Science in Christian Perspective
Burgess Shale and the History of Biology
The King's University College9125 - 50
CANADA T6B 2H3
[From Perspectives on Science and
Christian Faith 47 (September 1995): 159.]
© 1995 Americian Scientific Affiliation
Trilobits found in the Burgess Shale
Stephen J. Gould is a prominent evolutionary thinker and theoretician of biology. In a recent book, Wonderful Life: The Burgess Shale and the Nature of History, he describes the discovery and classification of important fossils from the Canadian Rockies. Subsequent re-classification by three paleontologists led Gould to re-examine the assumption of progress that underlies most phylogenetic theories. Evolution, Gould suggests, is not a linear progression toward present species, with the most successful at the top of a cone of increasing diversity (or toward a human apex). Rather, the history of life can be characterized as a tree or a bush, because not all branches reach the present: some animal types have become extinct due to exigent conditions. The history of biology resembles phylogenetic development postulated by Gould. Although not all biological theories persist to the present, the history of biology is nevertheless often presented as linear progress toward present views and theories. However, like an investigation of extinct animal types, an understanding of abandoned scientific theories can enlarge and enrich our contemporary view of science.
My Canadian Rockies trail guide states: "The beauty of Emerald Lake was considered grand enough to adorn the back of the $10 bill for many years and it's certainly grand enough for a rewarding hike." Emerald Lake is in Yoho National Park, British Columbia, Canada, a park famous for this lake and for the Burgess Shale, located about 5 km from the town of Field and within view of Emerald Lake.1
Charles Doolittle Walcott discovered the Burgess Shale in 1909; he, together with aides and members of his family, returned to it during several summers to collect fossils, right up to 1917. Walcott was an influential scientist and Secretary of the Smithsonian Institution in Washington, D. C. The story of Walcott's collection, and its subsequent re-examination by three scientists is brilliantly retold by Stephen J. Gould in his book Wonderful Life: The Burgess Shale and the Nature of History.2
Gould's book, which has been well-received in the biological community, forms the basis of the first part of this article. In this book, and in other writings, Gould has attempted to formulate theories that describe the tempo and mode of evolution. These theories provide an alternative to the linear theories of biological development that have predominated for many years. To compare Gould's views with the history of biology reveals fascinating parallels. In this history, theories of linear development have also held sway. Here, too, there is an increasing realization that not all biological theories survive to the present.
The Walcott Fossils Re-examined
Gould describes the initial classification of the Burgess fossils, stating: "Walcott proceeded to misinterpret these fossils in a comprehensive and thoroughly consistent manner arising from his conventional view of life: In short, he shoehorned every last Burgess animal into a modern group, viewing the fauna collectively as a set of primitive or ancestral versions of later, improved forms. Walcott's work was not consistently challenged for more than fifty years."3Gould then recounts how Harry Whittington of Cambridge University, and two graduate students, Derek Briggs and Simon Conway Morris, re-examined the Burgess fossils. They decided that the way Walcott had classified the fossils was entirely wrong. Their work has been of great interest to animal systematists everywhere.
Much of Gould's book is dedicated to a description of the Burgess fossils. These fossils are postulated to be the result of the "Cambrian explosion," about 500 million years ago. The nature of the Cambrian explosion, one of Darwin's more vexing problems, has been discussed by many authors in numerous recent articles.4 Some of the Burgess fossils are striking, unlike any invertebrates one is likely to encounter today. They are as foreign to living animals as dinosaurs are, but they are much more difficult to classify. At least dinosaurs can be recognized as reptiles!
The names of the fossils are also striking: Marella, Yohoia, Opabinia, Amiskwia, and Hallucigenia, are some of the names given to organisms discovered in the Burgess shale (Fig. 1). The name Hallucigenia speaks for itself.5 Opabinia, another remarkable animal, had five eyes and fed itself with a segmented, flexible, frontal appendage, much like a vacuum cleaner hose. When Whittington first described this creature at a British scientific conference, his illustration of Opabinia was greeted with laughter, which he did not know how to interpret. The conclusion reached by various scientists is that the Burgess Shale contains some 15 to 20 organisms so different one from the other, and so unlike anything now living, that each ought to rank as a separate phylum. Over fifteen new phyla; that is quite a find!
