ERNST MAYR AND EVOLUTIONARY BIOLOGY.

Abstract

It is possible to feel such communion with the works of our scientific predecessors as to inspire not only admiration, but also gratitude and even affection. Long before I met him, Ernst Mayr profoundly affected my development, for probably the most influential event of my graduate education been a year-long, line-by-line exegesis, in a graduate course, of his monumental Animal Species and Evolution (196 3), published in the year I entered graduate school. From the publication of his first great synthesis in the year of my birth (Systematics and the Origin of Species, 1942), through Animal Species and Evolution, to his sweeping historical Gesamtkunstwerk (The Growth of Biological Thought, 1982a) and his innumerable essays, Ernst Mayr, in a career that so far has spanned 71 years of publication, has taught, provoked, and inspired generations of biologists, standing before them as a model of insatiable intellectual curiosity, ceaseless scholarship, and profound love of the diversity of nature. As he completes his ninetieth year, I am honored to join in offering a few reflections on Ernst's contributions to evolutionary biology. In autobiographical reflections (Mayr and Provine 1980, pp. 413-423; Mayr 1992b), Mayr recalls that, introduced to natural history by his father (a judge), he became an ardent naturalist and knew all the local birds by the age of ten. Neither in his gymnasium in Dresden nor in his undergraduate years as a medical student (in Greifswald, chosen because it was located in the ornithologically most interesting area in Germany) did he have much exposure to or interest in evolution. He entered the Ph.D. program in zoology at the University of Berlin in 1925, took required examinations in subjects that included philosophy (a lifelong interest thereafter), and studied under the eminent bird systematist Erwin Stresemann, who held quite a modern concept of species but otherwise few modern evolutionary ideas. The prevailing state of evolutionary theory is reflected in Mayr's own beliefs at this time, as illustrated by the Credo of a Lamarckian that he wrote in a college notebook in 1926 (1992a). Upon completing his Ph.D. after 16 months (on range expansion of a finch), he became an assistant in the University Museum. Apparently his interest in evolution, spurred by taxonomic problems in species and races of birds, grew at this time, his thinking being influenced by Stresemann and by the writings of his fellow assistant Bernhard Rensch (whose travels prevented much personal interaction). The greatest ambition of my youth, to study life in the tropics, was fulfilled in 19281930, when he spent 2/2 years collecting birds in the interior of New Guinea and the Solomon Islands, an experience that had an impact on my thinking that cannot be exaggerated (1976, p. 1). Mayr attributes his success as a collector to his earlier devotion to bird behavior (1976, p. 675). Shortly after returning to Berlin, he went (1931) to the American Museum of Natural History in New York, hired to revise the huge collection of birds taken by the Museum's Whitney South Sea Expedition. This collection and the Rothschild collection of 280,000 skins, acquired by the Museum shortly thereafter, occupied him for the next ten years, and provided the abundant material he would later use to illustrate principles of variation, speciation, and biogeography. His discussions of evolution with fellow curators were apparently less influential than his extensive and diverse reading, and his interactions with geneticists at Columbia University, including Dobzhansky after 1940. Mayr says that when he gave his Jesup Lectures in 1940, expanded into Systematics and the Origin of Species, his knowledge of genetics was very limited, but that it grew under the influence of his Columbia friends, and especially during summers at the Cold Spring Harbor Laboratory (1943-1952), where he collaborated with Dobzhansky on studies of mating behavior and sexual isolation in Drosophila (on which he wrote five papers). Appointed Alexander Agassiz Professor in Harvard's Museum of Comparative Zoology in 1953, and later its director, Mayr has devoted much of his subsequent career to the books, essays, and theories of speciation and evolution for which he is best known. Mayr is perhaps the living epitome of the Evolutionary Synthesis, and as synthesizer he is most familiar. But we should not forget his original,