http://SaturnianCosmology.Org/ mirrored file For complete access to all the files of this collection see http://SaturnianCosmology.org/search.php ========================================================== *Controversy. Catastrophism and Evolution: The Ongoing Debate* A new book (c) 1998 by Trevor Palmer, Nottingham Trent University, UK *CONTENTS* *Chapter 1 - The Context of Evolution: the Earth and its Surroundings* 1.1 The chaotic Solar System 1.2 Possible causes of catastrophe on Earth 1.3 The fall and rise of catastrophism *Chapter 2 - The Establishment of Gradualism * 2.1 Catastrophism, gradualism and evolution 2.2 Myth, cosmogony and pre-nineteenth century catastrophism 2.3 Evolution or extinction?: conflicts between French catastrophists and gradualists in the years following the Revolution 2.4 Across the Channel: Hutton and his legacy 2.5 Natural theology and diluvialism in early nineteenth century Britain 2.6 The catastrophism-uniformitarianism debate in the 1830s and beyond 2.7 Lamarck, Darwin and evolution 2.8 From Darwinism to neo-Darwinism: short, slow steps to a gradualistic evolutionary synthesis *Chapter 3 - Gradualism under Challenge * 3.1 The birth of neocatastrophism 3.2 Eustasy, impacts and mass extinctions 3.3 Phyletic gradualism and quantum evolution 3.4 Punctuated equilibrium and species selection 3.5 Gould's view of life *Chapter 4 - Nemesis for Evolutionary Gradualism?* 4.1 Iridium, tektites and the death of the dinosaurs 4.2 From Snowbird I to Snowbird II: conflicting ideas about the K-T transition 4.3 A periodicity in extinctions? 4.4 Continuing arguments: rock hounds, stargazers and the high-tech people 4.5 Current views on mass extinctions *Chapter 5 - The Erratic Descent of Man * 5.1 Early scenarios of human evolution: slow, continuous progress towards more advanced forms 5.2 Gradualism sustained: developments in paleoanthropology from 1959 to 1979 5.3 The molecular revolution 5.4 From dinosaurs to hominoids 5.5 Hominids 5.6 Arguments over patterns in hominid evolution 5.7 The changing environment 5.8 Our uncertain origins *Chapter 6 - Towards a New Evolutionary Synthesis* 6.1 Darwinism challenged and defended 6.2 Life itself - accident or design? 6.3 More heat than light: the evolution debate as reflected in books of the early 1980s 6.4 Darwinism: what's in a name? 6.5 The continuing evolution of evolution 6.6 Evolution today: Darwinism, Lamarckism, Matthewism, or what? 6.7 The evolutionary significance of mass extinctions 6.8 The pattern of the past, and of the future *Postscript - The Hammer and the Pendulum* *References* *Index* *Controversy. Catastrophism and Evolution: The Ongoing Debate* *By Trevor Palmer* *Nottingham Trent University, UK* "/Prevailing views of patterns and processes in the evolution of life on Earth have changed in a significant fashion over the past few years...impacts of asteroids and comets have to be regarded as perfectly plausible agents of evolutionary change...a revolution in academic thought has taken place./" Recent geological discoveries profoundly challenge the once accepted theory that species follow a progression of gradual modifications determined by natural selection. Dramatic evidence in the fossil record of abrupt evolutionary change unearths new arguments on the origin and evolution of humanity, the history of the solar system - even the threat of extraterrestrial impacts to the earth. /Controversy/ puts the reader at the forefront of the scientific revolution against traditional views of evolution. The champion of alternative views, Catastrophism, declares that sudden cataclysmic events, such as meteor showers, cause mass extinctions followed by rapid bursts of new species - in direct opposition to the Modern Synthesis of neo-Darwinism, the offspring of Darwinism and Genetics, which maintains that evolution is slow, imperceptible, and progressive. Professor Palmer clearly traces the interactive histories of catastrophism and Evolution from ancient times to the present, contextualizing the struggle for dominance between these fundamentally different points of view. This versatile volume ranges freely over interdisciplinary territory that includes astronomy, biology, history, ands paleontology, to show how catastrophic events must be considered as agents of evolutionary change. If dated notions of gradualistic evolution are dying out, then it is Palmer who performs the autopsy in /Controversy/ - the latest specimen in a new breed of book. *Publishing details* *Plenum Publishing Corporation 233 Spring Street, New York, NY 10013-1578, USA* *Controversy. Catastrophism and Evolution: The Ongoing Debate* Published 1998. ISBN 0-306-45751-2 430 pages + index. Black and white illustrations. $85.00 ($102 outside US & Canada) *PREFACE* /Controversy/ tells how prevailing views of patterns and processes in the evolution of life on Earth have changed in a significant fashion over the past few years. In 1959, the centenary of the publication of Charles Darwin's /On the Origin of Species by means of Natural Selection/, the Modern Synthesis of neo-Darwinism, which incorporated developments in genetics into traditional Darwinism, seemed completely secure. Together with the contemporary geological paradigm, the Modern Synthesis was widely seen as representing the triumph of a gradualistic-uniformitarian view of Earth history over the catastrophist alternative. Evolutionary change was slow (an essential feature of gradualism), imperceptible (except over long periods of time) and progressive (though not because of linear development, but as a result of competition between variant forms). Later, however, it became increasingly clear that the course of evolution had been much less even-paced and much more erratic than previously realised, the fossil record revealing episodic rapid bursts and abrupt transitions, which could no longer, as formerly, be dismissed as artifacts. Moreover, from 1980 onwards, neocatastrophism made remarkable advances so that, today, impacts of asteroids and comets have to be regarded as perfectly plausible agents of evolutionary change, and evidence for such an extraterrestrial involvement at any particular time considered on its merits. Something of a revolution in academic thought has taken place, but as with other paradigm shifts in the scientific world, there are those who deny that it has happened. Inevitably, there are those who cling to the old ideas. As the great German physicist, Max Planck (1858-1947), wrote: "An important scientific innovation rarely makes its way by gradually winning over and converting its opponents; it rarely happens that Saul becomes Paul. What does happen is that its opponents gradually die out, and that the growing generation is familiarized with the ideas from the beginning". We humans being what we are, even when a Saul does become a Paul, he often denies that he has changed his name. So, as Archie Roy, Professor of Astronomy at Glasgow University, said at a Society for Interdisciplinary Studies meeting in London in 1985, it is not unknown for the response to a new idea to progress from, "This man is nuts", through, "We'll really have to look at the problem just to dismiss it", to, "Of course I've always known that this was the case". With the subject of evolutionary biology, which is our particular concern, the imprecise and subjective nature of some of the terminology makes it possible for those who wish to do so to maintain that the essentials of the gradualistic viewpoint remain intact. For example, a significant evolutionary change taking place over several thousand years (rather than several hundred thousand years) might be cited by some as an example of a rapid transition, while others would have no difficulty in accepting it as falling within the range that could be regarded as gradualistic. Hence, one of the aims of the present work is to go beyond assertions and give the full flavor of views about contemporary and historical evolutionary theory which have received wide circulation in books and general science journals such as /Nature, Science, Scientific American/ and /New Scientist/. The change in tone of such writings over the years is very apparent, leaving little scope for misrepresentation. Nevertheless, in order to convey opinions and arguments with maximum accuracy, exact quotations are given where considered appropriate. In the light of these, it should be evident that a major change of perspective, if not a revolution, has occurred over the past decade or so. *Chapter 1* of /Controversy/ serves as an introduction. It shows that catastrophic events in the form of collisions between cosmic bodies have occurred throughout the history of the Solar System; the Earth has suffered many impacts, most of them small, but some large enough to have caused widespread devastation, and today it is still threatened by orbit-crossing asteroids and comets. As we shall see, ignorance of this extraterrestrial dimension by nineteenth century catastrophists and uniformitarians alike contributed to the demise of catastrophism, and increasing knowledge of it in more recent years has stimulated the rise of neocatastrophism. Regardless of that, it is beyond question that mainstream scientists throughout most of the twentieth century considered catastrophism to be dead. *Chapter 2* looks at the nature of catastrophism in previous times, and the reasons for its apparent defeat by uniformitarianism in the nineteenth century. Uniformitarianism was formulated by Charles Lyell in a geological