused attention on the close 

 similarity of many species and stirred speculation on the existence 

 of some sort of relationship among the members of the biota. Per- 

 haps contact with other progressive scientists of the time, such as 

 the chemists Priestley and Lavoisier, was a stimulus to more objec- 

 tive philosophical efforts in biology. Good communication appears 

 to have existed between the few scientists of that early period. 



In the first decade of the nineteenth century, the French natu- 

 ralist Lamark propounded a remarkably complete theory of the 

 evolution of organisms by a process of change. As a mechanism to 

 explain the change, he proposed that characters acquired during 

 the individual's lifetime are inherited. A battle royal, led by 

 Lamarck's compatriot Cuvier, began in opposition to Lamarck's 

 idea of the inheritance of acquired characters, and the ridicule 

 which smothered this idea threatened to engulf the whole idea of 

 evolutionary change. 



However, even while the idea of evolution was being bitterly 

 contested, a battery of brilliant scientists were making great changes 

 in the conservative intellectual attitude of Lamarck's time. In the 

 first half of the nineteenth century, Humphrey Davy and Faraday 

 established many of the modern concepts in electricity. In biology 

 Owen brought forward the idea of analogy and homology of parts; 

 Cuvier was solidifying the concepts of comparative anatomy already 

 firmly introduced by Lamarck; Milne Edwards propounded the 

 idea of division of physiological labor; Miiller demonstrated the in- 

 terrelationship of anatomy and physiology; Schwann and Schleiden 

 demonstrated the cell theory; Bichat founded histology; Von Baer 

 founded modern embryology; and Schultze defined protoplasm. 

 That these discoveries were made in such rapid succession is not 

 strange. Scientists had been on the verge of seeing them for years, 

 and, as one fundamental was discovered, it served as a key to unlock 

 the next half-anticipated secret. The whole spectrum of inquiry 

 oriented scientific thinking in terms of dynamic processes and inter- 

 relatedness. 



While these events were transpiring in the biological sciences, 



