Evidence for God: Design (Part 3 –Life on Earth)

David Glass and Graham Veale
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In Part 1, we considered the order of the cosmos as expressed in the laws of physics as evidence for God, while in Part 2 we looked at fine-tuning. Here we focus on the existence of intelligent life. As in the previous cases, the contention is that theism provides the best explanation for the life we observe on Earth, including the existence of intelligent life.

At the outset, it is worth pointing out that we are not proposing God as a scientific explanation of intelligent life, but rather as a personal explanation. That is, we are not attempting to identify the mechanisms God used to bring about intelligent observers. Instead, we are arguing that intelligent life is much less surprising in a universe created by God than in an atheistic universe. The question is whether the existence of intelligent life provides additional evidence for God over and above that provided by the order in the universe and fine-tuning. In other words, after these other factors are taken into account, is the existence of intelligent life better explained by theism than by atheism?

Just as there is order expressed in the laws of physics, there is a great deal of order in the biological domain. In fact, this is a gross understatement. The more scientists have learned about living organisms, the more they have come to realize just how incredible the order and complexity is. Whatever view one takes on design, there can be no denying the fact that there is a breath-taking degree of order and complexity in the biological world. From a single cell, where the digital information for life is encoded in the DNA and where a whole array of sophisticated molecular machines carry out the processing required for the cell to function properly, to the human brain which is frequently described as the ‘most complex object in the universe’, order and complexity are ubiquitous.  To emphasize the point, here is how Richard Dawkins describes mitochondria:

Mitochondria are found not just in photocells, but in most other cells. Each one can be thought of as a chemical factory which, in the course of delivering its primary product of usable energy processes more than 700 different chemical substances, in long, interweaving assembly-lines strung out along the surface of its intricately folded internal membranes … Each nucleus … contains a digitally coded database larger, in information content, than all 30 volumes of the Encyclopaedia Britannica put together (Dawkins, 1986, pp 17-18).

Even though Dawkins is highly critical of design arguments, when commenting on William Paley, a leading defender of design in the eighteenth century, he comments, ‘when it comes to complexity and beauty of the design, Paley hardly even began to state the case’ (Dawkins, 1986, p. 21) So there’s no doubt about the evidence, but what about the explanation for it? Many think that there is a perfectly good explanation which removes the need for God: the theory of evolution.

Our view is that debates about evolution can be a distraction from the central issue which is whether intelligent life was designed by God. Once that question is answered, it is less important to what process [1] was involved in the production of intelligent life. Suppose humans discover some kind of complex machine on another planet. It would be entirely reasonable to infer the existence of an intelligent agent who designed the machine even if we had no idea about the process that had been used. No doubt it would be interesting to know the process too, but that’s a distinct question; there could be a wide variety of processes the intelligent agent might have used. Similarly, in the case of intelligent life, the issue of design is distinct from the issue of process and so the existence of a process doesn’t settle the issue one way or the other.

In order to assess the case for design in this case, we have to ask how likely it is that the types of life that we observe on Earth would come into existence given only unguided physical processes. This should be compared to the likelihood of such creatures given theism. There are a number of reasons to think that unguided, physical processes cannot account for many features of the living world.

Following Darwin Up Mount Improbable?

The theory of evolution by natural selection can be outlined very simply. All living things descended from one form of life, which arose four billion years ago. There was some variation in each new generation of creatures. Some variations allowed a few individuals to reproduce more successfully than others, and their offspring inherited these advantages. Yet there are not enough resources for everyone, so organisms without beneficial variations did not survive. Over time beneficial variations accumulated in lineages, and this led to large changes in the members of a population. Eventually new species formed as populations split into groups that could no longer interbreed(Garvey, 2007, pp.1-15).  Crucially, the mechanisms involved were normal physical and chemical processes. Biology need only appeal to physical events, making it as ‘scientific’ as Physics or Chemistry.