context, but many of its principles and attitudes were adopted by Charles Darwin for his theory of evolution, subsequently developed into the Modern Synthesis. There was a general belief that catastrophism and evolution were alternative, mutually exclusive, explanations for the fossil record and, as fossil evidence accumulated during the second half of the nineteenth century, it became increasingly clear that the features observed could not be explained by the Earth-centred model of catastrophism then in vogue, which linked extinctions of species to crustal upheavals on a global scale. Also, Lyell had deliberately caused confusion by giving two different meanings to uniformitarianism. Actualistic uniformitarianism, the principle that physical processes operate according to unchanging laws, was widely acclaimed by scientists of all persuasions, then and subsequently. In contrast, substantive uniformitarianism, the belief that human beings had been around long enough by Lyell's time to know that the Earth's present state was typical of its entire history, has received far less acclaim. Indeed, there seems to be no justification for excluding the possibility that major events caused by processes operating in accordance with unchanging natural laws should not occur in an episodic fashion, widely separated in time. Nevertheless, an unnecessary association was established between actualistic and substantive uniformitarianism and, since no global catastrophes had apparently been observed in historical times, uniformitarianism came to imply gradualism, this being stretched to include minor catastrophist elements such as earthquakes and volcanic eruptions. Then, as a result of distortions propagated by Lyell and others, subsequent generations were led to believe that the views of the catastrophists owed more to pre-conceived ideas than to observation, whereas the theories of the uniformitarians were all derived by logical deduction from observed data. At best this was over-simplistic, at worst a reversal of the truth, yet the myth became widely accepted. It also became received opinion, quite falsely, that the catastrophists relied on supernatural explanations for the cause of the major catastrophic events which had supposedly taken place. It is true that they refused to rule out the possibility of fresh creations of life at intervals throughout Earth history, but Lyell took exactly the same line himself, even after his formulation of uniformitarianism. Although he eventually accepted some aspects of Darwin's evolutionary theories in his old age, he always denied that humankind could have evolved from ape-like creatures, maintaining a firm belief that Man had a special status in Creation. So it can be seen that uniformitarians and catastrophists alike were products of their times, overlapping to a considerable extent in their religious beliefs and approaches to science. To put it bluntly, there is absolutely no intellectual justification for making critical judgements on catastrophists such as Sedgwick, Cuvier and Burnet, by the strict application of twentieth century standards, while making allowances for some of the "odd" views of the uniformitarians, Lyell and Hutton, not to mention other scientists such as Newton, because of the times in which they were living. Therefore, with the demolition of the myth that the nineteenth century catastrophists were driven by religious dogma rather than science, there remains no reason for having to distinguish between catastrophism and neocatastrophism in the twentieth century. *Chapter 3* is concerned with challenges to evolutionary gradualism up to the year 1980. Many of these challenges involved attempts to introduce extraterrestrial models of catastrophism. However, from the time of Aristotle onwards, there had always been considerable resistance to suggestions that the Earth might be subject to interference by external factors. Nevertheless, the extraterrestrial origin of meteorites was well-established by the start of the twentieth century, but not until the 1960s did it become generally accepted that impacts had caused many of the large craters found on the Earth's surface, and the arguments of M.W.de Laubenfels, René Gallant, Harold Urey, Digby McLaren and others that such impacts could have influenced the evolution of life fell on deaf ears, even though episodes of mass extinction were evident from the fossil record. Similarly, Otto Schindewolf's hypothesis that a supernova explosion could have been the cause of mass extinction events was largely ignored, while his view (and that of Richard Goldschmidt) that macromutations might account for the origin of new species provoked derision. Abuse was also poured on Immanuel Velikovsky for his theory that the