For many years Gould has had a double career in biology. In addition to his biological work, he has been the writer of successful columns in Natural History. Gould has written many influential books, some of which have included these columns.6 Wonderful Life, which appeared in 1989, also displays Gould's considerable writing skills.
In one way, Wonderful Life is an unselfish book. Gould describes work on re-classification of fossils that he neither found nor re-classified. But there is method in his madness, for Gould is also known for his efforts to re-write some aspects of evolution theory. Faced with the fact that some invertebrate creatures appear in the fossil record, without change, in layer upon layer, Gould and Niles Eldredge suggested, in 1977, that "Stasis is data" and posited their theory of "punctuated equilibrium."7 They characterized evolution as consisting of long periods of little change, punctuated by relatively short periods of rapid change. It goes beyond the scope of this article to evaluate the punctuated equilibrium theory; it can be said, however, that the central claims of punctuated equilibrium have largely been accepted by the paleontological community.
In Wonderful Life, Gould takes these theories one step further. The evolutionary process, he argues, cannot be characterized as a linear path that leads toward humankind as the inevitable goal. Standard iconography (i.e., depictions of evolutionary progress in animal groups) must be revised because it is based on an outdated view that presents evolution as the inevitable climb up a ladder that has the human species at its apex.8 Nor do the products of the evolutionary process all persist until now, Gould goes on to say. Instead of a cone, the phylogenetic scheme should be presented as a bush, in which not all branches reach the present (Fig 2).9 Gould suggests that survival of some biological organisms is determined by contingency ("luck," or conditions that happened to prevail at the time).10 In all of this, Gould is attempting to re-write current theories of natural history. He is proposing a new model for the tempo and mode of evolution. While creation scientists have often presented this as a sign of the breakdown of evolution theory, Gould characterizes himself as an evolutionist, and he is very critical of the creationist movement.11
Gould's Views and the History of Biology
In making the connection between fossils and the history of the discipline, the following passage, from Hays (1973), is helpful:
In 1774, young men all over Europe began wearing blue coats, yellow waistcoats and boots. This was the result of a literary success, The Sorrows of Young Werther, which Goethe wrote at the age of twenty-five, when he was entirely a creature of undisciplined feeling. Werther worshiped nature, devoted himself to an orgy of sensibility, and finally, when frustrated in love, committed suicide.12
Johann Goethe wrote literature, but he also considered himself a biologist. His studies on plant morphology and on vision were well-known, especially at the time they were written. Today we would say that the work was largely theoretical and highly speculative. In fact, Hays suggests, "On the whole, Goethe's specific contributions to biology were wrong or else had been anticipated long before."13 What are we to make of him? Some history of biology texts skip Goethe, and German romanticism altogether!14 Yet this influential school should be discussed and studied, much as are fossils in phyla that no longer have living representatives today.