For Richard Dawkins, evolution by natural selection does more than give an unified account of the history of life on earth, or tell us how new species form. For Richard Dawkins the central problem of evolutionary biology is the existence of complex adaptation (Sterelny, 2007, p.8). How could intricately complicated adaptations like the vertebrate eye exist unless they were designed? It is inconceivable that a fully formed eye could form by accident: it simply has too many parts which must be arranged in the correct way. But Darwin showed that design and purely random ‘all-at-once’ events were not the only options. The evolution of the eye, for example, did not occur all at once. It happened gradually, over thousands of generations.

Dawkins likens the combination of “perfection and improbability that is epitomised in eyes”(Dawkins, 1996, p.68) to mountaineers at the bottom of the “towering, vertical cliffs” of “Mount Improbable” The heights seem unattainable.  However, the climbers are too ambitious.

So intent are they on the perpendicular drama of the cliffs they do not think to look round the other side of the mountain. There they would not find vertical cliffs…but gently inclined grassy meadows, graded steadily and easily towards the distant uplands.” The sheer height of Mount Improbable is only daunting if you attempt to leap it in a single bound. “If one simply takes enough time on the gently sloping paths the ascent is only as formidable as the next step” (Dawkins, 1996, p.64-65).

A simple light-sensitive spot on the skin of some ancestral creatures gave them an advantage by allowing them to detect and move towards light sources, thereby aiding photosynthesis. They passed this advantage to their descendants. Then, in one or more descendants, random changes created a depression in the light-sensitive patch, effectively placing it in a little ‘cup’, which enabled better detection of the direction of the light. More random changes in subsequent descendants would cause little ‘pin holes’ to develop over the cup, greatly increasing resolution and imaging. More and more specialised cells would evolve over time until we have the camera type eyes characteristic of vertebrates (Dawkins, 1996, 136-147).

Only a little ‘luck’ was needed at each stage of the eye’s development, and each ‘improvement’ of the eye was preserved by natural selection. As Dawkins describes it, the process of evolution by natural selection explains away the appearance of design in the world by “taking what looks to be an immense amount of luck – the amount of luck needed to make an eye where there was no eye, say – and splitting it up into lots of little pieces of luck, each one added cumulatively to what has gone before.” (Dawkins, 1996, p.81)

The Likelihood of Life as We Know It

Dawkins’ appeal to the gentle slopes of Mount Improbable is suspect. Perhaps only a little luck is needed to move from one stage to the next up the gentle slope. But that does not mean that it only takes a little luck to get from the base to the summit. The probabilities are independent and therefore multiply. As Elliott Sober (2003) has pointed out in another context:

Imagine a long sequence of evolutionary transitions…from the prebiotic soup all the way to shopping. Even if each  transition in this chain — from the first to the second, from the second to the third, and so on – were  highly probable, it would not follow that the transition from the first to the last is highly probable. The  problem is that probabilities multiply; multiply a big probability like 9999/10000 by itself enough times  and you obtain a probability that is very small indeed.”

Furthermore, Dawkins concedes that some of the events in the history of life on Earth were exceedingly improbable (Dawkins, 2006, p.189). The origin of life is incredibly improbable because the different pre-biotic building blocks can only be assembled in radically different environments. It is incredibly improbable that the various chemicals, minerals and catalysts would ever be found together in the same environment; even then, something would need to cause them to react in the correct way (Conway Morris, 2003, pp.44-69). Dawkins also concedes that the emergence of the first Eukaryotic cells might even be more improbable than the origin of life (Dawkins, 2004, p.602).