Earth had suffered several major catastrophes as a result of coming into close contact with planetary-sized cosmic bodies. Norman Newell did much to establish that mass extinctions were real events, but he favored gradualistic explanations for their cause. This line was generally followed by evolutionary biologists, developing theories involving plate tectonics and continental drift. However, during the 1970s, the strictly gradualistic view of evolution came under challenge from within the Modern Synthesis by Stephen Jay Gould, Niles Eldredge and Steven Stanley, who argued that, according to the fossil record, evolutionary change tended to occur in rapid bursts separated by periods of stasis. Moreover, overall evolutionary trends were not necessarily determined by the gradual accumulation of small modifications. *Chapter 4* deals with the dramatic changes in attitude towards catastrophism since 1980, stimulated by the hypothesis of Luis Alvarez and colleagues that high iridium concentrations found at the Cretaceous-Tertiary boundary throughout the world could be taken as evidence that the mass extinction episode at the end of the Cretaceous Period had been caused by the impact of a large asteroid. Further evidence for this has come in the form of microtektites, pollen grains, soot, shocked quartz grains, rippled sandstone, stishovite, amino acids and diamonds. However, the iridium abundance anomaly, together with some of the other features, could also have been the result of extensive volcanism, which is known to have occurred at this time. Volcanism on this scale has to be regarded as a catastrophist mechanism so, throughout much of the past decade, the arguments have been about which of two catastrophist mechanisms, one terrestrial, the other extraterrestrial, played a major role in events at the Cretaceous-Tertiary boundary. Furthermore, it is possible that both were involved, the widespread volcanism being a direct consequence of the impact of a large bolide. What appears to be an enormous impact structure with an appropriate age has been located at Chicxulub, in Mexico. However, the detailed evidence collected over the years indicates that the Cretaceous-Tertiary extinctions were far from instantaneous, suggesting that a mixture of catastrophist and gradualistic factors, or possibly a succession of impacts, perhaps from a shower of comets, might have been responsible. Similarly at other mass extinction horizons, there is evidence that, to a greater or lesser extent, both catastrophist and gradualistic mechanisms, including continental drift, might have played significant roles. The suggestion has been made that there is a periodicity in mass extinctions, and various mechanisms have been proposed which could bring a cluster of comets into the inner Solar System at regular intervals, but none of these has found general acceptance. Nevertheless, one point now firmly established is that the extinction of the dinosaurs at the end of the Cretaceous Period cleared the way for the emergence of mammals, and eventually of ourselves. *Chapter 5* looks in detail at the evolution of humankind, and finds that it was an erratic and unpredictable process. Although "molecular clocks" do not keep perfect time, their development during the 1970s stimulated a re-assessment of fossil evidence, and it is now clear that the human (hominid) line split off from the ape line much later than had been thought. In the subsequent evolution towards /Homo sapiens/, several different hominid species have been identified, but the precise number of species, and the relationship between them, remains a matter for argument. It is still uncertain whether all present day humans are descended from a single population which lived in Africa (or perhaps Asia) in relatively recent times, or whether parallel evolution has occurred in different parts of the world. Another controversial issue is whether the characteristics of each hominid species changed significantly with time. However, it is generally agreed that new species appeared in a rapid fashion, and the disappearance of species was also quite abrupt. This whole process took place against a background of major environmental changes. To some extent these can be explained by continental drift, but catastrophist mechanisms may also have been involved. *Chapter 6* asks, in the light of all of this, where evolutionary theory stands today. Modern developments in molecular genetics have provided no support for Lamarckism, since they have not revealed any mechanism by which specific genetic changes could be produced in direct response to environmental pressures. In contrast, the observed genetic processes were consistent with neo-Darwinism, which maintains that variations arise by