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THE Darwinian theory of evolution is now widely received among scientists. The details of the theory are still hotly debated but the theory itself has received an enormous explanatory power since the first time it was formulated a century and a half ago. The scientific debates occur henceforth inside the frame of Darwinism (at times called “neo-Darwinism”).
The most obvious result of the Darwinian enterprise is that we have entered a global evolutionary view of the world. It is not only the case in the living world. Even matter in the so-called “inert” sense of the word is seen to be in the process of becoming. Evolutionary biology is akin to Big Bang cosmology. These two major theories of contemporary science are more “historical” than “physical”. To a certain extent they escape the traditional criteria of scientific proceeding. They cannot be falsified by repeatable experiments for the simple reason that repetition does not occur in history. History is a process that brings something new in time. In this respect Darwinism has not only brought a new vision of the natural world, but also a new perspective on how science is practised.
These elements explain why the Darwinian theory was so vividly discussed in society at large at the time it was published. Even if it is now accepted among scientists it remains a topic of contest in certain circles which do not easily accept this profound mutation “from certainty to uncertainty”.(1)
This article will present four topics. First I will give a reminder of the main components of the Darwinian vision of the living world. The second topic will deal with the scientific reception of Darwinian theory, exhibiting some obstacles in the first period. These obstacles are linked with a certain vision of science as already noticed. The third point will concern religion. In the general public and the media the idea is widely spread that Darwinism has swept aside the claims of religion. The picture is more complex. It would be more right to speak of a mutation inside the religious vision of the world. The last topic will focus on the vision of humankind in relationship to the natural world. In sharp contrast with the traditional western anthropocentrism, the Darwinian theory increases the inclusion of humanity within nature. This leads to a new vision of the human person.
Elements of the Darwinian vision of life
Charles Darwin was not the first naturalist to think that organic evolution might have occurred. Some of the component elements of his theory had been separately proposed long before the publication of On the Origin of Species in November 1859. One important step was the publication of Charles Lyell’s Principles of Geology (1830), which represents a “turning point in modern geology”.(2) Lyell maintained the “uniformitarian” theory already proposed per James Hutton (1795) in opposition to the “catastrophist” theory held by the great French paleontologist Georges Cuvier. This so far prevailing theory postulated a series of “catastrophic” events leading to the extinction of species and creation of new ones. For Lyell the mere operation of natural causes through great spans of time is responsible for the geological situation we can observe. We need no more “divine” (i.e. extra natural) interventions to explain away the natural phenomena. Long and slow working natural causes are enough.
If geology was firstly led by “catastrophism”, botanic and zoology were under the sign of fixity. The great diversity of individual organisms could be reduced to a certain number of permanent “species”. In the middle of the eighteenth century the Swede Carl Linnaeus had worked out the first comprehensive system of classification still in use today. There are permanent distinctions among species. At least one can accept individual variability (among dogs one observes different breeds inside the one species) and extinctions from time to time. For Linnaeus and practically all the scientists of the time, permanency is, as in the physical world, the condition of a “scientific” picture of reality.
This fixity of species was challenged by Jean Baptiste Lamarck. In his Biological Philosophy (1809) he proposed the idea of unlimited organic changes. An animal’s organ develops through habitual use and these acquired modifications are inherited and passed to the next generation. Lamarckian theory remained contested for some time. Indeed it failed to perceive the importance of the extinction of species, whose evidence was more and more at hand. At the time the newly discovered fossils did not exhibit continuous variations but series that began and ended abruptly. Another difficulty was the acquisition of inheritable characteristics of individual organisms. Some of them cannot be acquired during its life.
The idea of stability of biological forms needs to be underlined. It long dominated Western thought. Two main sources can be proposed. One can think of a religious influence: each type of being was created by God in the beginning (or at least after every “catastrophe”). As far as it is created by God it should not change, except for individual variations that do not modify the “archetype”. Another cause, no less influent, is the traditional (i.e. Aristotelian as well as Platonic) conception of science: all individual beings are embodiments of eternal “essences”. This essence needs not to be fully realized in an individual organism. It constitutes the “ideal” type or the goal (final cause) this organism strives to get: “natural processes [are] incapable of any truly creative act”.(3)
The Darwinian Origin of Species presented a vast amount of evidence for evolution and it proposed a mechanism by which it could give rise to the vast variety of life forms. In this respect it is not only a once again formulated “transformist” intuition. It brings out new material to support the hypothesis. “Darwin was a highly creative thinker who synthesized a number of key insights, some derived from his scientific work and others from currents circulating in his cultural environment.”(4) The theory combines several ideas: (a) Random variations. That does not mean that these variations have no cause (we know more now thanks to genetics), but the causes of the variations do not play any role in the global evolutionary process: “variation was certainly caused by something (later identified as genetic mutations), but it was not aimed in any one direction”.(5) (b) The struggle for survival. Some variations give a slight advantage in the competition for existence in a given environment. (c) The survival of the fittest. The individuals having such an advantage will live longer and have more descendants than the others in that environment. Thus some variations are “selected” by the environment and after a long period of time give rise to new species.
The result of the process is unpredictable. There is no more a series of isolated “special creations” nor a “step-ladder” view of evolution, but the scheme of a “branching-tree”. In the Darwinian view, evolution is not to be conceived from the model of embryonic development as a predictable unfolding of possibilities. The variations occur in an undirected way before being selected by the environment. The very word of evolution is misleading, since it usually refers to the unfolding of an embryo in which the whole process and its goal are already predetermined. This is the reason why Darwin was first reluctant to use the word.
The Darwinian theory comes from an extensive study of nature, a study of artificial breeding techniques (selection of different attributes in pigeons, dogs and horses), a wide reading (for instance Lyell’s Principles of Geology with its insistence on processes of gradual change over very long periods of time and Malthus’ Essay on the Principle of Population, claiming that there is a struggle for resources), a wide correspondence with practically the whole scientific world of the time. Darwin’s work exhibits a fruitful interplay of observation and theory. It is not only a collection of data that can give birth to a new theory unless it is sustained by a hypothesis able to unify the data. On the contrary an idea, as original it...
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1. Cf. F. David Peat, From Certainty to Uncertainty. The Story of Science and Ideas in the Twentieth Century, Washington, John Henry Press, 2002.
2. Ian G. Barbour, Religion and Science, San Francisco, Harper and Collins, 1997, p. 50.
3. Peter Bowler, Monkey Trials and Gorilla Sermons, Cambridge, Harvard University Press, 2007, p. 51.
4. Peter Bowler, “Darwin’s Originality”, Science, 323, January 9th 2009, p. 223.
5. Id., p. 224.
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François EUVÉ, a Jesuit since 1983, after graduating at the Superior Normal School of Cachan, France, obtained the aggregation in Physics (of plasmas) in 1976 and a PhD in Catholic Theology in Centre Sèvres, Paris, in 2000. He first taught Theology in the Saint Thomas Institute, Moscow (1992-1995), and since 1997 in Centre Sèvres, the Jesuit Theology Faculty of which he was appointed Dean in 2005. His numerous publications include Darwin et le christianisme. Vrais et faux débats [Darwin and Christianity, real and false debates], Paris, Buchet-Chastel, 2009; Science, foi, sagesse. Faut-il parler de convergence? [Science, faith, wisdom: is there any convergence?], L’Atelier, 2004; Ecclesiology [a course, in Russian], Moscow, Saint Thomas College Editions, 1996. He also contributed in many scientific or theological collective publications and has written many articles in various scholarly publications in the scientific and theological fields.
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| Issue 6.4 |
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World Mutation or
Epochal Challenge?
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