From summer 1998 - Evolution - a Theory in Crisis?
Microevolution refers to evolution at and below the species level, as exemplified in Kettlewell's famous studies of the variation in the proportion of light to dark coloured moths in a population of peppered moths, or by Weiner's study of finch beak lengths. This aspect of the theory is really not controversial. Indeed, many of the examples given are scarcely evolution at all, if that term carries a sense of permanent direction change. They are rather examples of cyclical variation within fundamentally stable species.
Macroevolution is the evolution of the living cell from non-living materials, of multicellular from single-celled structures, of new body plans, new organs etc... Usually macroevolution is associated closely with the idea of descent with modification, often illustrated by phylogenetic trees tracing the chronological descent of living things from common ancestors. This theory is more controversial. Those who believe it can be roughly divided into two groups. There are those who believe that there is a God who has used these methods under his supervision to produce life in all its variety. Among those who hold this theistic-evolutionary view are distinguished scientists such as Sir Ghillean Prance and Professor Sam Berry. A larger group, represented most vocally by Professor Richard Dawkins, subscribe to the 'Blind Watchmaker' thesis (Johnson's helpful term based on Dawkins), the belief that the processes driving evolution are blind and undirected.This article is concerned more with the latter group although it will be obvious that there are significant points of contact with the former.
Dawkins uses biology as a vehicle to convey the impression that atheism is the only rationally defensible intellectual position. He claims that 'although atheism might have been logically tenable before Darwin, Darwin made it possible to be an intellectually fulfilled atheist'.
Dawkins stands in a lengthy tradition. Sir Julian Huxley, at the Darwin Centennial, University of Chicago, in 1959 said: 'In the evolutionary pattern of thought there is no longer either need or room for the supernatural.' In the same vein, Nobel laureate Jacques Monod writes: 'Pure chance, absolutely free but blind, is at the very root of the stupendous edifice of evolution with the result that man at last knows that he is alone in the unfeeling immensity of the universe... Neither his destiny nor his duty have been written down.' Thus, Monod not only banishes God from the universe, he denies any concept of absolute morality.
Dawkins has no doubt that with Darwin we reach a historical watershed:
'We no longer have to resort to superstition when faced with deep problems: Is there a meaning to life? What are we for? What is man? When you are actually challenged to think of pre-Darwinian answers to the questions, can you, as a matter of fact, think of any that are not now worthless except for their (considerable) historical interest? There is such a thing as being just plain wrong, and that is what, before 1859, all answers to these questions were.'[8,9]
It is therefore scarcely surprising that there is a widespread feeling that the theory of evolution has swept God away as unnecessary and irrelevant, if not positively embarrassing, to the twentieth century mind. The eminent philosopher Roger Scruton who, on being asked why he did not believe in God, replied: 'I have a scientific mind; I can't just dismiss the evidence of Darwinism: it seems to me to be obviously true.'
However, even if we grant, for the sake of argument, that through evolutionary theory the biological workings of the universe can be explained, that no more does away with the need to posit a Creator than explaining how a Ford car works does away with the need to believe in Henry Ford. As Poole points out: 'There is no logical conflict between reason-giving explanations which concern mechanisms, and reason-giving explanations which concern the plans and purposes of an agent, human or divine. This is a logical point, not a matter of whether one does or does not happen to believe in God oneself.'
Deducing atheism from biology is therefore a very suspect philosophical procedure in itself. However, in some prominent cases, far from the philosophy being deduced from the science, the very reverse is true. Richard Lewontin, a world famous geneticist at Harvard, writes:
'Our willingness to accept scientific claims that are against common sense is the key to an understanding of the real struggle between science and the supernatural. We take the side of science in spite of the patent absurdity of some of its constructs... in spite of the tolerance of the scientific community for unsubstantiated just-so stories, because we have a prior commitment...to materialism. It is not that the methods and institutions of science somehow compel us to accept a material explanation of the phenomenal world but, on the contrary, that we are forced by our a priori adherence to material causes to create an apparatus of investigation and a set of concepts that produce material explanations, no matter how counterintuitive, no matter how mystifying to the uninitiated. Moreover that materialism is absolute for we cannot allow a divine foot in the door.' This revealing statement from a prominent member of the scientific establishment is a far cry from the common naive understanding of science as impartially following the implications of experiments wherever they lead. For Lewontin, commitment to materialism comes first, the science follows. And if you shape your science in such a way that you are never in danger of detecting a divine footprint, then of course you never will. But that is to leave wide open the question as to whether divine footprints exist!