Nick Lane explains the importance of Eukaryotic cells for the history of life on our planet: “never-ending natural  selection, operating on infinite populations  of bacteria over billions of years, may never  give rise to complexity. Bacteria simply do not have the right architecture…” (2012, p.37). Cells need lots of energy per gene, and making a protein from a gene is an energy intensive process. This is

a tremendous  barrier to growing more complex, because  making a fish or a tree requires thousands  more genes than bacteria possess. So how did eukaryotes get around this  problem? By acquiring mitochondria. About 2 billion years ago, one simple  cell somehow ended up inside another.  The identity of the host cell isn’t clear, but  we know it acquired a bacterium, which  began to divide within it. These cells within  cells competed for succession; those that  replicated fastest, without losing their  capacity to generate energy, were likely to  be better represented in the next generation….

You can think of mitochondria  as a fleet of helicopters that “carry” the DNA  in the nucleus of the cell. As mitochondrial  genomes were stripped of their own  unnecessary DNA, they became lighter and  could each lift a heavier load, allowing the  nuclear genome to grow ever larger. These huge genomes provided the genetic  raw material that led to the evolution of  complex life. Mitochondria did not prescribe  complexity, but they permitted it. It’s hard to  imagine any other way of getting around the  energy problem – and we know it happened  just once on Earth because all eukaryotes  descend from a common ancestor (Lane, 2012, p.37)

Indeed, elsewhere Lane refers to the emergence of eukaryotic life as “a freak event that changed the world” (2010, p.39). Other events were not so improbable, but still reasonably unlikely. For example, Dawkins draws attention to the importance of segmentation for evolution (Dawkins, 2004, pp 622-624). Segmentation is the train-like modularisation of the body. It helps to explain the increase in organised complexity and taxonomic diversity because a lineage that manages to evolve a segmented body plan is immediately able to evolve a whole range of new animals by altering segmental modules, all along the body. But, initially, segmentation was not beneficial:

   …when segmentation originated, there must have been a mutational transition straight from unsegmented parents to a child with two (at least) segments. It is hard to imagine such a freak surviving, let alone finding a mate and reproducing, but it evidently happened because segmented animals are all around us.” (Dawkins, 2004, p.623)

On Dawkins’ account, the evolution of segmentation depended on some luck – the chance survival of “freak” animals, who manage to survive and reproduce despite having the disadvantage of useless segments.  So the increasing organised complexity and diversity of life on earth depends on numerous evolutionary transitions, each of which can be assigned an independent probability. Let us allow that many events had a high probability. Some important events, like the evolution of segmentation, had a fairly low probability.  And others – like the origin of life and the evolution of the first eukaryotic cells – had a very low probability. Multiply those probabilities together and you get a very low probability indeed.

It is also worth noting that the whole process of evolution by natural selection depends on a high degree of order and structure. Dawkins points out that evolution depends on replicators: structures which cause copies of themselves to be made; each acts as its own template for copying (Dawkins, 1989, pp.15-20). The copying system must allow for a little variation in each new generation; this allows a population of variants to come into existence. Yet the copying process must also be very reliable – otherwise beneficial variations would not be preserved. Furthermore, Natural selection requires more than variation and very reliable replication. The replicators must exist in an environment in which they compete for resources. Finally, to explain the taxonomic diversity and organised complexity of our world, these replicators must be able to combine to form vehicles  - that is, structures ( for example, organisms) which work to propagate their replicators (Dawkins, 1989, p.254).

It is remarkable that such a replication process is possible. Evolution can only take place because the laws of physics and chemistry allow inorganic molecules to combine to form organic molecules which can become replicators of the correct kind (Swinburne, 2004, pp. 188-191; 206-209). Atheism cannot explain why we live in a universe governed by such laws. Design does explain why our universe is governed by laws which make evolution possible. Looked at this way, the truth of evolution provides confirmation of design. So Swinburne argues:

 Darwin gave a correct explanation for the existence of animals and humans; but not, I think, an ultimate one. The watch may have been made with the help of some blind screwdrivers (or even a blind watchmaking machine). But they were guided by a watchmaker with some very clear sight” (Swinburne, 2010)

