Chapter 10 The Accidents of Biological History?
Chapter 10
The Accidents of Biological History?
It is widely held, especially by atheist evolutionary biologists, that Darwin’s theory of evolution destroys any notion of divine design or human purpose. Everything in life is a matter of chance, the random outcome of happenstance. This viewpoint is relentlessly propagated in today’s media and is regularly encountered in popular debates.1 After Darwin, we are regularly told, the idea of divine design has to be abandoned. Biological evolution is a random process, with random outcomes. And that’s the end of the matter. It is impossible to speak of “design” in nature after Darwin. Now if you say something often enough, people begin to believe it. But are things really quite as straightforward as this?2
Let’s begin by making a critical distinction between two senses of the word “Darwinism”: Darwinism, considered as a provisional scientific theory about the origins of species, open to revision over time; and Darwinism, considered as a “meta-narrative” or worldview—a grand theory of reality, which is permanently true. The New Atheism treats Darwinism as a meta-narrative, offering a total view of reality.3 Richard Dawkins, for example, suggests that Darwinism is a “universal and timeless” principle, capable of being applied throughout the universe. In comparison, rival worldviews such as Marxism are to be seen as “parochial and ephemeral.”4 For Dawkins and Daniel Dennett, Darwinism provides a “big picture” of reality, from which any notions of transcendence, purpose, design, or divinity have been eliminated. Yet Darwin did not take this view, and neither do those who stick to rigorously scientific analysis. The problems start when enthusiastic New Atheists start tacking on their metaphysical dogmas and try to pass these off as science.
So what if we limit ourselves to what science actually discloses, instead of smuggling in atheistic ideas and trying to invest them with the cultural authority of science. Does this allow us to speak of design or purpose in the natural world—a notion often expressed using the term “teleology”? At first sight, there is a major problem here. After all, Thomas H. Huxley (1825–95)—widely known as “Darwin’s bulldog”—remarked that, having just finished reading Darwin’s Origin of Species for the first time, he was convinced that “teleology, as commonly understood, had received its deathblow at Mr. Darwin’s hands.”5 By “teleology,” Huxley meant “goal-directed behaviour” or “progressing towards a purpose or goal.” Huxley, unlike Dawkins, was not a doctrinaire atheist.6 At this point, however, he seems to endorse Dawkins’s views.
Yet on a closer reading of Darwin, Huxley changed his mind. Darwin’s theories had not eliminated belief in God or belief in teleology. In his 1887 lecture “On the Reception of the Origin of Species,” Huxley forcefully rebuts three common criticisms, each of which he holds to rest on a serious misrepresentation of Darwin’s theory of natural selection.7 Strikingly, some of these misunderstandings recur in recent atheistic manifestos, such as Dawkins’s God Delusion (2006) and Dennett’s Darwin’s Dangerous Idea (1995).
1. “It is said that [Darwin] supposes variations to come about ‘by chance,’ and that the fittest survive the ‘chances’ of the struggle for existence, and thus ‘chance’ is substituted for providential design.” Huxley argues that Darwin has been grossly misunderstood at this point. Darwin was declaring that he did not know what had caused certain things to happen, while locating such events firmly within the context of the laws of causality. Within a Reformed theological framework, for example, “random” can be translated as “non-predictable,” and thus contextualized within a generalized doctrine of divine providence.
2. “A second very common objection to Mr. Darwin’s views was [and is], that they abolish Teleology, and eviscerate the argument from design.” This view, of course, is widely repeated in atheistic writings of the late twentieth and early twenty-first centuries, and it is important to note Huxley’s rather different assessment of the situation. Huxley is quite clear that traditional approaches to teleology, such as that adopted by William Paley, face a severe challenge from Darwin’s account of evolution. Yet the theory of evolution, he argues, bears witness to a “wider teleology,” deeply rooted in the structure of the universe. Darwin forced the redefinition of the idea of teleology, not its abandonment.
3. Finally, Huxley addresses the question of whether Darwin’s theory is anti-theistic. Having shown that Darwin’s theory is not determined by “the belief in chance and the disbelief in design,” Huxley argues that it is obvious that “the doctrine of Evolution is neither Anti-theistic nor Theistic.” Darwinism has not raised any new problems for theism: the problems of relating God to action in the world were already well known. “In respect of the great problems of Philosophy, the post-Darwinian generation is, in one sense, exactly where the pre-Darwinian generations were.”
Huxley’s take on things is quite different from that of writers such as Daniel Dennett and Richard Dawkins, who argue that Darwin destroyed belief in any kind of teleology, sweeping away belief in God as outmoded nonsense.8 Darwin clearly did not believe that himself, and neither did Thomas Huxley, his chief interpreter.
