Ernst Mayr not only ranks among the great evolutionary biologists of this century; he is also one of the best writers. This collection is of lasting importance. -- E. O. Wilson

The diversity of living forms and the unity of evolutionary processes are themes that have permeated the research and writing of Ernst Mayr, a Grand Master of evolutionary biology. The essays collected here are among his most valuable and durable: contributions that form the basis for much of the contemporary understanding of evolutionary biology.

"Mayr has shown himself to be a true follower of Darwin, Wallace, and Huxley. His writings are lively and critical, and they provide remarkable insight into the development of the field." - Science

"The range of topics covered in these essays is awesome when one realizes that they are the product of a single mind." - Sciences