Richard Dawkins Essays About Life
America, founded in secularism as a beacon of eighteenth century enlightenment, is becoming the victim of religious politics, a circumstance that would have horrified the Founding Fathers. The political ascendancy today values embryonic cells over adult people. It obsesses about gay marriage, ahead of genuinely important issues that actually make a difference to the world. It gains crucial electoral support from a religious constituency whose grip on reality is so tenuous that they expect to be 'raptured' up to heaven, leaving their clothes as empty as their minds. More extreme specimens actually long for a world war, which they identify as the 'Armageddon' that is to presage the Second Coming. Sam Harris, in his new short book, Letter to a Christian Nation, hits the bull's-eye as usual:
It is, therefore, not an exaggeration to say that if the city of New York were suddenly replaced by a ball of fire, some significant percentage of the American population would see a silver-lining in the subsequent mushroom cloud, as it would suggest to them that the best thing that is ever going to happen was about to happen: the return of Christ . . .Imagine the consequences if any significant component of the U.S. government actually believed that the world was about to end and that its ending would be glorious. The fact that nearly half of the American population apparently believes this, purely on the basis of religious dogma, should be considered a moral and ¬intellectual emergency.
Does Bush check the Rapture Index daily, as Reagan did his stars? We don't know, but would anyone be surprised?
My scientific colleagues have additional reasons to declare emergency. Ignorant and absolutist attacks on stem cell research are just the tip of an iceberg. What we have here is nothing less than a global assault on rationality, and the Enlightenment values that inspired the founding of this first and greatest of secular republics. Science education - and hence the whole future of science in this country - is under threat. Temporarily beaten back in a Pennsylvania court, the 'breathtaking inanity' (Judge John Jones's immortal phrase) of 'intelligent design' continually flares up in local bush-fires. Dowsing them is a time-consuming but important responsibility, and scientists are finally being jolted out of their complacency. For years they quietly got on with their science, lamentably underestimating the creationists who, being neither competent nor interested in science, attended to the serious political business of subverting local school boards. Scientists, and intellectuals generally, are now waking up to the threat from the American Taliban.
Scientists divide into two schools of thought over the best tactics with which to face the threat. The Neville Chamberlain 'appeasement' school focuses on the battle for evolution. Consequently, its members identify fundamentalism as the enemy, and they bend over backwards to appease 'moderate' or 'sensible' religion (not a difficult task, for bishops and theologians despise fundamentalists as much as scientists do). Scientists of the Winston Churchill school, by contrast, see the fight for evolution as only one battle in a larger war: a looming war between supernaturalism on the one side and rationality on the other. For them, bishops and theologians belong with creationists in the supernatural camp, and are not to be appeased.
The Chamberlain school accuses Churchillians of rocking the boat to the point of muddying the waters. The philosopher of science Michael Ruse wrote:
We who love science must realize that the enemy of our enemies is our friend. Too often evolutionists spend time insulting would-be allies. This is especially true of secular evolutionists. Atheists spend more time running down sympathetic Christians than they do countering ¬creationists. When John Paul II wrote a letter endorsing Darwinism, Richard Dawkins's response was simply that the pope was a hypocrite, that he could not be genuine about science and that Dawkins himself simply preferred an honest fundamentalist.
A recent article in the New York Times by Cornelia Dean quotes the astronomer Owen Gingerich as saying that, by simultaneously advocating evolution and atheism, 'Dr Dawkins "probably single-handedly makes more converts to intelligent design than any of the leading intelligent design theorists".' This is not the first, not the second, not even the third time this plonkingly witless point has been made (and more than one reply has aptly cited Uncle Remus: "Oh please please Brer Fox, don't throw me in that awful briar patch").
Chamberlainites are apt to quote the late Stephen Jay Gould's 'NOMA' - 'non-overlapping magisteria'. Gould claimed that science and true religion never come into conflict because they exist in completely separate dimensions of discourse:
To say it for all my colleagues and for the umpteenth millionth time (from college bull sessions to learned treatises): science simply cannot (by its legitimate methods) adjudicate the issue of God's possible superintendence of nature. We neither affirm nor deny it; we simply can't comment on it as scientists.
This sounds terrific, right up until you give it a moment's thought. You then realize that the presence of a creative deity in the universe is clearly a scientific hypothesis. Indeed, it is hard to imagine a more momentous hypothesis in all of science. A universe with a god would be a completely different kind of universe from one without, and it would be a scientific difference. God could clinch the matter in his favour at any moment by staging a spectacular demonstration of his powers, one that would satisfy the exacting standards of science. Even the infamous Templeton Foundation recognized that God is a scientific hypothesis - by funding double-blind trials to test whether remote prayer would speed the recovery of heart patients. It didn't, of course, although a control group who knew they had been prayed for tended to get worse (how about a class action suit against the Templeton Foundation?) Despite such well-financed efforts, no evidence for God's existence has yet appeared.
