Lerner, I. Michael (Isadore Michael), 1910-

Isadore Michael Lerner was a geneticist.

Isadore Michael Lerner was a geneticist.

Lerner's parentage made Russian his native language, but his command of English was superb. He spoke with little or no accent, his knowledge of idioms was excellent, and his written style, like that of another compatriot, Theodosius Dobzhansky, was marked by clarity and good syntax. He came to North America in 1927, a penniless refugee seeking a university education. By good luck, for it was the time of the Great Depression, he found a job digging ditches and watering chickens in the poultry farm of the University of British Columbia. Learning that in order to hold that job indefinitely he would have to pursue a major in poultry husbandry at the university, he entered upon a career in science almost fortuitously. After obtaining his bachelor's degree, he embarked upon graduate study, after being much encouraged by an interview with Theodosius Dobzhansky, who was visiting the university and whose enthusiasm and friendly advice made a great impression upon the young graduate student.

After obtaining his master's degree at the University of British Columbia in 1932, Lerner was told that financial stringency was forcing the university to eliminate his position. Fortunately for science, he obtained support for further graduate study at the University of California, Berkeley, in poultry husbandry. Upon receiving his Ph.D. degree, in 1936, Lerner was at once given a faculty position. He then moved up the academic ladder to the rank of professor, continuing for 22 years. In 1958, after the acclaim that met the publication of his first three books, he shifted to the Department of Genetics as its chairman. In 1963 he resigned that office, and ten years later became professor emeritus. During his last thirty years Lerner was plagued with much ill health. He underwent several abdominal operations and developed cataracts on both eyes, which were also operated on. Eventually he had a detached retina that greatly impaired his eyesight. In all these difficulties he was greatly assisted by his wife, Ruth Stuart, who had been a fellow student at the University of British Columbia and was a trained scientist herself. She was Lerner's eyes and ears in those last decades, and helped to produce the new editions of his books.

Lerner's career fell into three somewhat overlapping periods. During the first, he made fundamental contributions to poultry genetics and improvement. A majority of his published papers stem from that time. He first worked on the genetics of relative growth and disease resistance; then on components of egg production; the effects of selection in conjunction with inbreeding; empirical tests of theoretical predictions of gains from the simultaneous selection of several different characteristics; and the derivation of an "optimum selection index" that received wide attention and use and led to a doubling of egg production in commercial flocks.

The second period may be dated from the beginnings of his preparation for his acknowledged masterpiece, Genetic Homeostasis, a very important contribution to genetic theory. It embodies the idea that the most adapted type within a population is not one simply conforming to a phenotypic norm, but one whose development and reproductive life history adjust to the varying environment in such manner as to preserve high fitness. Correspondingly, the most successful population is one that can successfully meet the challenge of long-range environmental changes. Homeostatic devices that stabilize an individual's reproductive performance have high selective value; the population benefits from having a heterogeneous genetic composition even beneath an apparently uniform phenotype. Thus Lerner emphasized the very great importance in evolution of "buffered and balanced genotypes, integrated genepools, and coadaptation."

In Lerner's final period he attempted to introduce these evolutionary concepts into his teaching and social thinking. His superb textbook, Heredity, Evolution and Society, written after Curt Stern had joined the Berkeley faculty and become his friend, exemplified Lerner's cautious, critical attitude toward the extension of scientific evolutionary theory into human affairs. He was neither an extreme sociobiologist nor a virulent opponent of such ideas. He treated the most controversial subjects, such as the inheritance of intelligence, natural selection in human populations, and the nature of human races, with restraint, willingness to face facts and to admit ignorance. His breadth of knowledge in fields outside his specialties was extraordinary. In a single paper, for example, he quoted aptly from Isaiah Berlin, William Blake, Michelangelo, Samuel Butler, Bertrand Russell, Francis Bacon, Aristotle, and Bergson.