What is more, if there is no Creator, then something like Darwinism must hold as a matter of elementary deduction, quite apart from the evidence. Matter must have the capacity to organise itself into all the biodiversity we see. There is no other possibility. Putting it in the logically equivalent negative way makes the issue at stake even clearer: if matter does not possess this capacity, then materialism is false and Huxley, Monod and Dawkins' thesis collapses. They, therefore, have an enormous vested interest in the validity of evolutionary theory.
This is a risky question to ask, since in the eyes of many it is to question sheer fact and reopen a debate long since closed! Richard Lewontin writes: 'It is time...to state clearly that evolution is fact, not theory...Birds arose from nonbirds and humans from nonhumans. No person who pretends to any understanding of the natural world can deny these facts any more than she or he can deny that the earth is round, rotates on its axis and revolves around the sun'.
Dawkins, as ever, is not to be outdone: 'It is absolutely safe to say that if you meet somebody who claims not to believe in evolution that person is ignorant, stupid or insane (or wicked, but I'd rather not consider that)'.
So, to question evolution is to leave yourself open to the accusation of scientific naiveté. Now if by 'evolution' you mean microevolution, such an accusation would be understandable. But what about macroevolution? Is it in the same category? Apparently not. For example, Wesson says: 'Large evolutionary innovations are not well understood. None has ever been observed, and we have no idea whether any may be in progress. There is no good fossil record of any'. By contrast, the fact that the earth orbits the sun may be repeatedly observed, there are very good records of it. To put this phenomenon in the same category as macroevolution is such an elementary blunder that one cannot help wondering if fear of a divine footprint is playing a role and that materialistic prejudice is beginning to override common sense.
We must therefore risk a Dawkins' certificate of lunacy and ask whether it is true that, given enough time, simple organisms slowly turn into more complex organisms through the natural processes of mutation and natural selection.
Since no-one is an expert on all aspects of the issue, the first obvious approach to such a question would be to ask whether any of the leaders in the various disciplines are expressing serious misgivings about it.
Darwin himself was concerned about the absence of the transitional forms in the fossil record which his theory led him to expect:
'The number of intermediate varieties, which have formerly existed on the earth, [should] be truly enormous. Why then is not every geological formation and every stratum full of such intermediate links? Geology assuredly does not reveal any such graduated organic chain; and this, perhaps is the most obvious and gravest objection which can be urged against my theory.'
The situation over a hundred years later does not seem very different. Stephen Jay Gould (a palaeontologist from Harvard) said: 'The extreme rarity of transitional forms in the fossil record persists as the trade secret of palaeontology'. His fellow palaeontologist Niles Eldredge of the American Museum of Natural History adds: 'We palaeontologists have said that the history of life supports [the story of gradual adaptive change] knowing all the while it does not'. Eldredge goes on to say: 'When we do see the introduction of evolutionary novelty, it usually shows up with a bang, and often with no firm evidence that the fossils did not evolve elsewhere! Evolution cannot forever be going on somewhere else. Yet that's how the fossil record has struck many a forlorn palaeontologist looking to learn something about evolution'.
In his best selling book Wonderful Life, Gould describes how all the major phyla we have today (plus a good many more which have gone extinct) appeared very suddenly in the so-called 'Cambrian explosion'. Dawkins comments: 'It is as though the fossils were planted there without any evolutionary history'.
Of course, in this very short section I have only selected critical observations. My point is that some leading experts are publicly expressing far-reaching concerns about foundational aspects of the theory.
Microevolution is clearly a necessary condition for macroevolution. But is it a sufficient condition? Is macroevolution simply an extrapolation of microevolution so that in the end there is no distinction between the two? Again, there is disagreement among leading scientists. The verdict of Richard Goldschmidt (geneticist) that 'the facts of microevolution do not suffice for an understanding of macroevolution' still seems to command support. Roger Lewin says: 'The most obvious message is that a simple extrapolation from one level to another is an unlikely explanation of evolutionary innovation at the different levels'. More recently, Gibbert, Opitz and Raff wrote: 'Microevolution looks at adaptations that concern only the survival of the fittest, not the arrival of the fittest'.