To see the disingenuous hypocrisy of religious people who embrace NOMA, imagine that forensic archeologists, by some unlikely set of circumstances, discovered DNA evidence demonstrating that Jesus was born of a virgin mother and had no father. If NOMA enthusiasts were sincere, they should dismiss the archeologists' DNA out of hand: "Irrelevant. Scientific evidence has no bearing on theological questions. Wrong magisterium." Does anyone seriously imagine that they would say anything remotely like that? You can bet your boots that not just the fundamentalists but every professor of theology and every bishop in the land would trumpet the archeological evidence to the skies.
Either Jesus had a father or he didn't. The question is a scientific one, and scientific evidence, if any were available, would be used to settle it. The same is true of any miracle - and the deliberate and intentional creation of the universe would have to have been the mother and father of all miracles. Either it happened or it didn't. It is a fact, one way or the other, and in our state of uncertainty we can put a probability on it - an estimate that may change as more information comes in. Humanity's best estimate of the probability of divine creation dropped steeply in 1859 when The Origin of Species was published, and it has declined steadily during the subsequent decades, as evolution consolidated itself from plausible theory in the nineteenth century to established fact today.
The Chamberlain tactic of snuggling up to 'sensible' religion, in order to present a united front against ('intelligent design') creationists, is fine if your central concern is the battle for evolution. That is a valid central concern, and I salute those who press it, such as Eugenie Scott in Evolution versus Creationism. But if you are concerned with the stupendous scientific question of whether the universe was created by a supernatural intelligence or not, the lines are drawn completely differently. On this larger issue, fundamentalists are united with 'moderate' religion on one side, and I find myself on the other.
Of course, this all presupposes that the God we are talking about is a personal intelligence such as Yahweh, Allah, Baal, Wotan, Zeus or Lord Krishna. If, by 'God', you mean love, nature, goodness, the universe, the laws of physics, the spirit of humanity, or Planck's constant, none of the above applies. An American student asked her professor whether he had a view about me. 'Sure,' he replied. 'He's positive science is incompatible with religion, but he waxes ecstatic about nature and the universe. To me, that is ¬religion!' Well, if that's what you choose to mean by religion, fine, that makes me a religious man. But if your God is a being who designs universes, listens to prayers, forgives sins, wreaks miracles, reads your thoughts, cares about your welfare and raises you from the dead, you are unlikely to be satisfied. As the distinguished American physicist Steven Weinberg said, "If you want to say that 'God is energy,' then you can find God in a lump of coal." But don't expect congregations to flock to your church.
When Einstein said 'Did God have a choice in creating the Universe?' he meant 'Could the universe have begun in more than one way?' 'God does not play dice' was Einstein's poetic way of doubting Heisenberg's indeterminacy principle. Einstein was famously irritated when theists misunderstood him to mean a personal God. But what did he expect? The hunger to misunderstand should have been palpable to him. 'Religious' physicists usually turn out to be so only in the Einsteinian sense: they are atheists of a poetic disposition. So am I. But, given the widespread yearning for that great misunderstanding, deliberately to confuse Einsteinian pantheism with supernatural religion is an act of intellectual high treason.
Accepting, then, that the God Hypothesis is a proper scientific hypothesis whose truth or falsehood is hidden from us only by lack of evidence, what should be our best estimate of the probability that God exists, given the evidence now available? Pretty low I think, and here's why.
First, most of the traditional arguments for God's existence, from Aquinas on, are easily demolished. Several of them, such as the First Cause argument, work by setting up an infinite regress which God is wheeled out to terminate. But we are never told why God is magically able to terminate regresses while needing no explanation himself. To be sure, we do need some kind of explanation for the origin of all things. Physicists and cosmologists are hard at work on the problem. But whatever the answer - a random quantum fluctuation or a Hawking/Penrose singularity or whatever we end up calling it - it will be simple. Complex, statistically improbable things, by definition, don't just happen; they demand an explanation in their own right. They are impotent to terminate regresses, in a way that simple things are not. The first cause cannot have been an intelligence - let alone an intelligence that answers prayers and enjoys being worshipped. Intelligent, creative, complex, statistically improbable things come late into the universe, as the product of evolution or some other process of gradual escalation from simple beginnings. They come late into the universe and therefore cannot be responsible for designing it.