In an article provocatively entitled "Should the History of Science be Rated X?" the author, Stephen G. Brush states:
[A]nother issue now being debated by historians of science [is] the so-called Whig interpretation of history. This phrase was introduced about 40 years ago by historian Herbert Butterfield to characterize the habit of some English constitutional historians to see their subject as a progressive broadening of human rights, in which good "forward-looking" liberals were continually struggling with bad "backward-looking" conservatives. In the last few years, historians of science have applied the term to the accounts of scientific progress that tended to judge every scientist by the extent of his contribution toward the establishment of modern theories. Such an interpretation looks at the past in terms of present ideas and values, rather than trying to understand the complete context of problems with which the earlier scientist himself had to work.15
Butterfield, in a passage that must have interested Brush, states:
[The] whole fabric of our history of science is lifeless and its whole shape is distorted if we seize upon this particular man in the fifteenth century who had an idea that strikes us as modern, now upon another man of the sixteenth century who had a hunch or an anticipation of some later theoryCall as if one were making a catalogue of inventions or of maritime discoveries. It has proved almost more useful to learn something of the misfires and the mistaken hypotheses of early scientists, to examine the particular intellectual hurdles that seemed insurmountable at given periods, and even to pursue courses of scientific development which ran into a blind alley, but which still had their effect on the progress of science in general.16
Thus we can characterize the Whig interpretation of the history of science as the history of science as we perceive it today. This view has been characterized: "Our ancestors are climbing up a mountain on whose summit we now stand." One could also conclude that the Whig interpretation of history resembles the linear (Lamarckian) view of biological evolution. This view is, in turn, closely related to nineteenth century ideas of progress that were prevalent at the time of Lamarck.17
If Brush and Butterfield are correct, and I believe that they are, then Goethe is worth studying not only because his followers quickly jumped from speculative theorizing to detailed laboratory science18 Goethe and his time period are also of interest for their own sake. We can conclude that the history of science is not an account of the steady progression of theories toward the present but also includes theories that are no longer held. Like Gould and his fossils, we should not interpret the past only on the basis of the present. What is historically important will have to be deduced from the study of a given period or school of thought.
Gould suggested that some species have survived to the present because of exigency, that is, conditions that prevailed during the existence of the organism. While "luck" or other irrational factors do not determine survival of biological theories in the same way, non-logical factors can influence the survival or acceptance of such theories.19
While we question the nineteenth century's exultation of progress (a strain not absent from the present science establishment), we can recognize that there may be improvements in scientific theory over time. Progress is a loaded term, but if one stresses change without improvement, one would arrive at a purely historicistic or relativistic position, not a very acceptable alternative. Investigators examine nature; they are not free to postulate theories as they see fit, because these theories do have to be tested with further observations. At some time a theory can become problematic because it does not answer all questions satisfactorily, or does not explain all phenomena satisfactorily, and scientists seek to find theoretical replacements. It then becomes the historian's task to determine why some theories were held at one time, and why they were later rejected.
Thus, the growth of science can be likened to a version of the theory of evolution, where the developmental process is no longer seen as a steady progression towards the present. On the basis of new theories, and the Burgess fossil discoveries, the shape of the phylogenetic tree is postulated to be different, possessing branches of animal phyla that have no relationship to present-day animals.
In the theories of Thomas Kuhn, a philosopher often cited, scientific revolutions occur when one scientific theory replaces another.20 This is reminiscent of how, in natural history, some life forms replace others. The Strong Programme, associated with the Edinburgh school and author David Bloor, goes one step further by suggesting that scientific theories reflect the social interests of those who promote them.21 P. Bowler, in his book The Mendelian Revolution, has attempted to show this for theories of genetics.22
We may not be accustomed to the picture of science and scientists which emerges from our examination. Science is not a body of thought which grows, slowly but surely, until the present enterprise and body of opinion emerges. Science also contained theories that we no longer hold. And scientists are not the disembodied, objective, investigators they are sometimes made out to be. They pursued avenues of investigation that now strike us as odd or as dead ends, like fossils in the Burgess Shale. Opinions on how science grows vary widely in today's history of biology, and in the philosophy of science.
Can textbooks in biological subdisciplines, such as genetics, microbiology, or comparative physiology, be expected to describe to students theories and views that are no longer held? While current theories will receive most attention, students should also obtain an understanding of the roots and context of the discipline. If this does not occur, biology students may get a more naively positivistic, linear view of the growth of the discipline than is desirable. The students' understanding of the development of biology can be enhanced by colleges and universities offering history of biology or history of science courses. At liberal arts institutions, particularly Christian ones, such courses also offer an opportunity to examine foundational issues in biology. It is regrettable that few suitable history of biology textbooks are available.