It’s important to emphasize that -just as Dawkins is not arguing against evolution or suggesting that scientists should stop working on the origin of life -neither are we. Our purpose is simply to argue that there are reasons to think that it is very unlikely that intelligent life would have come into existence given only unguided natural processes.As Robert Hambourger has argued:

seemingly chance occurrences … did not play a role only in the final stages of the evolution of human beings. It is likely that, at nearly every step in the evolutionary chain that led from the most primitive of creatures to people, similar sorts of occurrences played a role. In fact, without specific evidence one cannot assume even that it was inevitable that mammals, vertebrates, or even multi-celled creatures would evolve. But then, one might ask… whether it could have been simply by chance that so many seemingly unconnected occurrences came together in just the way that would lead to the evolution of creatures capable of reason, and I think that one might well conclude that it could not have been (Hambourger, 1979).

Common Objections

Various objections can be raised. In fact, to some extent the objections parallel those on fine-tuning. One objection is that future science, or perhaps even current science, will undermine this argument by showing that various transitions to more complex forms of life are not so improbable after all. Based on evolutionary convergence, the palaeontologist Simon Conway Morris argues that the existence of intelligent life was almost inevitable once life got started, although he also believes that the origin of life in the first place was very unlikely. In his view “..life has a peculiar propensity to ‘navigate’ to rather precise solutions in response to adaptive challenges’ (Conway Morris, 2003, p. 308).

While he argues that evolutionary processes are much more constrained than many scientists have thought, Conway Morris does not believe that this would undermine theism. He believes that we need a research programme which explores how evolution ‘navigates’ to  particular functional solutions.

“This, of course, begs the question as to how the vastness of a given biological ‘hyperspace’ is actually navigated. This is because the number of potential ‘blind alleys’ is so enormous that in principle all the time since the beginning of the universe would be insufficient to find the one in a trillion-trillion solutions that actually work…The stock response is to invoke a million monkeys typing alternatives, with the invisible hand nudging the myriad of efforts to the correct Shakespearean sonnet (or whatever). This really misses the point, first because it presupposes that the correct solution is known all along, and second because it fails to tackle the problem of the almost illimitable size of biological ‘hyperspaces’. The metaphor of ‘navigation’, however, suggests a more fertile research programme than the mass employment of monkeys. This is because it will attempt to explain, not only the preferred trajectories to the optimum, but also evolution’s uncanny ability to find the short cuts across the the multi-dimensional ‘hyperspace’ of biological reality. It is my suspicion that such a research programme might reveal a deeper fabric to biology in which Darwinian evolution remains central as the agency, but the nodes of occupation are effectively predetermined from the Big Bang. (Conway Morris, 2003, p.309-310)

Dawkins attempts to rescue his argument that evolution explains design away by arguing that there must be billions and billions of Earth-like planets in the universe. Most of these are lifeless; on a small fraction life “evolves”; on a smaller fraction still eukaryotic life evolves; and on a still smaller fraction conscious life evolves. (Dawkins, 2006, pp168-169). Take the origin of life. One any one particular planet, it might be extremely improbable that life would arise from non-living material. However, given the vastness of the universe it is not improbable that it would happen somewhere. Of course, we find ourselves in a place where it has happened. This is what Dawkins seems to mean by ‘anthropically justified’: he assumes that the universe must contain “billions and billions” of Earth-like planets, because this is the only way to account for the existence of beings like humans.

Dawkins makes two crucial assumptions. First, that there are billions and billions of Earth-like planets – that is, planets capable of supporting  conscious animals. It is important to realise that Dawkins does not offer any evidence for the existence of these worlds.Second that planets which bridge “all three gaps” are “intensely rare planets” (Dawkins, 2006, 169). Remember, Dawkins ‘gaps’ are events of very low probability, yet of immense importance in evolutionary history: the origin of life, the origin of eukaryotic cells, and the origin of consciousness.