Another of Aquinas' efforts, the Argument from Degree, is worth spelling out, for it epitomises the characteristic flabbiness of theological reasoning. We notice degrees of, say, goodness or temperature, and we measure them, Aquinas said, by reference to a maximum:
Now the maximum in any genus is the cause of all in that genus, as fire, which is the maximum of heat, is the cause of all hot things . . . Therefore, there must also be something which is to all beings the cause of their being, goodness, and every other perfection; and this we call God.
That's an argument? You might as well say that people vary in smelliness but we can make the judgment only by reference to a perfect maximum of conceivable smelliness. Therefore there must exist a pre-eminently peerless stinker, and we call him God. Or substitute any dimension of comparison you like, and derive an equivalently fatuous conclusion. That's theology.
The only one of the traditional arguments for God that is widely used today is the teleological argument, sometimes called the Argument from Design although - since the name begs the question of its validity - it should better be called the Argument for Design. It is the familiar 'watchmaker' argument, which is surely one of the most superficially plausible bad arguments ever discovered - and it is rediscovered by just about everybody until they are taught the logical fallacy and Darwin's brilliant alternative.
In the familiar world of human artifacts, complicated things that look designed are designed. To naïve observers, it seems to follow that similarly complicated things in the natural world that look designed - things like eyes and hearts - are designed too. It isn't just an argument by analogy. There is a semblance of statistical reasoning here too - fallacious, but carrying an illusion of plausibility. If you randomly scramble the fragments of an eye or a leg or a heart a million times, you'd be lucky to hit even one combination that could see, walk or pump. This demonstrates that such devices could not have been put together by chance. And of course, no sensible scientist ever said they could. Lamentably, the scientific education of most British and American students omits all mention of Darwinism, and therefore the only alternative to chance that most people can imagine is design.
Even before Darwin's time, the illogicality was glaring: how could it ever have been a good idea to postulate, in explanation for the existence of improbable things, a designer who would have to be even more improbable? The entire argument is a logical non-starter, as David Hume realized before Darwin was born. What Hume didn't know was the supremely elegant alternative to both chance and design that Darwin was to give us. Natural selection is so stunningly powerful and elegant, it not only explains the whole of life, it raises our consciousness and boosts our confidence in science's future ability to explain everything else.
Natural selection is not just an alternative to chance. It is the only ultimate alternative ever suggested. Design is a workable explanation for organized complexity only in the short term. It is not an ultimate explanation, because designers themselves demand an explanation. If, as Francis Crick and Leslie Orgel once playfully speculated, life on this planet was deliberately seeded by a payload of bacteria in the nose cone of a rocket, we still need an explanation for the intelligent aliens who dispatched the rocket. Ultimately they must have evolved by gradual degrees from simpler beginnings. Only evolution, or some kind of gradualistic 'crane' (to use Daniel Dennett's neat term), is capable of terminating the regress. Natural selection is an anti-chance process, which gradually builds up complexity, step by tiny step. The end product of this ratcheting process is an eye, or a heart, or a brain - a device whose improbable complexity is utterly baffling until you spot the gentle ramp that leads up to it.
Whether my conjecture is right that evolution is the only explanation for life in the universe, there is no doubt that it is the explanation for life on this planet. Evolution is a fact, and it is among the more secure facts known to science. But it had to get started somehow. Natural selection cannot work its wonders until certain minimal conditions are in place, of which the most important is an accurate system of replication - DNA, or something that works like DNA.
The origin of life on this planet - which means the origin of the first self-replicating molecule - is hard to study, because it (probably) only happened once, 4 billion years ago and under very different conditions from those with which we are familiar. We may never know how it happened. Unlike the ordinary evolutionary events that followed, it must have been a genuinely very improbable - in the sense of unpredictable - event: too improbable, perhaps, for chemists to reproduce it in the laboratory or even devise a plausible theory for what happened. This weirdly paradoxical conclusion - that a chemical account of the origin of life, in order to be plausible, has to be implausible - would follow if it were the case that life is extremely rare in the universe. And indeed we have never encountered any hint of extraterrestrial life, not even by radio - the circumstance that prompted Enrico Fermi's cry: "Where is everybody?"
Suppose life's origin on a planet took place through a hugely improbable stroke of luck, so improbable that it happens on only one in a billion planets. The National Science Foundation would laugh at any chemist whose proposed research had only a one in a hundred chance of succeeding, let alone one in a billion. Yet, given that there are at least a billion billion planets in the universe, even such absurdly low odds as these will yield life on a billion planets. And - this is where the famous anthropic principle comes in - Earth has to be one of them, because here we are.