The issue has not gone away. Some Christians have rejected the notion of biological evolution, partly out of concern that it is incompatible with the idea of divine creation and providence. It is certainly true that many evolutionary biologists reject the idea that evolution can be considered in any sense to be teleological. The rejection of any form of teleology achieved the status of an axiomatic truth within neo-Darwinism from about 1970. Evolution was to be understood as an open-ended and indeterminate process, without any predetermined goal. This idea was developed by the French atheistic biologist Jacques Monod (1910–76), who argued that teleonomy had displaced teleology in evolutionary biology.9 In using this term, Monod wished to highlight that evolutionary biology was concerned with identifying and clarifying the mechanisms underlying the evolutionary process. Although the mechanisms which governed evolution were of interest, they had no goal. It was impossible to speak meaningfully of “purpose” within evolution. Needless to say, this idea was seized upon by atheistic apologists.10
Yet the tide has turned in the last decades. It is now widely accepted that some notion of teleology is essential to make sense of what is observed in nature. This does not amount to the endorsement of traditional Christian notions of design or purpose in nature; it does, however, undermine the simplistic slogan “Darwinism defeats teleology,” so characteristic of some recent atheistic writers. Thus the biologist Francisco Ayala argues that the notion of teleological explanation is actually fundamental to modern biology. It is required to account for the familiar functional roles played by parts of living organisms, and to describe the goal of reproductive fitness which plays such a central role in accounts of natural selection. “The use of teleological explanations in biology is not only acceptable but indeed indispensable.”11
Ernst Mayr (1904–2005), widely credited with inventing the modern philosophy of biology, especially of evolutionary biology, concurs. While recognizing some objections to the use of teleological language in biology,12 Mayr notes that biologists continue to use teleological language, insisting that it is methodologically and heuristically appropriate and helpful. As Mayr rightly points out, nature abounds in processes and activities that lead to an end or goal. However we choose to interpret them, examples of goal-directed behaviour are widespread in the natural world; indeed, “the occurrence of goal-directed processes is perhaps the most characteristic feature of the world of living systems.” Mayr thus insists that “the use of so-called ‘teleological’ language by biologists is legitimate.” In many ways, Mayr here echoes the views of Thomas Huxley, set out a century earlier.
So is there a directionality implicit within evolution, whether one chooses to interpret this teleologically or not? This particular phrasing makes it clear that we are posing a legitimate scientific question, not a speculative theological one. The view that evolution is open-ended, without predictabilities and indeterminate in terms of its outcomes, has achieved a dominant position in evolutionary biology. Many writers who adopt the standard Darwinian paradigm argue for the essentially random and contingent nature of the evolutionary process.
The celebrated evolutionary biologist Stephen Jay Gould (1941–2002) insisted that “almost every interesting event of life’s history falls into the realm of contingency.”13 It is pointless to talk about purpose, historical inevitability, or direction. From its beginning to its end, the evolutionary process is governed by contingencies. “We are the accidental result of an unplanned process, … the fragile result of an enormous concatenation of improbabilities, not the predictable product of any definite process.” As Gould famously put this point, using the characteristically 1990s’ analogy of a videotape, if we were to replay the tape of evolutionary history, we would not see the same thing happen each time. “Run the tape again and the first step from prokaryotic to eukaryotic cell may take 12 billion years instead of two.” The influence of contingency is such that what happens is the product of happenstance. “Alter any early event, ever so slightly and without apparent importance at the time, and evolution cascades into a radically different channel.” Gould argues that the role of contingency in biological evolution is so substantial that the tape will disclose different patterns on each individual replay. So is the process of biological development really so subject to the happenstances of history?
Yet Gould’s emphasis on historical contingency is regarded with suspicion by many within the professional community of evolutionary biologists. The Cambridge palaeobiologist Simon Conway Morris, for example, takes a significantly different approach. For Gould, “the awesome improbability of human evolution” is a result of contingency in adaptive evolution. Conway Morris argues against this, challenging the “dominance of contingency.”14
Conway Morris argues that the number of evolutionary end points is limited. “Rerun the tape of life as often as you like, and the end result will be much the same.”15 Life’s Solution builds a forceful case for the predictability of evolutionary outcomes, not in terms of genetic details but rather their broad phenotypic manifestations. Convergent evolution is to be understood as “the recurrent tendency of biological organization to arrive at the same solution to a particular need.”
