Life Sciences in the Twentieth Century
by Garland E. Allen
Because of the central position that genetics has come to occupy in twentieth-century biology, its history has been more fully documented than that of fields such as embryology. A recent and general source for views on the history of heredity is Emst Mayr’s massive The Growth of Biological Thought (Cambridge, Mass.: Harvard Univ. Press, 1982), especially Part II (Chs. 14-19). A useful introduction to the secondary literature is Mayr’s essay review: “The Recent Historiography of Genetics,” Journal of the History of Biology, 1973, 6:125-154. The most general and in some ways most complete source of ideas on heredity from the Greeks through the nineteenth century is F. J, Cole’s Early Theories of Sexual Generation (Oxford: Clarendon Press, 1930). It does not treat the period after the rediscovery of Mendel in 1900, and it represents an older form of scholarship that is more descriptive than analyt ical. Yet it contains a wealth of information arranged chronologically. A more recent (and still available) general history is Hans Stubbe’s History of Genetics (Cambridge, Mass.: MIT Press, 1972). Less comprehensive but more pertinent to those with an interest in the twentieth century are L. C. Dunn, A Short History of Genetics (New York: McGraw-Hill, 1965), and A. H. Sturtevant, A History of Genetics (New York: Harper & Row, 1965). Both focus on the period since the rediscovery of Mendel and are what would today be called highly “internalist” histories (that is, focusing on the history of the scientific ideas apart from their broader social and historical context). In the same vein, but more detailed about the actual genetics, is Elof A. Carlson’s The Gene: A Critical History (Philadelphia: Saunders, 1966). All three books have useful bibliographies of primary (mostly published) materials, with Carlson’s being the most extensive.
A good deal of scholarly work exists on the life and work of Gregor Mendel (1822-1884), most of it pertinent to the history of twentieth-century genetics. Despite its age, Hugo Iltis’s Life of Mendel(New York: Norton, 1932) is still a standard source. A more recent, broader work is by the historian of science Robert C. Olby. In The Origins of Mendelism (New York: Schocken Books, 1966), Olby summarizes much of the nineteenth-century work leading up to Mendel and analyzes Mendel’s own work in this context. Vitezslav Orel’s brief biography, Mendel translated by Stephen Finn (New York: Oxford Univ. Press, 1984) focuses on Mendel’s work, but it is especially useful in describing the scientific, cultural, and agricultural milieu in Moravia at the time Mendel lived.
Mendel’s actual work, including the “problem” of his rediscovery,isthesubject of numerous writings. One of the most accessible is Curt Stern and Eva Sherwood’s The Origin of Genetics: A Mendel Source Book (San Francisco: Freeman, 1966). This book is particularly useful for students, since it contains reprints of a number of important papers by Hugo de Vries and RA. Fisher.
The historical problem of Mendel’s long neglect (thirty-five years from the publication of his paper on hybridization in 1866 until its rediscovery by Carl Correns, Erich Tschermak, and de Vries) has been the subject of many scholarly inquiries. Most of the arguments are summarized in Olby’s Origins and Mayr’s Growth. Robert Olby also published a challenging essay: “Mendel No Mendelian? ” History of Science, 1979, 17:53–72. Olby’s point is that much of what we call “Mendelian” today was not a part of Mendel’s original conception and can be claimed to be so only if we read the ideas back into his work. Augustine Brannigan in “The Reification of Mendel,” Social Studies of Science, 1979, 9:423-454, argues that Mendel’s main interest in hybridization lay in the light it could throw on the species problem, an issue that was less important to his contemporaries than the practical questions of animal and plant breeding. By 1900, Brannigan suggests, the species question had become of greater interest to the biological community, and hence there was a more favorable atmosphere for understanding and accepting Mendel’s main argument.
Prior to the rediscovery of Mendel’s work, Francis Galton (1822-1911)had already initiated a totally different approach to the problem of heredity: what became known as biometrics, or the measurement of traits within populations. The biometrical movement developed an extensive research program with Galton and, later, his protege Karl Pearson (1857-1936) as its leaders. A good introduction to the issues is William Provine’s Origins of Theoretical Population Genetics (Chicago: Univ. Chicago Press, 1971; esp. Chs. 2 and 3).
Historians with a more explicitly sociological point of view have since traced the origin and content of early biometrical work to the social class interests and perspectives of its founders. Of particular interest is Donald MacKenzie’s Statistics in Britain, 1865-1930 (Edinburgh: Edinburgh Univ. Press, 1981). MacKenzie emphasizes how the development of biometrical thought was intimately connected to social purposes such as eugenics in the work of Galton, Pearson, and R. A. Fuher.
The course of the debate between biometricians and Mendelians makes an important case study of the role of methodology in science. The controversy is the subject of the chapters in Provine’s Origins and of two interesting papers: Lyndsay Farrell, “Controversy and Conflict in Science: The English Biometric School and Mendel’s Laws,” Social Studies of Science, 1975, 5:269-301; and Donald MacKenzie and Barry Barnes, “Scientific Judgment: The Biometry-Mendelian Controversy,” in Natural Order: Historical Studies of Scientific Culture, edited by Barry Barnes and Steven Shapin (Beverly Hills, Calif.: Sage, 1979), pp. 191-210.
