The Adventures of Punctuated Equilibria. A Struggle for Authority in the Evolutionary Sciences. By Andrew James Grimshaw, B.Sc (Hons) Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy Deakin University, April 2001 Signed statements regarding this thesis. This thesis is an original work by myself. In cases where reference is made to the work of others due acknowledgment is given. ………………………………. (Andrew Grimshaw) Date: ………………………………. Any material in this thesis which has been accepted for a degree or diploma by any institution is identified in the text. ………………………………. (Andrew Grimshaw) Date: ………………………………. This thesis may be made available for consultation and loan. Copying of any part of this thesis is prohibited for two years from the date this statement was signed; after that time limited copying is permitted in accordance with the Copyright Act 1968. ………………………………. (Andrew Grimshaw) Date: ………………………………. ii For Frances Acknowledgments First and foremost I would like to thank the two people who have supported me through the four years it has taken to complete this thesis, Dr. Barry Butcher and Brenda Grimshaw. Barry has given both encouragement and balance, supplying enthusiasm when mine was lacking, reading my texts and playing devil’s advocate to my ideas. Brenda has been a constant source of strength, patiently listening to my thoughts when I needed a sounding board and to my grumbles when I felt like I’d had enough. Without either of these two this thesis would never have come to fruition. Others I would like to thank are: my parents, Pat and Roger, who have always been my inspiration; David Turnbull, for helping me get my theory straight; my correspondents, Robert Anstey, Alan Cheetham, John Endler, Douglas Erwin, Michael Ghiselin, Norman Newell, David Raup and Rick Winterbottom for helping me to understand the issues from a scientist’s perspective (Alan Cheetham, by far my most constant and thorough correspondent, deserves particular recognition in this respect); all the other scientists who filled in the questionnaires; all my other friends and family who have at different times and often without realising it supplied me with ideas and encouragement. iii Table of Contents Abstract 1 Chapter 1: Introduction 2 1.1: Overview. 2 1.2: The socio-philosophical perspectives of Pierre Bourdieu and Bruno Latour. 7 1.3: Rhetoric. 17 1.4: Jean Gayon’s analysis of punctuated equilibria. 23 1.5: A note on the nature of communication. 25 1.6: Other Historical Accounts of Punctuated Equilibria. 27 Chapter 2: Materials, prehistory and the 1970s. 31 2.1: Material aspects of the debate (fossils and flies). 31 2.2: Prehistory. 39 2.3: The 1970s. 44 Chapter 3: Constructing the revolution. 66 3.1: The relationship between rhetoric and scientific facts. 66 3.2: The book. 67 3.3: The article. 69 3.4: Citation analysis. 81 Chapter 4: Maintaining the revolution. 96 4.1: 1977 - a new dichotomy. 96 4.2: 1986 – making history. 110 4.3: 1993 – declaring victory 113 4.4: A summary and a question. 117 iv Chapter 5: Early 1980s – the peak of the controversy. 118 5.1: Overview. 118 5.2: Important issues of the time. 121 5.3: The punctuationists throw down the gauntlet. 127 5.4: The biologists’ reactions. 143 5.5: An exchange from Nature. 152 5.6: Summary 154 Chapter 6: The late 1980s and the 1990s. 157 6.1: The history. 157 6.2: The questionnaires. 167 6.3: Correspondence. 179 6.4: Textbooks. 184 6.5: Ego clashes. 189 6.6: Conclusion. 194 Bibliography. 197 Appendix: The questionnaire. 211 v Abstract The theory of ‘punctuated equilibria’ was formulated by two paleontologists, Niles Eldredge and Stephen Gould, in 1972 and has been the focus of considerable controversy within the evolutionary sciences ever since. The primary intentions of this thesis are to relate the history of punctuated equilibria and to examine how it has affected evolutionary science. Several modes of analysis have been used to illuminate the history: The sociological perspectives of Pierre Bourdieu and Bruno Latour (who see scientific debate as a ‘struggle for authority’); Rhetorical analysis of some of the key documents; Communication with practising scientists via questionnaires and correspondence; Citation Analysis. Chapter 1 gives a short summary of the history and introduces the methods and socio-philosophical perspectives used to illuminate the history. Chapters 3 and 4 examine the rhetorical process by which Eldredge and Gould constructed the ‘punctuationist revolution’. Chapters 2, 3, 5 and 6 relate the history of punctuated equilibria. 1 Chapter 1 Introduction. 