The Search for Ancient DNA, the Meaning of Fossils, and Paleontology in the Modern Evolutionary Synthesis Elizabeth Dobson
Total Page：16
File Type：pdf, Size：1020Kb
Florida State University Libraries Electronic Theses, Treatises and Dissertations The Graduate School 2012 The Search for Ancient DNA, the Meaning of Fossils, and Paleontology in the Modern Evolutionary Synthesis Elizabeth Dobson Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected] THE FLORIDA STATE UNIVERSITY COLLEGE OF ARTS AND SCIENCES THE SEARCH FOR ANCIENT DNA, THE MEANING OF FOSSILS, AND PALEONTOLOGY IN THE MODERN EVOLUTIONARY SYNTHESIS By ELIZABETH DOBSON A Thesis submitted to the Program in History and Philosophy of Science in partial fulfillment of the requirements for the degree of Master of Arts Degree Awarded: Summer Semester, 2012 Elizabeth Dobson defended this thesis on March 26, 2012. The members of the supervisory committee were: Frederick Davis Professor Directing Thesis Michael Ruse Program Director Gregory Erickson Committee Member Scott Steppan Committee Member The Graduate School has verified and approved the above-named committee members, and certifies that the thesis has been approved in accordance with university requirements. ii To my fiancé, Patrick Jones iii ACKNOWLEDGMENTS First, I would like to thank my former professor, Mary Schweitzer, who first inspired my passion for paleontology. Without her love and support, the following work would not have been possible. I would also like to thank my former professor and advisor, William Kimler, who first taught me to think, research, and write as a historian of science. I am indebted to these two mentors, for without them I may have never learned to merge my passion for history with my love of paleontology. Next, I would like to thank my committee members who contributed to this work in many ways. I am especially grateful for my current professor and advisor, Frederick Davis. Your attentive guidance and constant encouragement helped to make this project a reality. Thank you for believing in me. Thank you also to Michael Ruse for your philosophy and support of my studies. I have grown so much under your guidance. Thank you for all you have taught me. Many thanks go to Gregory Erickson who has been a most valuable mentor over the past two years. Thank you for your direction and for further inspiring my research in paleontology. I would also like to thank Scott Steppan for clarification and careful comments on chapter three and the work as a whole. Special thanks also go out to a number of admirable scientists: Mark Norell, Jack Horner, Hans Larsson, Peter Dodson, and Brent Breithaupt. I appreciate your time, your insights, and your interest in the construction of this work. I am especially appreciative of Derek Turner who has proved an essential sounding board from afar. I want to also thank Ronald Doel, Kristine Harper, and Paul Brinkman for helpful suggestions. Many thanks go to my friend, Lindsey Newberry, for her thorough edits on every chapter. Most importantly, I am forever grateful for my family and their unfailing love and support. Thank you to my parents, Allen and Martha Dobson, and also my siblings, Robert and Sara. Finally, I want to offer a special thank you to my fiancé, Patrick Jones. Your love and patience over the last two years will always be remembered. I cannot begin to thank you enough. iv TABLE OF CONTENTS Abstract .......................................................................................................................................... vi INTRODUCTION ...........................................................................................................................1 CHAPTER ONE: LITERATURE REVIEW ...................................................................................5 CHAPTER TWO: PALEONTOLOGY FROM DARWIN TO DNA ...........................................21 CHAPTER THREE: THE SEARCH FOR ANCIENT DNA (1984-1991) ...................................47 CHAPTER FOUR: THE SEARCH FOR ANCIENT DNA (1991-1999) .....................................68 CHAPTER FIVE: MAKING SENSE OF ANCIENT DNA .........................................................91 CONCLUSION ........................................................................................................................115 REFERENCES ........................................................................................................................123 BIOGRAPHICAL SKETCH .......................................................................................................132 v ABSTRACT Reflecting on the history of paleontology, historian Martin Rudwick claimed, “The ‘meaning’ of fossils has been seen in many different ways in different periods.” This insight rings true today as the search for ancient DNA has provided a