FOREWORD 



A symposium entitled Lectures in Biological Sciences was 

 held on the Knoxville campus of The University of Tennessee, 

 December 3-5, 1959, a week after the centennial date of the 

 publication of Charles Darwin's Origin of Species. The five 

 lectures were presented by scientists who have made important 

 contributions to the study of evolution. The theme of the 

 symposium was the nature and course of the evolutionary proc- 

 esses and their implications for man's physical and spiritual 

 well-being. 



It is perhaps particularly appropriate that what was prob- 

 ably the last of the celebrations of the Darwin Centennial was 

 held in East Tennessee, near the town of Dayton where the last 

 spectacular display of resistance to the acceptance of Darwin's 

 theory of evolution once took place. The centennial celebra- 

 tions, including that in Knoxville, were principally responsible 

 for the vigorous efforts of many prominent Tennessee scientists 

 and lay citizens to educate a large public to the knowledge that 

 there is practically universal acceptance among scientists of the 

 occurrence of evolution as an historical fact. 



It is perhaps trite, but necessary, to note that our knowledge 

 is incomplete; thus, details of the course of evolution and the 

 mechanisms by which it operates are in the realm of theory. 

 The lectures printed in this volume show us how ingenious 

 are the experiments, observations, and insights that have been 

 brought to bear on these theoretical problems and how much 

 knowledge has been revealed as the result. They also remind 

 us of how necessary it is to understand these problems if we 

 are to understand ourselves and to achieve success in improving 

 our destiny. 



The philosophical implications of our knowledge of evolu- 

 tion were discussed to a greater or lesser extent by all of the 

 speakers; for, as Professor Waddington said, and as Tennessee's 

 experience has shown, "The theory of evolution is . . . inescapa- 

 bly connected with the other systems of thought by which man 