1.1: Overview. Evolution is one of the great stories of the modern (Western) age. It tells us of our biological origins and of our relationship to the living world. Regardless of what one may feel about the certainty of scientific knowledge it must be conceded that evolution takes its place in the tradition of origin myths along with those of other times and cultures. This thesis will provide an account and analysis of a contemporary debate about the nature of evolution (approximately 1970 to the present). Some of the people involved in this debate are well known (Stephen Jay Gould, Richard Dawkins). There are others that are not so well known but probably more influential within the field of evolutionary science1 (John Maynard Smith) and there are others again who are probably neither famous nor particularly influential but who have interesting things to say. Amongst these scientists there exists competition to be the pre-eminent story- teller. Each scientist believes that their story is the one that explicates evolution the best. Scientist’s stories usually revolve around a core set of concepts. The focus of this thesis is the scientific argument over the veracity of one such concept – the theory of punctuated equilibria. For over 25 years now it has been the subject of substantial, and often heated, debate. Scientists, such as Alan Cheetham, Elizabeth Vrba and Steven Stanley, have taken it under their wing and used it as the basis for research programmes It has been heralded by some as the harbinger of a new evolutionary synthesis. Others such as Richard Dawkins and John Maynard Smith, have denied its significance, saying, basically, “we knew it all along, it’s part of standard neo-Darwinian theory and it’s not important anyway”. It is well known enough among university students to have been given a nickname - “punk eek”. ((Willis 1989), p.114) Punctuated equilibria2 was first conceived by Niles Eldredge. He presented his ideas in a 1971 article published in the journal Evolution (Eldredge 1971). However it is the 1972 article co-authored with Stephen Jay Gould, ‘Punctuated Equilibrium: An Alternative to Phyletic Gradualism’, published in the book Models in Paleobiology, that 1 The phrase ‘evolutionary science’ is used as a group term denoting all sciences that are concerned with evolution. ‘Evolutionary science’ thus includes evolutionary biology, paleontology, ecology, systematics and various other sub-fields. Often the term ‘evolutionary biology’ is used in such a context. However I have found that such usage creates confusion – many paleontologists, for instance, do not class themselves as ‘evolutionary biologists’. 2 Note that the term ‘punctuated equilibria’ refers to two objects - a set of empirical statements and a set theoretical statements. The theoretical statements are designed to explain the ‘facts’ as described by the empirical statements and/or to extend to other areas of evolutionary explanation. A simple analogue is Newtonian gravity. There is gravity as an empirical fact (things fall to the ground), then there is a set of theoretical statements designed to explain gravity (why things fall) and/or to extend to other areas of physical explanation (why the planets go round the sun). 2 has become the best known is generally cited when scientists refer to punctuated equilibria in the literature.(Eldredge and Gould 1972). At the core of punctuated equilibria is an empirical statement about the nature of data from the fossil record. This statement has two parts: first, that most species as recognised in the fossil record show little change for most of their existence (stasis); second that speciation is usually a geologically sudden event (punctuation). At this empirical level punctuated equilibria is not particularly controversial and would not be subject to challenge from outside paleontology. It is the theory of punctuated equilibria that has been the source of most of the controversy (the theory being the explanation offered for the apparent empirical facts). The authors of the theory, and others too, have used it as the basis of some rather ambitious assertions about the nature of evolution.3 Punctuated equilibria has been at the center of many (often controversial) challenges to neo-Darwinism. Starting with the 1972 article Eldredge and Gould have repeatedly claimed that punctuated equilibria has consequences for evolutionary biology4 as well as for paleontology. The specifics of these claims have changed over time but the basic structure remains the same – that punctuated equilibria implies that the explanatory domain of standard neo-Darwinism, as described by the Modern Synthesis, does not encompass macroevolution5 Many other scientists (mostly paleontologists) have joined them in challenging the validity of standard neo-Darwinism with respect to macroevolution, punctuated equilibria taking on a greater or lesser role depending on the nature of the specific assertion.6 Other scientists, mostly evolutionary biologists, have disputed these challenges. The first question that springs to mind here is ‘Why did these scientists feel it necessary to dispute the application of neo-Darwinism to macroevolution?’. There is, of course, no simple reply to this. The answer varies from scientist to scientist and each scientist, being human, has a diverse set of motivations. However there were some principal motivations shared by almost all the scientists in question.