A related and often decried problem is the cursory way in which textbooks describe the development of the disciplines. Cells, first named by Robert Hooke; genera and species, first mentioned by Aristotle, and microscopes, first used by van Leeuwenhoek, often complete the history of a discipline such as microbiology. As such, history consists of tracing the origin of a few key words and phrases that we still use today. Here, too, the post-secondary curriculum can do much to correct wrong impressions. One would hope that such short historical descriptions would become the fossil of an extinct species, replaced by a more succesful, living treatment of the subject.
I would like to thank Maria Cook for giving me Gould's book as a present, and Natalie Cook and my colleagues at The King's University College in Edmonton for helpful suggestions during the writing of this article. I also thank Keith B. Miller for relevant literature references.
1Dodd, J., and Helgason, G., 1988. The Canadian Rockies Access Guide, (Edmonton, Canada: Lone Pine Publishing, 1988), p. 236, p. 12.
2Gould, Stephen J., Wonderful Life: The Burgess Shale and the Nature of History, (New York: W. W. Norton & Company, 1989).
3Gould, S.J., 1989, Wonderful Life, p. 24.
4See, for example, Kaveski, S. and Margulis, L., "The `Sudden Explosion' of Animal Fossils About 600 Million Years Ago: Why?" The American Biology Teacher, 45(2) (1983), pp. 76-82; Knoll, A. H., "End of the Proterozoic Eon," Scientific American, Nov. 1991, pp. 64-73; Levinton, J. S., "The Big Bang of Evolution," Scientific American, Nov. 1992, pp. 84-91; Conway Morris, S., "The Fossil Record and the Early Evolution of the Metazoa" Nature, Jan. 21, 1993, pp. 219-225 and "Ediacaran-like Fossils in Cambrian Burgess Shale-type faunas of North America" Palaeontology 36 (1993) pp. 593-635; Jun-yuan, C., and Erdtman, B. D., "Lower Cambrian Fossil Lagerstatte from Chengjiang, Yunnan, China: Insights for Reconstructing Early Metazoan Life" in Simonetta, A. M. and Conway Morris, S. (eds.), The Early Evolution of Metazoa and the Significance of Problematic Taxa, (Cambridge: Cambridge University Press, 1991). Gould has discussed the Cambrian explosion in his chapter, "Is the Cambrian Explosion a Sigmoid Fraud?" in Ever Since Darwin, (New York: W. W. Norton & Company, 1973) pp. 126-133.
5See also: Beardsley, T., "Weird Wonders," Scientific American, June, 1992, pp. 30-34. Gould, S. J., in "The Reversal of Hallucigenia," Natural History, Jan. 92, pp. 12-20, discusses, and cites literature on whether Hallucigenia is described upside down in previous literature.
6The books based on articles in Natural History are: Gould, S. J., Ever Since Darwin (1973), The Panda's Thumb (1980), Hen's Teeth and Horse's Toes (1983), The Flamingo's Smile (1985), An Urchin in the Storm (1988), Bully for Brontosaurus (1991), Eight Little Piggies (1993), all published in New York by W. W. Norton & Company. Other books are: Gould, S. J., Ontogeny and Phylogeny, (Cambridge, MA: Belknap Press of Harvard University Press, 1977); The Mismeasure of Man, (New York: W. W. Norton & Company, 1981); Time's Arrow, Time's Cycle, (Cambridge MA: Harvard University Press, 1986). As far as I can ascertain from my slightly imperfect collection of ASA publications, no book of Gould's has been reviewed in Perspectives or the ASA Journal, which is surprising and regrettable.
7Gould, S. J., and Eldredge, N., "Punctuated Equilibria: the Tempo and Mode of Evolution Considered," Paleobiology 3 (1977), pp. 115-151.
