Mendel's Legacy: The Origin of Classical Genetics (review)

Elof Axel Carlson offers this book as a first full historical assessment of the era of genetics from the rediscovery of Mendel around 1900 through Watson and Crick's model of DNA. Previous works followed what he calls the "review article" model, serving primarily to establish the basic chronology and intellectual sweep without delving deeply into individual papers in their own context. Carlson is well suited to his task, as a self-described "third-generation member of Morgan's Drosophila school through H. J. Muller with whom I received my Ph.D." (p. x) who has also given long service to the history of science through such works as The Cell: A Critical History (1966) and a biography of his mentor (1981).

Carlson explores the puzzle of why classical genetics flourished in the United States while it drew on four heretofore largely European research programs: breeding analysis, cytology, evolution, and developmental biology. His answer is that Johns Hopkins University created a new model of graduate education that stressed the Ph.D. as the culmination of scholarship that was both in-depth and liberal. The importance of biology in the new curriculum was underscored by Thomas Henry Huxley's speech at the 1876 inauguration of the university, and by the place of W. Newell Martin and William Keith Brooks on the founding faculty. Carlson also suggests that the lack of established medical schools in the United States made possible independent scholarship in biology; in Europe, medicine had been the vehicle for nearly all research in the life sciences. The "creation and dissemination of knowledge" that Daniel Coit Gilman, first president of Johns Hopkins University, stressed as the major role of his school, could develop in biology free of medical constraints. Meanwhile, the founding of Johns Hopkins Hospital in 1889 and its medical school in 1893 helped usher in the reform of U.S. medical education.

Carlson strives to give a balanced view of the contribution of other workers besides the Drosophila researchers, with chapters on plant breeding generally, maize genetics specifically, and animal genetics. He discusses the further botanical researches of the Mendel rediscoverers (Hugo de Vries, Carl Correns, and Erich Tschermak); such maize researchers as E. M. East, R. A. Emerson, and Barbara McClintock; and, at least briefly, W. E. Castle and others who worked with vertebrates are mentioned (the last is the shortest chapter in the book, just seven pages of text). However, it is only with T. H. Morgan and the fruit fly laboratory at Columbia that Carlson can say, with much justice, that "classical genetics was now launched" (p. 176).

This is a handsome book, with high-quality paper and many useful, well-captioned illustrations, including title pages of classical works in the field. The overall impression is of a textbook or encyclopedia, for the text is arrayed in two columns per page and broken into short sections of just a few paragraphs. The headings of these sections seem to be parts of a lecturer's course outline, while asides that might hold students' interest, such as the reasonable inference as to the source of the human sperm that Antoni van Leeuwenhoek studied, also give this project a classroom feel.

Carlson raises some interesting historiographic and methodological points, among them that this history is one of the cumulative "winning of the facts" as opposed to a Kuhnian paradigm shift. He also views his story as one of the triumph of reductionism, though, importantly, classical genetics still has a role to play even in an age of molecular genetics. These are rich, important ideas—but the short sections impart a choppiness to the argument that leaves these and other points raised but not fully developed.

That said, Carlson has made an important contribution in tracing Mendel's Legacy.