These observations are supported by experiments in artificial selection which show that there appear to be limits to the amount of variation even the most skilled breeders can achieve. Pierre Grassé (eminent biologist who was President of the Académie Francaise) points out that fruit flies remain fruit flies in spite of the thousands of generations which have been bred and all the mutations which have been induced. It would appear that the capacity for variation in the gene pool runs out quite early on. Mayr calls this 'genetic homeostasis' - the barrier beyond which selective breeding will not pass because of the onset of sterility or exhaustion of genetic variability.
This is not, however, to say that no element of speciation is to be observed as the result of either natural or artificial selection. The point at issue is whether microevolution is capable of producing essentially new levels of complexity. It would seem that the mechanisms which give rise to variations in moth populations or in the lengths of finch beaks tell us little about how moths or finches came to exist in the first place.
The nucleus of each of the ten trillion cells in the human body contains an incredibly compact database packed full of digital information which would fill more than all 30 volumes of the Encyclopaedia Britannica.
The improbability of even producing complex molecules by random methods is well known. Dawkins cites the example used by Isaac Asimov of the haemoglobin molecule and shows that the chance of hitting on haemoglobin by randomly combining amino-acids is unimaginably small (one in 10^190). It is this kind of calculation that led Sir Fred Hoyle to say: 'The 'probability of life originating by chance is about the same as the probability that a typhoon blowing through a junkyard could produce a Boeing 747!'
So how can the origin of such complexity be explained? Dawkins attempts to solve the difficulty by arguing that, although mutations are random, natural selection is not. In order to illustrate this he goes back to the well known typing monkeys and considers the phrase 'Methinks it is like a weasel'. The probability of getting it right by random typing is extremely small.
But now Dawkins introduces a new feature. Each letter a monkey types is compared with the target phrase (by computer, or by a Head Monkey as mathematician David Berlinski delightfully suggests) and any letters which are in the right positions are retained. The target phrase is then reached very rapidly. Berlinski comments:
'The entire exercise is, however, an achievement in self-deception. A target phrase? Iterations which resemble the target? A computer or head monkey that measures the distance between failure and success? If things are sightless how is the target represented, and how is the distance between randomly generated phrases and the targets assessed? And by whom? And the head monkey? What of him? The mechanism of deliberate design, purged by Darwinian theory on the level of the organism, has reappeared in the description of natural selection itself, a vivid example of what Freud meant by the return of the repressed'.
As has also been pointed out, the phrase might as well have been written out from memory for that is almost what is happening (with a little randomness factored in).
Oddly, Dawkins admits that his analogy is misleading precisely because cumulative natural selection is 'blind to a goal'. He claims that the program can be modified to take care of this point - a claim that is not substantiated anywhere. Indeed, even if his claim were true, it would illustrate the exact opposite of what he believes, since modifying a program is applying yet more intelligence to an already intelligently designed artefact!
At the beginning of 'The Blind Watchmaker' Dawkins says: 'Biology is the study of complicated things that give the appearance of being designed for a purpose' and then spends the rest of the book trying to prove that this appearance is deceptive. It is ironic that his key explanatory argument invokes designed mechanism and undermines his case. Francis Crick's opinion is more realistic: 'The origin of life seems almost to be a miracle, so many are the difficulties of its occurring'.
We now turn to a challenge issued by Darwin himself: 'If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down'. So also would the Blind Watchmaker thesis, according to Dawkins, who says that if such an organ exists 'I shall cease to believe in Darwinism'. Behe, a biochemist, takes up Darwin's challenge. He studies molecular machines, like the mechanism involved in blood-clotting, and argues that not only is the biochemistry very complex but that there exist 'irreducibly complex' systems, which resemble a mouse trap in that they are 'composed of several well-matched interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system effectively to cease functioning'. Take away one part of the blood clotting mechanism and the result may be fatal! Behe argues that there can be no Darwinian explanation for an irreducibly complex system, since any preceding stage in its evolution would have been non-functional and therefore eliminated by natural selection. Behe concludes that such biochemical systems 'seem to be designed for a purpose' because they were designed for a purpose. His work has stirred up considerable controversy and it will be interesting to see what sort of counter arguments appear.
Once we admit the possibility of the causal activity of an intelligent agent, certain familiar things may be seen in a very different light. For example, in many textbooks we see arrangements of similar bone structures from different animals or learn that amphibians, birds and mammals share a number of similar genes. This is usually interpreted as evidence of common ancestry but it could equally well be read as evidence of common design. All cars have similar parts because those parts are essential for their operation; it is because they are constructed according to a common design, not because they have descended from each other.