If you set out in a spaceship to find the one planet in the galaxy that has life, the odds against your finding it would be so great that the task would be indistinguishable, in practice, from impossible. But if you are alive (as you manifestly are if you are about to step into a spaceship) you needn't bother to go looking for that one planet because, by definition, you are already standing on it. The anthropic principle really is rather elegant. By the way, I don't actually think the origin of life was as improbable as all that. I think the galaxy has plenty of islands of life dotted about, even if the islands are too spaced out for any one to hope for a meeting with any other. My point is only that, given the number of planets in the universe, the origin of life could in theory be as lucky as a blindfolded golfer scoring a hole in one. The beauty of the anthropic principle is that, even in the teeth of such stupefying odds against, it still gives us a perfectly satisfying explanation for life's presence on our own planet.
The anthropic principle is usually applied not to planets but to universes. Physicists have suggested that the laws and constants of physics are too good - as if the universe were set up to favour our eventual evolution. It is as though there were, say, half a dozen dials representing the major constants of physics. Each of the dials could in principle be tuned to any of a wide range of values. Almost all of these knob-twiddlings would yield a universe in which life would be impossible. Some universes would fizzle out within the first picosecond. Others would contain no elements heavier than hydrogen and helium. In yet others, matter would never condense into stars (and you need stars in order to forge the elements of chemistry and hence life). You can estimate the very low odds against the six knobs all just happening to be correctly tuned, and conclude that a divine knob-twiddler must have been at work. But, as we have already seen, that explanation is vacuous because it begs the biggest question of all. The divine knob twiddler would himself have to have been at least as improbable as the settings of his knobs.
Again, the anthropic principle delivers its devastatingly neat solution. Physicists already have reason to suspect that our universe - everything we can see - is only one universe among perhaps billions. Some theorists postulate a multiverse of foam, where the universe we know is just one bubble. Each bubble has its own laws and constants. Our familiar laws of physics are parochial bylaws. Of all the universes in the foam, only a minority has what it takes to generate life. And, with anthropic hindsight, we obviously have to be sitting in a member of that minority, because, well, here we are, aren't we? As physicists have said, it is no accident that we see stars in our sky, for a universe without stars would also lack the chemical elements necessary for life. There may be universes whose skies have no stars: but they also have no inhabitants to notice the lack. Similarly, it is no accident that we see a rich diversity of living species: for an evolutionary process that is capable of yielding a species that can see things and reflect on them cannot help producing lots of other species at the same time. The reflective species must be surrounded by an ecosystem, as it must be surrounded by stars.
The anthropic principle entitles us to postulate a massive dose of luck in accounting for the existence of life on our planet. But there are limits. We are allowed one stroke of luck for the origin of evolution, and perhaps for a couple of other unique events like the origin of the eukaryotic cell and the origin of consciousness. But that's the end of our entitlement to large-scale luck. We emphatically cannot invoke major strokes of luck to account for the illusion of design that glows from each of the billion species of living creature that have ever lived on Earth. The evolution of life is a general and continuing process, producing essentially the same result in all species, however different the details.
Contrary to what is sometimes alleged, evolution is a predictive science. If you pick any hitherto unstudied species and subject it to minute scrutiny, any evolutionist will confidently predict that each individual will be observed to do everything in its power, in the particular way of the species - plant, herbivore, carnivore, nectivore or whatever it is - to survive and propagate the DNA that rides inside it. We won't be around long enough to test the prediction but we can say, with great confidence, that if a comet strikes Earth and wipes out the mammals, a new fauna will rise to fill their shoes, just as the mammals filled those of the dinosaurs 65 million years ago. And the range of parts played by the new cast of life's drama will be similar in broad outline, though not in detail, to the roles played by the mammals, and the dinosaurs before them, and the mammal-like reptiles before the dinosaurs. The same rules are predictably being followed, in millions of species all over the globe, and for hundreds of millions of years. Such a general observation requires an entirely different explanatory principle from the anthropic principle that explains one-off events like the origin of life, or the origin of the universe, by luck. That entirely different principle is natural selection.
We explain our existence by a combination of the anthropic principle and Darwin's principle of natural selection. That combination provides a complete and deeply satisfying explanation for everything that we see and know. Not only is the god hypothesis unnecessary. It is spectacularly unparsimonious. Not only do we need no God to explain the universe and life. God stands out in the universe as the most glaring of all superfluous sore thumbs. We cannot, of course, disprove God, just as we can't disprove Thor, fairies, leprechauns and the Flying Spaghetti Monster. But, like those other fantasies that we can't disprove, we can say that God is very very improbable.