factors which are not directly related to environmental pressures, natural selection then determining which variants are most successful in passing their genes on to subsequent generations. Nevertheless, confusion arose because the word "random" was widely used as a shorthand for "not directly related to environmental pressures", and it became increasingly obvious that the production of variants was not random in the true sense of the word, possibly involving laws and levels of organization still to be discovered. Similarly, the relationship between evolution at different levels, from molecules to species and above, needs to be clarified. Thus the Modern Synthesis, if not actually wrong, is far from complete. In any case, when species diversity is high, it is likely that natural selection acts mainly as a stabilizing factor, rather than driving evolution forward. However, when species diversity is low and many ecological niches are vacant, as in the aftermath of a mass extinction, there are much greater opportunities for new variants to become established, and to give rise to further variants. For this reason, mass extinctions, whether resulting from catastrophist or gradualistic mechanisms, or a combination of the two, have had a highly significant bearing on the course of evolution. The characteristic pattern of evolution is of extinctions followed after a pause by the rapid radiation of new species into vacant ecological space. This picture is very different from that envisaged by the founders of the Modern Synthesis: these took the lead from Darwin himself, who wrote in the /Origin/ of evolution proceeding "slowly and progressively ... like the branching of a great tree from a single stem", with extinct species simply being compared to branches which had "decayed and dropped off". In fact, the view of evolution which is emerging, although still consistent with Darwinism, is closer in some respects to that of Patrick Matthew, a contemporary of Darwin. Matthew anticipated Darwin in proposing natural selection as a mechanism of evolution, but saw it operating within a more catastrophist context. That, then, is a summary of /Controversy/, but how did I come to write the book, given that my original specialist research area was biomedical sciences and, in particular, inherited disorders? In fact, the progression has seemed quite natural. Firstly, the biomedical sciences research stimulated an interest in the origin and evolutionary consequence of genetic mutations. Also, the fact that I was an undergraduate student at the same Cambridge College (Christ's) as Charles Darwin, and now have an office in a building named after his grandfather, Erasmus Darwin, has undoubtably provided a stimulus towards thinking about evolutionary topics. The study of evolution in turn led me to take an interest in catastrophism, a process aided by my involvement with the Society for Interdisciplinary Studies (S.I.S,), which provides a forum for the discussion of all aspects of catastrophism and chronology. The outline of the argument presented in /Controversy/ is essentially that followed in a paper entitled 'Catastrophism and Evolution' which I gave at an S.I.S. meeting in Nottingham in 1983. This was published in the /S.I.S. Review/ in 1985. An enlarged, updated version followed several years later, and was issued, under the title /Catastrophism, Neocatastrophism and Evolution /, as a "special publication" of the S.I.S. in 1993. A great deal of new evidence has been produced since then, but the general conclusions reached in both /Catastrophism, Neocatastrophism and Evolution/ and the 1983 paper about overall patterns and mechanisms in evolution, i.e. that extraterrestrial impacts are possible causal agents of mass extinctions, and that radiations of new species generally follow mass extinctions, rather than being contributory causes of them, remain valid today. Indeed, they now have a much more solid foundation, and would receive much wider support than previously. Now that the advances of the 1980s and early 1990s are being consolidated, it seems an appropriate time to present them in some detail, and place them within their historical context. That is what /Controversy/ has attempted to do. If, in the following pages, I can convey to the reader something of the excitement I have experienced in following developments in catastrophism and evolution over the past 20 years, then the effort involved in writing the book will have been very worthwhile. *Trevor Palmer Nottingham May 1998* ------------------------------------------------------------------------ See also: The Society for Interdisciplinary Studies http://www.knowledge.co.uk/sis/ Site Meter ------------------------------------------------------------------------