I am aware that the introduction of the concept of design may provoke charges of defeatism, anti-scientific intellectual laziness and of introducing a 'God of the gaps' to solve problems which might well be overcome in time by further scientific work. However, such charges are not always fair. Meyer's contribution to JP Moreland is an important analysis of the hypotheses of design and descent, showing that the two are methodologically equivalent in the sense that they prove to be equally scientific or equally unscientific depending on the criteria used to assess their scientific status. Furthermore, Dembski argues that intelligent design can be formulated as a scientific theory of information, one far-reaching consequence of which is that complex specified information of the kind encountered in genetic material cannot be generated by natural processes. Thus, far from inhibiting research, a scientific analysis of the concept of design may well lead to real scientific advance.
One of the aims of the scientific endeavour is to infer to the best possible explanation. If one presupposes a naturalistic methodology then evolution is arguably the best explanation for biological complexity. However, this is far from obviously the case if the live options are widened to include theism.
According to the Bible, God is both Designer-Creator and Sustainer of the universe. He is not the God of the gaps whose only traces are to be found in the scientifically inexplicable. His everlasting power and Godhead are clearly seen in all the created order. The more science reveals the more should our wonder grow. Nor is God the God of the Deists, who retires from the universe after creating it and lets it run on its own. Without his upholding power it would cease to exist. Thus God can be said to send the rain and cause the sun to shine.
However, the sequence of creative acts followed by God's sabbath rest, recorded in Genesis 1, alerts us to the fact that God's creation of the universe and life is not the same as his subsequent providential upholding and maintenance of it. This implies that there will be a difference between 'operation' science and 'origin' science. Modern physics recognises this, in that backward extrapolation from laws governing the operation of the universe leads to the concept of a singularity at the beginning.
The distinction between origin and operation at the level of human beings is underlined by Paul in Acts 17.26 which says of God: 'From one man he made every nation of men...'. Hence, the creation of the first man is not the same as the subsequent making of all nations from him. It is instructive to consider what the latter involves.
We could call this the micro-perspective of Scripture. There is also a macro-perspective. When it comes to creation, as has often been pointed out, surprisingly little is said about mechanism - how it was done. However, what is said is of utmost significance. The repeated 'And God said...' in Genesis 1 is summed up in the 'In the beginning was the Word... all things were made by Him' of John 1 and the 'By faith we understand that the universe was made at God's command' in Hebrews 11:3. 'Said', 'Word', 'Command' - this is the terminology of the communication of information. This is remarkable. Here is the Bible, which so many have dismissed as primitive, identifying the origin of information as the key issue in creation, a fact which has only been relatively recently recognised by science. What is more, however we understand the days of Genesis (a subject in its own right), they do seem to indicate at least that God did not create everything at once. The repeated 'and God said' would indicate a sequence of inputs of information and creative energy, entailing the logical consequence that an additional input of information was necessary to get from stage n to stage n+1. Hence, if you try to explain stage n+1 in terms of, say, the physics and chemistry operating at stage n, you will inevitably fail. To put it another way, microevolution operating at stage n might well lead to a lot of variation but would never produce stage n+1.
In light of this, what might we expect to find if we study nature through the lens of a theory that holds that the complete history of life from the pre-biotic to man is one seamless developmental whole? Surely, what Dawkins, although he is unaware of it, has found that the theory will not work without smuggling a designing intelligence in by the back door, as exemplified by his monkey story. Purely mechanistic explanations are both in principle and in fact inadequate. Thus Scripture seems to bear out what science has discovered.
God of the gaps? No, at least not in the usual pejorative sense of a God who disappears as each new mechanism is discovered. Think of the page you are reading. The chemistry of the paper and ink can not even in principle help you to comprehend the semiotics of the words written in the ink. That the shape of the letters is designed is, if you like, a 'gap' in the explanatory power of chemistry. But if we enlarge our universe to include the intelligence of an author then there is a higher level explanation which includes both his designing activity and chemistry.
The events central to Christianity - that God, the Word, 'encoded' himself in humanity and became flesh and that Jesus rose from the dead - clearly did not occur as a result of the normal outworking of the laws of nature which had been operating up to that time. Those events involved totally new inputs of information and colossal energy. What I am arguing is that the Bible indicates that a similar thing is true of creation - that God created in stages by feeding in the necessary information and energy. In consequence, any scientific theory which does not allow for such inputs will experience an inevitable crisis as an inadequate paradigm.