deeper meaning of the term fossil and offered paleontology a more expansive role in the molecular age. In this work, I provide a historical account of ancient DNA research from 1984 to1999 and discuss the implications of ancient DNA research as a new approach to fossil studies for the science of paleontology. The emergence of ancient DNA research over the past several decades has introduced a fresh and quantitative methodology for studying fossils and a new means through which to discover and decipher our evolutionary past. Ancient DNA research has revolutionized how scientists view and study ancient and fossil specimens. In doing so, the search for ancient DNA has transformed what was once a purely historical approach to fossil studies into a more experimental one. In this thesis, I argue that the early history of ancient DNA research, when appropriately situated in the overall history of paleontology, is best understood as an extension and realization of the modern evolutionary synthesis and a step toward bridging the gap between historical and experimental science. vi INTRODUCTION In February 2012, a team of Russian scientists announced the resurrection of an Ice Age plant from ancient tissue, frozen and preserved, in the nest of squirrel that lived some 30,000 years ago. In this report, Svetlana Yashina, of the Institute of Cell Biophysics at the Russian Academy of Sciences, and colleagues announced, “Late Pleistocene plant tissue of S. stenophylla, naturally preserved in permafrost, can be regenerated using tissue culture and micropropagation to form healthy sexually reproducing plants…At present, plants of S. stenophylla are the unique representative of ancient higher plants to be cultivated successfully.”1 The Russian scientists’ report captured the imagination of the world press. USA Today, The London Telegraph, and Discover all carried the story. The prospect of bringing ancient and even extinct creatures back to life is an idea that first became a conceivable reality with the advent of ancient DNA research in the mid-1980s. Shortly after, the idea of resurrecting the past gained popular appeal when Michael Crichton published his highly sensational science-fiction thriller, Jurassic Park. However, the scientists behind this specific study were more realistic about the implications of the ancient Ice Age plant and what this report means for science. Reflecting on the study’s findings, Yashina and fellow researchers claimed, “This natural cryopreservation of plant tissue over many thousands of years demonstrates a role for permafrost as a depository for an ancient gene pool, i.e., preexisting life, which hypothetically has long since vanished from the earth’s surface, a potential source of ancient germplasm, and a laboratory for the study of rates of microevolution.”2 This mildly fantastical account of the Ice Age plant resurrection, when compared to the imaginative world of Jurassic Park, is perhaps indicative of the past several decades of ancient DNA research and a more realistic vision of the potential of this type of inquiry. Nevertheless, the idea that we can successfully recreate the past remains a hot – though controversial – topic even thirty years after the first ancient DNA study which suggested that raising the dead and buried may in fact be an obtainable scientific reality. In this work, I cover new ground in the history of paleontology. My argument, although spread across five chapters, is three-fold. First and foremost, I provide a historical account of 1 Svetlana Yashina, Stanislav Gubinb, Stanislav Maksimovichb, Alexandra Yashina, Edith Gakhovaa, and David Gilichinsky “Regeneration of whole fertile plants from 30,000-y-old fruit tissue buried in Siberian permafrost,” Proceedings of the National Academy of Sciences (2012): 4. 2 Ibid., 1. 1 aDNA research from its inception in the 1980s until the turn of the twenty-first century. To develop this point, I must situate aDNA research into the broader history of paleontology. Chapter one provides a literature review of the history of the life sciences with an emphasis on paleontology. This historiography establishes a backdrop from which to understand the more general trends in the history of the life sciences from Darwinian evolution, classical genetics, and the modern evolutionary synthesis to molecular biology, molecular paleontology, and paleobiology. More importantly, I note how these trends were critical influences on the development of paleontology as a science and profession and how they affected paleontology’s role in evolutionary discussion from the mid-nineteenth to late twentieth century. In chapter two, I discuss more specifically paleontology’s significance in evolutionary theory from Darwin to DNA. This chapter explores paleontology as evidence of evolution and its role in Darwin’s argument