Robyn Williams Speaks with Anthony Garrett, formerly of Sydney University,
Ockham's Razor - ABC Radio National Transcripts Sunday, 15 November, 1998
When I lived in Australia and was a member of the committee of the
Australian Skeptics I was an atheist. Since then I have become a Christian. How, then,
have my views changed on the hottest controversy involving science and theology: the
theory of evolution? And make no mistake, it is still the hottest controversy. I am now
involved with answering questions put by e-mail to the
Christians and Christian Students in Science
website in the UK, [this web site is inoperative as of August
and about half the questions are on this topic alone.
My own input to the Skeptics was mainly to expose abuses of established science, and to defend the scientific method that has brought us, for example, cures and preventative methods against a vast range of horrendous diseases that our ancestors lived in fear of. I did not involve myself, thankfully, with the ghostbusting side. I was a physicist and evolutionary biology was not my field, but the theory of evolution made good sense to me and I automatically assumed that it ran counter to the account of creation given at the start of the Bible in the book of Genesis. Since I was not a Christian, this was not a problem for me.
I did not become a Christian because of logical argumentation. Conversion is always more personal than that. But afterwards I was faced with the problem of the differing accounts of life according to Genesis and Darwin. Initially I put the problem on hold, since I was exploring other aspects of my new belief which were more important to me. When I came back to it, it seemed obvious that the best thing to do was to look at what those Christians who were also well informed about biology believed. This was a good idea because you want to learn about your own religion from others who share it, and because the theory of evolution is a technical theory which demands considerable expertise to discuss properly. Because biology is not a mathematical science it can be discussed by anybody, and its majesty and complexity have been under-rated. And certainly there are plenty of scientists who are Christians to ask: a survey in the leading scientific journal Nature, in April 1997, showed belief in a personal God among scientists close to 40percent, almost exactly the same as in 1916.
Here is the surprise: almost all the Christians who actually understand the theory of evolution find that there is no clash between the Biblical account and the account due to natural selection. The clash is made up of atheists on one side, and Christians who hold a particular interpretation of the Biblical account on the other. But it is not the only interpretation, and it is not one that all Christians share. In retrospect it is not surprising that reconciliation is possible, since science itself grew out of a Christianised culture. I shall argue that the polarisation in the debate, which is now in its second century and runs with an intensity that is painful to all, corresponds to a mistaken false polarisation between faith and reason that extends back many centuries.
Darwinists, both secular and Christian, believe that man has evolved by a continuous chain of reproduction, over millions of years, from far simpler creatures. On the other side are the creation scientists, Christians who have faith that the account of the creation of the world and of man given in the book of Genesis is - quote - "literally true"; since this account cannot be reconciled with that of evolution, they maintain in all sincerity that evolution is false.
There are two ways in the Bible of explaining what is happening. One
says that God makes something happen. The other describes events in terms of earthly cause
and effect: David slew Goliath by using a primitive catapult to project a stone at him.
But it was still part of God's plan, and since he is in charge of everything, he is also
responsible for it. To Christians these two types of explanation are not opposed, but
complementary. They are both true at once.
When it comes to evolution, though, the two categories of explanation are held by some to be not complementary but opposed. The God-did-it account of the creation of humans given in Genesis, and the account of human creation using descriptive tools like logic that are themselves part of creation, are seen as opposed. This is due to a misunderstanding about purpose. Because evolution gives a cause-and-effect account of human origins, it says nothing about the purpose of its subject. It is exclusively about how, not why; the Whys are in the Bible. At this point we can see what causes the trouble: because evolution gives an account of human descent that is silent about purpose, people like Richard Dawkins suppose it asserts that there is no such purpose. This is a logical error. Evolution, being silent about purpose, cannot be taken to imply either that there is or is not purpose to human existence. To support or attack the theory on the grounds that it implies there is no purpose to human life, as some atheists and some Christians respectively do, is to commit this error.