An important aspect of the history of Mendelian theory in the twentieth century has been the field of cytology–the study of cell structure and function. Most important for heredity, of course, is study of the cell nucleus, in particular the chromesomes. There was considerable debate in the late nineteenth and early twentieth centuries on the function of the chromesomes and the significance of the events surrounding mitosis and meiosis. A detailed and extensive analysis is Hermann J. Muller’s introduction to the reprint edition of E. B. Wilson’s The Cell in Development and Inheritance (New York: Johnson Reprint, 1966). Another comprehensive study is William Coleman’s “Cell, Nucleus and Inheritance: An Historical Study,” Proceedings of the American Philosophical Society, 1965, 109:124-158, which moves chronologically from Darwin’s pangenesis (his provisional speculations about hereditary units) to the more empirical work of August Weismann (1834-1937), to the discovery of nuclein, or DNA. This is a marvelous survey presented with a keen historian’s eye.
The so-called classical school of genetics arose after 1910 and is best characterized as the synthesis of Mendelian breeding experiments with cytological studies of chromosome structure and behavior. This work developed chiefly in the United States, though major contributions came from England, Germany, and Scandinavia. Several books deal wholly or in part with this period and can be used as a basic entry into the wider literature of twentieth-century genetics. Dunn (A Short History) and Sturtevant (A History) were both prominent practitioners of classical genetics, and it is not surprising that their histories concentrate heavily on the classical period. Carlson also focuses on that period in The Gene. Several biographies provide a good introduction to the basic developments. Thomas Hunt Morgan (1866-1945) is considered to be one of the major architects of the chromosome theory of heredity. His life and work is the subject of two biographies.
With mutation, one of the most influential concepts put forward in twentieth-century genetics was the distinction between genotype and phenotype, first enunciated by the Danish botanist Wilhelm Johannsen (1857-1927) in 1909. His work has been admirably discussed by Frederick Churchill in “Wilhelm Johannsen and the Genotype Concept,” Journal of the History of Biology, 1974, 7:5-30.
In addition to some skepticism about the importance of chromosomes, another stumbling block to the acceptance of Mendelian theory emerged in the 1920s and the 1930s: the concept of cytoplasmic inheritance. Cytoplasmic inheritance refers to the possibility that some traits are transmitted from parent (usually mother) to offspring through the egg cytoplasm rather than through the nucleus. Cytoplasmic inheritance and the opposition it met from classical geneticists are beautifully laid out in Jan Sapp’s “The Struggle for Authority in the Field of Heredity, 1900-1932: New Perspectives on the Rise of Genetics,” Journal of the History of Biology, 1983, 16:311-342. This article is a particularly fine integration of technical, sociological, and intellectual history. Complementing Sapp’s study is a recent paper by Jonathan Harwood, “The Reception of Morgan’s Chromosome Theory in Germany: Inter-war Debate over Cytoplasmic Inheritance,” Medizinhistorisches Journal, 1984, 19:3-32, which describes the mixed reception Morgan’s chromosome work received in Germany owing to the prevailing views there (and elsewhere in Europe) on the role the cytoplasm might play in heredity. Sapp’s more recent book, Beyond the Gene (Oxford Univ. Press, 1987), spells the story in more depth than his earlier article.
The history of human genetics has been the focus of only a few writings, despite its obvious-importance and interest. Three of these deserve special mention: Charles E. Rosenberg, “Charles B. Davenport and the Beginnings of Human Genetics,” Bulletin of the History of Medicine, 1961, 35 (3): 266-276; Curt Stern, “Mendel and Human Genetics,” Proceedings of the American Philosophical Society, 1965, 109 (4): 216-226; and, for post-1930s developments, the later chapters of Daniel J. Kevles, In the Name of Eugenics: Genetics and the Uses of Human Heredity (New York: Knopf, 1985).
The relationship between genetics and embryology in the twentieth century presents a curious mixture of integration and fragmentation. The overall history has been told by Viktor Hamburger in Mayr and Provine’s The Evolutionary Synthesis, pp. 97-111. More recent is Scott Gilbert’s insightful essay “The Embryological Origins of the Gene Theory,” Journal of the History of Biology, 1978, 11:307-351, which traces the development of the gene theory to embryological concerns with the problems of differentiation and control. The philosophical roots of the split between genetics and embryology after about 1915 are explored in Garland E. Allen, “T. H. Morgan and the Split Between Embryology and Genetics, 1910-1935,” in History of Embryology, ed. Herder et al, pp.113-144 (see Section 2 above).
Historical explication of the socioeconomic (agricultural) context of the origin of genetics has had a slow but increasingly promising start. One important proponent of this interpretation, Vitezslav Orel, Director of the Mendelianum of the Moravian Museum in Brno, has traced such interest in the work of Mendel himself. Orel’s short paper “Interest in Hybridization in Moravia before Mendel Came to Brno,” Journal of Heredity, 1973, 64(1), suggests a far closer relationship between Mendel’s interest in genetic transmission (as we call it today) and the problems of agricultural productivity than has been recognized before. See also V. Orel and R.J. Wood, “The Sheep Breeders’ Legacy to Gregor Mendel,” in Gregor Mendel and the Foundation of Genetics, edited by Orel and Anna Matalova (Brno: Mendelianum/Czechoslovak Society for the History of Science, 1983), pp. 57-75.
Several essays by Charles Rosenberg have suggested the importance in America of agriculture to the growth of genetics in the twentieth century. One of the few historians to follow Rosenberg’s lead has been Barbara Kimmelman, whose article “The American Breeders’ Association: Genetics and Eugenics in an Agricultural Context, 1903-1913,” Social Studies of Science, 1983, 13:163-204, shows clearly the importance many agriculturalists saw in Mendel’s work. A far more radical, overtly economic analysis can be found in R. C. Lewontin and Jean-Pierre Bertan, “Technology, Research, and the Penetration of Capltal: The Case of U.S. Agriculture,” Monthly Review, 1986, 38:21-34; and Bertan and Lewontin, “The Political Economy of Hybrid Corn,” Monthly Review, 1986, 38:35-47. Both articles are clearly presented and provocative.