AN ABSTRACT OF THE THESIS OF H. Terry Taylor for the degree of Master of Arts in General Science (History of Science) presented onAugust 17, 1983 Title: William Ernest Castle: American Geneticist. A Case-Study in the Impact of the Mendelian Research Program Redacted for Privacy Abstract approved: In their modern context questions of heredity have come to be closely aligned with theories of evolution because all such theories require the presence of heritable variation. Thus the need for an understanding of a source of variation and a mechanism for its in- heritance became very apparent with the general acceptance of organic evolution among biologists in the 1870's. Yet no one theory of evolution or of heredity became generally accepted until the modern synthesis of the 1930's. This thesis ad- dresses the question of how this modern synthetic theory gained wide- spread acceptance and seeks to answer it by studying the development of a theory of heredity both before and after the rediscovery of Mendel ca. 1900. Those factors making possible the rediscovery in terms of the developments in heredity and evolution are treated as a background for the reception of Mendel. Theories discussed include those of Charles Darwin, August Weismann, Hugo de Vries and the American neo- Lamarckians. These theories also serve as a background against which to see the life and work of William Ernest Castle. This man was trained during the 1890's, receiving his Ph.D. under E.L. Mark at Harvard. In 1900 he became one of the very first to begin Mendelian experiments on animal material, working with small animals. Castle's life and work extended into the second half of the twen- tieth century and his career, therefore, reveals much of the development of genetics in the United States. Thus his work serves as a focus for an understanding of the impact of the Mendelian research program on the biological community. Castle was important as a popularizer of Mendel- iam, as a theoretician of sex-heredity, and as a mammalian geneticist. In addition, he did much to shape American genetics by his training of twenty Ph.D. geneticists at Harvard. The work of William Castle also included a lengthy series of selec- tion experiments which served to elucidate the function of selection in evolution. The controversies generated by these experiments were very influential in leading many Mendelians to become Darwinian evolu- tionists and thus stand as a milepost in the development of the modern synthetic theory of evolution. Castle's position in history has been very tenuous because he was perceived as "wrong" in a number of controversies. But his work elab- orated and clarified important principles of modern genetic and evo- lutionary theory. This thesis stands as a contribution to an under- standing of the development of these theories by its focus on the work of William Castle. William Ernest Castle: American Geneticist A Case-Study in the Impact of the Mendelian Research Program by H. Terry Taylor A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Master of Arts Completed August 17, 1983 Commencement June, 1984 APPROVED: Redacted for Privacy Professor of History of Science in charge of major Redacted for Privacy Head of Department of General Science Redacted for Privacy Dean of Grad e School 0 Date thesis is presented August 17, 1983 Typed by Jane Tuor for H. Terry Taylor ACKNOWLEDGMENTS A Project of this size is not something any one person does. There are many whose help has been invaluable. I would like to thank my friends and fellow graduate students who have, more times than I can count, provided a listening ear or "gotten crazy" with me as I've tried to continue living as well as write a thesis. Among many others, I'd especially like to thank Lynn, Bob, and Ken & Marilyn without whose friendship and support this thesis could not have happened. Librairies and librarians have played an important role in my work and I gratefully acknowledge this help. The staff of the Kerr Library at Oregon State University has been unfailingly gracious and helpful; I have especially appreciated the speedy inter-library loan system. I also was privileged to have access to the library system of the Univer- sity of California at Berkeley. It was a pleasure to work with the staffs of the Bancroft Library and the Biology Library on that campus. Beth Carroll, Assistant Manuscript Librarian of the American Philosophi- cal Society Library in Philadelphia, aided me greatly in retrieving Castle's papers, working over long-distance and with short deadlines. To all these persons my thanks. My work in Berkeley was done as the guest of the office of History of Science and Technology under the direction of John Heilbron. I gratefully acknowledge