In a wider perspective, it has been the whole drive of the Enlightenment movement that began in the 18th century to extend the successes of the new, purpose-free, cause-and-effect descriptions of matter that is science into the human realm. This effort can be very valuable; however the Enlightened typically suppose that their purpose-free description is the only one there can be. The atheists who are attracted to evolution are therefore in the main stream of the last two hundred years of thought. Unfortunately, Western Christianity was in no position to correct the error. By accepting the false supposition that faith and reason were opposed and not complementary, it had unwittingly prepared the ground for the Enlightenment. Therefore as reason advanced, the Christian faith declined. When it finally stood and fought, over the issue of evolution in which the perceived crisis of purpose was most acute, it had lost the ability to point out that the twin descriptions of an event, God's-eye (by faith) and man's-eye (using reason), were complementary, not opposed. Darwin himself believed that his theory posed a problem for the church, to which he was well disposed at that stage of his life, and he agonised over its publication. But this is the confusion that led ultimately to a prostitute being dressed up as the goddess of reason and enthroned on the altar of Paris's principal church at the height of the French revolution. For faith and reason are not opposed - for a start, you have to have faith in reason, and secondly reasoning enables you to demonstrate one thing from another. But where does that original thing come from? Your starting position is, unavoidably, held by faith.
That is the wider context of the dispute. But to return to the specific, how can the Genesis account be reconciled with evolution's account? The answer lies in the creation scientists' claim that the Bible is "literally true". Now this is a tautology; it means exactly the same as just "true". But it unwittingly hides what is meant, that the Bible is materially or physically true; and this claim involves interpretation of the Scriptures. So it is really a debate about the interpretation of scripture - a theological debate. It is an assumption of the scientific, material-dominated culture in which the creation scientists live that material truth is the highest truth, but since there are other forms of truth this is not necessarily so. In the four Gospels there are materially irreconcilable accounts of where Jesus was, what he did and said, during certain events. Taken as material fact in the way the creation scientists claim, the Bible therefore contradicts itself. But taken as stories - fables or parables - used to make theological points, there is no problem.
So, a purpose-free, cause-and-effect description of human descent is worth seeking, and need not be opposed to the Biblical account. Evolution provides such an account; but is it the correct one? This is a purely scientific issue. Having, I hope, taken the excess heat out of the debate, I will run through evolution including the evidence for it and the usual tricky questions.
The basic idea is that there is a wide variation in physical and behavioural characteristics among individuals of a distinct species. This diversity - in height, build and skin colour in humans, for example - reflects a diversity in the gene pool of a species. Genes are chemically encoded instructions, inherited from parents, for particular characteristics. What counts is that some individuals will be better adapted to survive in a particular environment; for example, moths whose wing colour more closely matches the bark of local trees are more likely to escape being eaten by birds and pass on their own colour-coded genes. This is "natural selection". The species responds to the environment and to changes in it. Differences can be brought out by so small an incident as one group wandering off from another into a different environment; this has led to differing human skin colours, for example. Separation, followed by differing changes of environment, can lead over time to differences so great that, by accepted criteria such as appearance and inability to interbreed, different species are created.
Natural selection clearly acts to reduce the diversity of the gene pool. The opposing effect, tending to increase genetic diversity, is mutation - changes at the genetic level due to miscopying as cells divide, or other local chemical mechanisms, that then express themselves as new characteristics. We see only the viable mutations - most mutant cells die immediately upon their creation.
Two common objections put up by creationists and other anti-evolutionists are the paucity of intermediate types in the fossil record; and how (for example) a bird's wing could have evolved, given that a half-sized intermediate organ would be useless for flying. Both can be answered. Certainly there are some missing links between species in the fossil record. Their low number can be explained if the process of differentiation into distinct species takes place on timescales short compared to the typical lifetime of a species, so that evolution proceeds in short bursts and intermediate forms would only be available to go into the fossil record for a relatively short time. This idea is called "punctuated equilibrium" and is looking ever better as we begin to learn by computer modelling how new mutations can lead to bifurcation of species in only a few generations; also in its support are recent realisations that most of the history of the Earth has been dominated by sudden violent environmental changes rather than gradual ones - and it is environmental change that drives evolution.
As to intermediate organs such as half a wing, the objection implicitly assumes that the appendage would be used only for flying. But, when it first began to evolve, it may have had some other function for which it proffered immediate advantage; when large enough it could then have continued evolving specifically for flying. For example, flamingos use their wings not only to fly but also to shield the water surface from the sun's glare when they are hunting for fish; even a small appendage helps here. Intermediate organs can have intermediate functions, and functions, unlike structures, cannot immediately be inferred from the historical record.