How big does the universe need to be for this to take place? Is the universe actually that big? Does it contain the right number of planets to make the existence of life probable? What evidence is there for these planets? Put that to one side; let’s suppose that in a few places in the universe life did develop. But then it seems that multicellular life would only develop in a very small fraction of these cases. And the same would be true for each improbable step. It might be that using this strategy, even if life had developed many times elsewhere it would never have got beyond the level of bacteria.

Now, it is not at all clear that the universe is teeming with Earth-like planets, with all the features necessary to support populations of conscious animals (Conway Morris, 2003, pp. 69-106).But not only Dawkins has hypothesised the existence of billions and billions of Earth like planets. Without a shred of evidence, he then goes on to tell us what life is like on these planets! He assumes that only a very small fraction of other Earth like planets could have conscious animals. Unguided evolution does not have the power to produce conscious animals on every Earth like world. But suppose there are billions and billions of Earth like planets. Suppose that these planets were teeming with conscious animals! That would be extraordinarily strong evidence against Dawkins’ explanation of life on Earth and strong evidence for design.

Dawkins originally offered evolution as an hypothesis that  explained the existence of complex life on Earth. It now seems that it can only explain the existence of complex life given billions and billions of Earth-like planets. Dawkins is creating a new hypothesis and assuming the additional evidence exists to confirm it. But our only evidence is the organised complexity and taxonomic diversity of life on Earth: that evidence supports design.

Consciousness Raising Arguments 

Finally, but critically, there are some features of life that a purely physical theory cannot account for. One of the most remarkable features of the living world is the existence of conscious organisms. However, we have very little reason to expect the existence of such organisms if the only forces at work have been physical and unguided.  The problem is (as we have argued in more detail elsewhere) [3] that mental properties (like “pain”, “red” or “melancholy”) are radically different from, and irreducible to, quantifiable physical properties (like “mass” or “charge”). More simply put, there are facts about animals that are not physical facts – facts about “what it is like” to have a particular experience or perspective on the world.

If we describe every physical fact about an organism, we still leave out its conscious state (“what it is like” to be that organism: what it experiences). An “explanatory gap” emerges: physical theories only allow us to predict physical phenomena. Nothing about charge or mass, or any other physical property explains the emergence of mental properties. There is absolutely nothing about a collection of physical parts that explains the emergence of thought; thoughts and atoms are just too dissimilar. This leaves atheistic accounts of life on Earth with a problem: they are not being asked to explain the emergence of complex, non-conscious automata. Rather, they must account for the existence of feeling, thinking creatures. Indeed, consciousness is their most valuable feature; a point that many of Thomas Nagel’s critics overlooked:

What kind of explanation of the development of these organisms, even one that includes evolutionary theory, could account for the appearance of organisms that are not only physically adapted to the environment but also conscious subjects? In brief, I believe it cannot be a purely physical explanation. What has to be explained is not just the lacing of organic life with a tincture of qualia but the coming into existence of subjective individual points of view— a type of existence logically distinct from anything describable by the physical sciences alone. If evolutionary theory is a purely physical theory, then it might in principle provide the framework for a physical explanation of the appearance of behaviorally complex animal organisms with central nervous systems. But subjective consciousness, if it is not reducible to something physical, would not be part of this story; it would be left completely unexplained by physical evolution— even if the physical evolution of such organisms is in fact a causally necessary and sufficient condition for consciousness.

… since the conscious character of these organisms is one of their most important features, the explanation of the coming into existence of such creatures must include an explanation of the appearance of consciousness. That cannot be a separate question. An account of their biological evolution must explain the appearance of conscious organisms as such. Since a purely materialist explanation cannot do this, the materialist version of evolutionary theory cannot be the whole truth. Organisms such as ourselves do not just happen to be conscious; therefore no explanation even of the physical character of those organisms can be adequate which is not also an explanation of their mental character. In other words, materialism is incomplete even as a theory of the physical world, since the physical world includes conscious organisms among its most striking occupants (Nagel, 2012, pp.44-45)

Any account on Earth which only appeals to undirected, physical processes leaves the existence of conscious animals unexplained and inexplicable. Yet, on a religious worldview consciousness isn’t mysterious at all.  The theist believes that there is more to reality than the physical; ultimately a person is at the root of everything else that exists. That person would have good reason to bring about conscious beings; especially a community of intelligent, conscious observers, who could enjoy creation.

