Considered one of the century's most important evolutionary biologists, Ernst Mayr has made major contributions to ornithology, evolutionary theory, and the history and philosophy of biology. He is best known for his work on speciation--how one species arises from another. In his more than sixty years in the United States, however, he has published hundreds of articles and more than a dozen books. Through these writings, he has not only clarified certain aspects of earlier scientific theories but proposed new theories which have changed the course of biological research.

Mayr was born on July 5, 1904, in Kempten, Germany, near the borders of Austria and Switzerland. He was one of three sons of Helene Pusinelli Mayr and Otto Mayr, who was a judge. As a boy, Mayr enjoyed bird watching. He received a broad education, including Latin and Greek. In 1923, he followed in the footsteps of several physicians in his...