Here, now, is the evidence that man is descended by a continuous chain of reproduction from simpler organisms. First, the fossil record shows an ever-increasing complexity of organisms as time goes on, including some intermediate forms, and most recently bipedal, man-like creatures. Then there are similarities between species, suggesting common ancestry. For example the forelimb - the upper arm, forearm, wrist, hand and fingers - can be matched bone for bone in creatures as diverse as the horse, porpoise, bat, rat, mole and man. Given the widely differing uses of the forelimb across these species it is implausible to argue that similar functions have necessitated such close similarities. Next is the existence of organs such as the appendix, without which humans survive perfectly well, but vital in animals of close structure to man's. What else could this imply than a common ancestor followed by a divergence?
More evidence for common ancestry comes from embryology: the embryos of lizards, birds and mammals are at stages indistinguishable from each other, showing a similarity in those genes expressed at this early stage of an individual's life - a stage where there is no selection pressure, so that if they were unrelated they might well have been different. There are also similarities in behaviour of distinct species: thrushes in South America and Britain line their nests with mud in similar ways. It is hard to credit that there is an advantage in one technique of mud lining over another, so common ancestry is again suggested. More evidence comes in the geographic distribution of animals as land masses connect and isolate themselves. The fossil record is consistent, as it need not have been otherwise, with natural selection acting on isolated populations having
Finally, there is molecular evidence for evolution. For example, insulin has the same function in differing animal species (including man) but slightly different amino acid structure. A "family tree" can be reconstructed based on these divergences. As best we can tell it agrees with the family tree reconstructed from the record. Above all, this is true for the order of genes themselves in the DNA molecule - which is the medium of transmission of inherited characteristics. Moreover the DNA of man is very close, link by link, to that of even very simple creatures; and the similarity grows as the complexity of the creature grows, mirroring the fossil record.
Evolution explains all these facts through a single principle. Rejecting it, they become merely an unrelated collection of observations. The real question for scientists is whether the neo-Darwinian synthesis of natural selection and genetics can explain every biological structure and the great diversity found in nature, so that it is a question of filling in the great gaps in the picture, or whether further unknown principles are involved.
Now I have said what Darwinism is, I want to spend a few moments saying what it isn't. The theory is often held to support a view that is unfortunately known as Social Darwinism but might better be called antisocial Darwinism: in human societies, let all compete and let the weak go to the wall. Leaving the weak to die is against the message of the Bible and just about every other great religion. Social Darwinism is not only obnoxious, it has nothing to do with actual Darwinism. If we are genetically programmed exclusively to compete against each other, why is there so much cooperation among humans in all societies? Moreover, the fact of competition or cooperation is a long way from being proven to be genetic: much of it may be learned. After all, societies which are genetically similar may have different attitudes to competition and cooperation. Not only is Social Darwinism morally objectionable, it is scientifically unsupported. And to extrapolate this argument from individuals to races, as Hitler tried, is yet another unjustified step, and an evil one.
In conclusion I want to return to the Genesis/Darwin debate, and I call on atheists who think that the Genesis account is simply outdated to accept that evolutionary theory says nothing about purpose either way. I also call on creation scientists to recognise the untenability of an exclusively material interpretation of Scripture and to accept that the Genesis account and evolution's account may be complementary, just as God's hand may be seen in events we give routine cause-and-effect explanations to. Let us keep our eyes on the question of what would be seen as we trace the ancestors of an animal or a person back through successive generations, and how it might be explained.
I further call on all sides to recognise that this is primarily a theological debate. Theology is more fundamental than science; good theology has led to good science, in the emergence of Darwinism from the mainstream of a Christian civilisation, and bad theology has led to bad science, in the creation scientists' material interpretation of Genesis and their consequent torturing of the scientific facts to construct crazy scientific theories like the 6000-year-old Earth, that they believe in genuine sincerity. Seeing that the issue lies not inside science but beyond it might foster the mutual understanding that leads to reconciliation.
Anthony Garrett, PhD
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