8Such a linear view, based on Lamarckism, has been discussed in several of P. J. Bowler's books. See, e.g.: The Eclipse of Darwinism: Anti-Darwinian Evolution Theories in the Decades around 1900, (Baltimore, MD: Johns Hopkins University Press,1983), ch.4; Theories of Human Evolution: A Century of Debate, 1844-1944, (Johns Hopkins University Press, 1986); The Non-Darwinian Revolution: Reinterpreting a Historical Myth, (Johns Hopkins U. Press, 1988); Charles Darwin: the Man and his Influence, (London: Basil Blackwell Inc., 1990), ch. 9. See also note 15.
9Gould, S. J. 1989, Wonderful Life, p. 46.
10L. M. Van Valen discussed contingency in a review of Gould's "Wonderful Life: How Far does Contingency Rule?" Evolutionary Theory 36, pp. 47-52.
11Gould, S. J., 1983, Hen's Teeth, p. 260.
12Hays, H. R., Birds, Beasts, and Men, (Baltimore, MD: Penguin Books Inc., 1973), p. 205. Despite its dated title, this book avoids some of the pitfalls described in the second half of this article, i.e. it describes theories and schools of thought that are no longer followed (e.g. German Romanticism), but that are of historical importance.
13Hays, H. R. 1973, Birds, Beasts, and Men, p. 207.
14See, e.g., Gardner, E. J., History of Biology, (Minneapolis, MN, Burgess Publ. Co., 3rd edition, 1972).
15Brush, S. G., "Should the History of Science be Rated X?" Science 183, March 22 (1974) pp. 1164-1172. For a different view see Harrison, E., "Whigs, Prigs and Historians of Science." Nature 329, Sept. 17, (1987) pp. 213-214.
16The quotation is from Butterfield, H., The Origins of Modern Science, (New York: The Free Press, Revised Edition, 1957) pp. 8-9. Butterfield's theories on the Whig interpretation of history are described in: Butterfield, H., The Whig Interpretation of History, (London: G. Bell & Sons, Ltd, 1950). Butterfield is a Christian historian, well worth reading. C. T. McIntyre has edited some previously unpublished articles of Butterfield in a more recent book, and has included a biographical description of Butterfield's life in the introduction: Herbert Butterfield, Writings on Christianity and History, C. T. McIntyre, Ed. (Oxford University Press, 1979).
17See note 9 for P. J. Bowler's books that deal with linear, teleological, Lamarckian views of evolution. In a recent book, Bowler relates this more explicitly to nineteenth century views of progress: Bowler, P. J., The Invention of Progress: The Victorians and the Past, (London: Basil Blackwell, 1989). See also Gould, S. J., 1977, Ontogeny and Phylogeny. A standard work on the idea of progress is Bury, J. B., The Idea of Progress; an Inquiry into its Origin and Growth (New York, Dover Publications, 1932); see also Cate, C., "How We Learned to Believe in Progress," Horizon 15 (3) (1973) pp. 105-111. For a Christian view on the topic see Wells, R. A., History Through the Eyes of Faith (San Francisco: Harper & Row Publishers, 1989), and Wilcox, D. L., "Three Models of Making: Prime Mover, Craftsman and King : Alternate Theistic Frameworks for Teaching Origins" Perspectives on Science and the Christian Faith 39(4), (1987) pp. 212-220.
18Consider, for example, the work of biologists described in Hays, H. R., 1973, Birds, Beast, and Men, Ch. 18.
19This is discussed in the article by S. G, Brush cited in 15.
20Kuhn, T. S., The Structure of Scientific Revolutions, (Chicago: The University of Chicago Press, 1962). For a review see H. Cook, Journal of the American Scientific Affiliation, March, 1973, pp. 34-38.
21Bloor, D., Knowledge and Social Imagery, (London: Routledge and Kegan Paul, 1976).
22Bowler, P. J., The Mendelian Revolution: The Emergence of Hereditarian Concepts in Modern Science and Society, (London: Athlone Press, 1989) pp. 16-18; see also his more recent book Charles Darwin: The Man and his Influence, (Oxford: Basil Blackwell, 1990).