In parts 1 and 2 we’ve argued that it would not be at all surprising to find order in a universe created by an intelligent mind since we know from our own experience that intelligent beings are capable of producing order and, as we’ve seen, intelligent life involves very high degrees of order. And we also argued that if the universe is created by God, we would have some reason to expect it to exhibit beauty and other valuable entities which would include intelligent, moral beings. So there are clear reasons for thinking that intelligent life is much more likely in a universe created by God than in a universe involving only unguided natural processes. If that is right, then the existence of intelligent life provides additional evidence for God.


References and Further Reading

Conway Morris, S. (2003)  Life’s Solution: Inevitable Humans in a Lonely Universe (New York: Cambridge)

Dawkins, R. (1986) The Blind Watchmaker (New York: Oxford University Press)

Dawkins, R. (1989) The Selfish Gene (New York: Oxford University Press)

Dawkins, R . (1996) Climbing Mount Improbable ( London: Penguin)

Dawkins, R . (2004) The Ancestor’s Tale ( London: Phoenix)

Dawkins, R. (2006) The God Delusion (London: Bantam Press)

Garvey, B. (2007) Philosophy of Biology (Stocksfield: Acumen)

Glass, D. (2012) “Can evidence for design be explained away?” in Probability in the Philosophy of Religion, edited by Chandler, J. and Harrison, V. (Oxford: Oxford University Press)

Hambourger, R. (1979) “Can design arguments be defended today?” reprinted in Philosophy of Religion: a Guide and Anthology (2000) edited by Davies B. (Oxford: Oxford University Press)

Lane N. “Life: Inevitable or fluke?” New Scientist, 21 June 2012.

Nagel, T (2012) Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False (Oxford: Kindle Edition)

Sober, E. “Contingency or Inevitability? What would happen if the evolutionary tape were replayed? A review of Simon Conway Morris’s Life’s Solution: Inevitable humans in a lonely universe.” New York Times, November 30, 2003.

Sober, E. (2011) “Evolution without Naturalism” in Oxford Studies in the Philosophy of Religion Volume 3, edited by Kvanig, J. (Oxford: Oxford University Press)

Sterelny, K. (2007) Dawkins vs. Gould: Survival of the Fittest (Cambridge: Icon Books)

Swinburne, R. (2004) The Existence of God (Oxford: Oxford University Press)

Swinburne, R. (2008) Is There A God? (Oxford: Oxford University Press)

Ward, K. (1996) God, Chance and Necessity (London: Oneworld Publications)


[1] When it comes to the interpretation of Genesis One, we’re a broad church at Saints and Sceptics. So we are not interested in critiquing Theistic Evolution, Intelligent Design or Creationism. Rather, we are much more interested in pointing out that even if “evolution is true”, a powerful design argument still stands.¹

[2] Perhaps the universe is infinitely large. Well, perhaps, but it’s far from clear that it is. And even if it is it would need to have the right distribution of matter to guarantee that each of the improbable steps would occur.

[3] http://www.saintsandsceptics.org/the-evidence-for-god-consciousness/ http://www.saintsandsceptics.org/swinburne-on-mind-morality-and-meaning/

¹To avoid needless fretting about  Adam and the Fall keep this in mind: Adam fell; because Adam fell, all my ancestors  since Adam were fallen creatures; because all my ancestors since were fallen creatures, I am a fallen creature. That preserves the biblical doctrine of original sin, and is compatible with many scientific scenarios.