Conway Morris’s case is based on a thorough and systematic compilation of examples of convergent evolution, in which two or more lineages have independently evolved similar structures and functions. His examples range from the aerodynamics of hovering moths and hummingbirds to the use of silk by spiders and some insects to capture prey. “The details of convergence actually reveal many of the twists and turns of evolutionary change as different starting points are transformed towards common solutions via a variety of well-trodden paths.”16 And what is the significance of convergent evolution? Conway Morris is clear: it reveals the existence of stable regions in biological space. “Convergence occurs because of ‘islands’ of stability.”
The force of Conway Morris’s critique of Gould cannot be overlooked. Though contingency is a factor in the overall evolutionary mechanism, it plays a significantly less decisive role than Gould allows. Evolution regularly appears to “converge” on a relatively small number of possible outcomes. Convergence is widespread, despite the infinitude of genetic possibilities, because “the evolutionary routes are many, but the destinations are limited.” Certain evolutionary destinations are precluded by “the howling wildernesses of the maladaptive,” where the vast majority of genotypes are non-viable, thus precluding further exploration by natural selection. Biological history shows a marked tendency to repeat itself, with life demonstrating an almost eerie ability to find its way to the correct solution, repeatedly. “Life has a peculiar propensity to ‘navigate’ to rather precise solutions in response to adaptive challenges.”
Biological history shows a marked tendency to repeat itself, with life demonstrating an almost eerie ability to find its way to the correct solution, repeatedly.
Even what seems to be a random search process will end up identifying stable outcomes in biological space. Although the means of finding such islands of stability may seem erratic, its outcome is ultimately entirely intelligible. Conway Morris suggests that there is a parallel here with the discovery of Easter Island by the Polynesians, perhaps 1,200 years ago.17 Easter Island is one of the most remote places on earth, at least 3,000 kilometres from the nearest population centres, Tahiti and Chile. Yet though surrounded by the vast, empty wastes of the Pacific Ocean, it was nevertheless discovered by Polynesians. Is this, asks Conway Morris, to be put down to chance and happenstance? Possibly. But probably not. Conway Morris points to the “sophisticated search strategy of the Polynesians” which made its discovery inevitable. The same, he argues, happens in the evolutionary process: “Isolated ‘islands’ provide havens of biological possibility in an ocean of maladaptedness.” It is these “islands of stability” which give rise to the phenomenon of convergent evolution.
The observation that evolutionary biology must explain is the apparent ability of the evolutionary search process to navigate its way to find stable regions of biological space. It is very difficult to see how even a minimalist teleological language can be avoided. Thus Conway Morris suggests, using the image of “Darwin’s compass”:
The view that evolution is open-ended, without predictabilities and indeterminate in terms of outcomes[,] is negated by the ubiquity of evolutionary convergence. The central point is that because organisms arrive repeatedly at the same biological solution, the camera-eyes of vertebrates and cephalopods perhaps being the most famous example, this provides not only a degree of predictability but [also] more intriguingly points to a deeper structure to life, a metaphorical landscape across which evolution must necessarily navigate.18
Ernst Mayr and other philosophers of biology are right to protest against any attempt to impose a predetermined teleology upon a scientific account of the evolutionary process. Yet Mayr’s arguments really only have force when directed against a priori concepts of teleology, which are imported into biology from non-empirical metaphysical systems, whether theist or atheist. Yet it is now widely agreed that some notion of teleology emerges from the study of the evolutionary process itself. Such a teleology is empirical, grounded in a posteriori discernment, not a priori imposition. It is abducted from the observation of the evolutionary process, not deduced from a non-empirical metaphysical system. The term “teleology” is thus rather more elastic than its critics appear to realize. It requires modification in the light of the empirical evidence, not abandonment in response to the somewhat premature and dogmatic demands of those who maintain its inconceivability. This concept of teleology can be mapped onto a Christian framework of understanding, shaped by the core notion of divine providence.
Some Christians will wish to argue for a much more robust statement of the concept of design or the notion of divine providence than those so briefly considered in this chapter. Yet my concern here has been primarily not to articulate a full Christian theology of creation or providence, but to observe how evolutionary biology itself has moved away from the simplistic rejection of apparent purpose or direction within the natural world. Dawkins and Dennett believe that Darwinism tears up the Christian map of reality. That’s one way of looking at things. As the evidence of this chapter makes clear, however, the biological world remains open to interpretation in terms of traditional Christian themes of creation and providence, including the notion of design.19
So what else can be accommodated within the Christian framework? We have focused on contemporary scientific developments, partly because many wrongly believe that science and faith are implacably opposed. But what of other areas of life and thought? In the next few chapters, we shall explore how the Christian map helps make sense of other core areas of human experience. We begin by reflecting on how human history and culture fit into this scheme of things.