the help of him and his staff in providing office space and access to the library system of the University. The environ- ment in that office was most enjoyable, largeley because of Jacqueline Craig and Amy Kivel, both of whom were never too busy to help in a multitude of ways. It was a pleasure to "rub shoulders" with scholars from around the world, as well as the other graduate students working there. I profited greatly by my time spent there. I would like to thank Dr. David Willis and the General Science Department for unfailing support and encouragement during my entire program. My thanks to Dr. Peter Dawson who read much of the manuscript and was instrumental in precluding mistakes in the technical areas of genetics and evolution as my "minor professor."My special thanks to Dr. Brookes Spencer who stepped into my committee at the last moment, cheerfully and graciously providing challenging input.My thanks also to Dr. James Morris whose help was invaluable along the way; especially important was his help in the more technical aspects of writing itself. Finally, it is a privilege to acknowledge Dr. Paul Farber, my major advisor. His role has been of a very special nature, for it was he who provided much of the environment and stimulus for my intellectual growth over the last two years. His ability to nurture and stimulate, even to direct, with no hint of control is almost uncanny -- and most appreciated. The freedom to choose my topic and develop it in my own way has been complete; but so also has been his support and encourage- ment at every step. To him must go the credit for whatever merit this thesis may possess; its deficiencies are entirely my own. TABLE OF CONTENTS INTRODUCTION 1 CHAPTER ONE: THE SCIENTIFIC BACKGROUND FOR THE RECEPTION OF MENDEL CA. 1900: I. THEORIES OF EVOLUTION 15 CHAPTER TWO: THE SCIENTIFIC BACKGROUND FOR THE RECEPTION OF MENDEL CA. 1900: II. THEORIES OF HEREDITY 42 CHAPTER THREE: THE LIFE AND WORK OF WILLIAM CASTLE 82 CHAPTER FOUR: WILLIAM CASTLE: CONTROVERSIAL GENETICIST AND DARWINIAN EVOLU- TIONIST 153 CHAPTER FIVE: SOME CONCLUSIONS REGARDING A SCI- ENTIST AND HIS SCIENCE 208 SELECTED BIBLIOGRAPHY 222 WILLIAM ERNEST CASTLE: AMERICAN GENETICIST A CASE-STUDY IN THE IMPACT OF THE MENDELIAN RESEARCH PROGRAM INTRODUCTION Prior to the publication by Charles Darwin (1809-1882) of his Origin of Species in 1859, few naturalists in the United States or Great Britain would have given much credence to the notion that species could be transmuted. Yet so persuasive was his argument (and the evidence he accumulated and presented to support it) that within a few years of its appearance, the Origin had transformed the thinking of many. The idea that extant species are the de- scendants of earlier, often extinct ones had, by 1870, come to be widely accepted. Organic evolution rapidly became a most important working hypothesis in the biological sciences. Darwin's mechanism for evolution was natural selection and largely by its operation, he supposed new species were created. Darwin's thesis was simple: As many more individuals of each species are born than can possibly survive; and as, consequently, there is a frequently recurring struggle for existence, it follows that any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected.1 1 Charles Darwin, On the Origin of Species by Means of Natural Selection or the Preservation of Favoured Races in the Struggle for Life (London: John Murray, 1859), fascimile of the first edition with intro. by Ernst Mayr (Cambridge: Harvard University Press, 1964), p. 5. 2 But persuasive though he had been in convincing his fellows of evolu- tion, his proposed mechanism for its accomplishment was not so well received. In the years which followed the Origin, Darwin's theory was attacked and revised and condemned. From the voluminous discussion which ensued emerged an almost bewildering array of evolutionary theories. In them were suggested numerous other mechanisms, some auxiliary to and some alternative to natural selection. In his masterful survey of the then-current standing of Darwinism, Vernon L. Kellogg (1867-1937) required nearly 200 densely-packed pages to discuss these, bearing, as they did, names such as "heterogenesis, orthogenesis, metakinesis, geographic isolation, biologic isolation, 2 organic selection [and] . orthoplasy." Two theories attained the greatest ascendancy in the United States as the century drew to its end. One of these was the important revision of Darwin's hy- pothesis known as neo-Darwinism. The other, quite inimical to Darwinian evolution, was called by its adherents neo-Lamarckism. With so many theories, each with its own proponents, it seems remarkable that any kind of consensus ever was reached on evolution.