Richard Dawkins is the Charles Simonyi Professor of the Public Understanding of Science at Oxford University. He is a Fellow of the Royal Society, and the author of nine books, including The Selfish Gene, The Blind Watchmaker and The Ancestor's Tale. His new book, The God Delusion, published last week by Houghton Mifflin, is already a NEW YORK TIMES bestseller, and his Foundation for Reason and Science launched at the same time (see RichardDawkins.net).
THE REALITY CLUB:Nikolai Renedo, Patrick Forber, Daniel C. Dennett
by John Brockman
On January 2, 1997, Edge published in its inaugural edition, "Science, Delusion, And The Appetite For Wonder: A Talk With Richard Dawkins", the complete text of the Richard Dimbleby Lecture which he had delivered a few weeks earlier on BBC Television in his role at that time as the Charles Simonyi Professor for the Public Understanding of Science at Oxford University.
Over the years Dawkins has been among the most frequent (and valued) Edge contributors, and our pages are filled with his elegant writing and brilliant thinking. On a trip to England this month, it occurred to me all of his contributions on Edge had been the result either of his public speaking or his writing. I realized that I had never asked him to sit down for a one-to-one videotaped interview. After making arrangements, we met at noon on Saturday, April 11th, in the Enthoven Room of New College to have an Edge conversation. I am pleased to present the video and the transcript below. [ED NOTE: The accompanying soundtrack of the New College bells for the first 22 minutes was not part of the plan.]
THIS IS MY VISION OF "LIFE"
Natural selection is about the differential survival of coded information which has power to influence its probability of being replicated, which pretty much means genes. Coded information, which has the power to make copies of itself—“replicator”—whenever that comes into existence in the universe, it potentially could be the basis for some kind of Darwinian selection. And when that happens, you then have the opportunity for this extraordinary phenomenon which we call "life".
My conjecture is that if there is life elsewhere in the universe, it will be Darwinian life. I think there's only one way for this hyper complex phenomenon which we call "life" to arise from the laws of physics. The laws of physics—if you throw a stone up in the air, it describes a parabola, and that's it. But biology, without ever violating the laws of physics, does the most extraordinary things; it produces machines which can run, and walk, and fly, and dig, and swing through the trees, and think, and produce the whole of human technology, human art, human music. This all comes about because at some point in history, about 4 billion years ago, a replicating entity arose, not a gene as we would now see it, but something functionally equivalent to a gene, which because it had the power to replicate and the power to influence its own probability of replicating, and replicated with slight errors, gave rise to the whole of life.
If you ask me what my ambition would be, it would be that everybody would understand what an extraordinary, remarkable thing it is that they exist, in a world which would otherwise just be plain physics. The key to the process is self-replication. The key to the process is that ... let's call them "genes" because nowadays they pretty much all are genes. Genes have different probabilities of surviving. The ones that survive, because they have such high fidelity replication, are the ones which we see in the world, the ones which dominate gene pools in the world. So for me, the replicator, the gene, DNA, is absolutely key to the whole process of Darwinian natural selection. So when you ask the question, what about group selection, what about higher levels of selection, what about different levels of selection, everything comes down to gene selection. Gene selection is fundamentally what is really going on.
Originally these replicating entities would have been floating free and just replicating in the primeval soup, whatever that was. But they “discovered” a technique of ganging together into huge robot vehicles, which we call individual organisms. An individual organism is a unit of selection in a different sense from the replicator being a unit of selection. The replicator is the unit of selection which strictly is the thing that becomes either more numerous or less numerous in the world. Nowadays we say more numerous or less numerous in the gene pool, and that's modern post-Darwin language.
But because the individual organism is such a salient unit in which these replicators, these genes, have ganged up together, we as biologists tend to see the individual organism as the unit of action. The individual organism is the thing that has legs or wings, it has eyes, it has teeth, it has instincts. It's the thing that actually does something. And so it's natural for biologists to phrase their questions of purpose, of pseudo-purpose at the level of the organism. They see the organism as striving for something, working for something, struggling to achieve something.
What's it struggling to achieve? Well, for Darwin it was struggling to achieve survival and reproduction. Nowadays we would say it's struggling to achieve replication of the genes inside it. And this all comes about because, well, one way of putting it, and I've often put it like this, is to say look backwards at the ancestors of all modern animals, any animals, any time, and you can that the individual is descended from an unbroken line of successful ancestors, an unbroken line of individuals which succeeded in surviving and reproducing. What that really means is they succeeded in passing on the genes that built them. So we are conduits for the genes that pass through us. We are temporary survival machines. Everything about biology can be understood in this way. Everything about biology can be understood if you say that what's really going on is differential replicator survival—gene survival in gene pools—and the way in which they do it is by controlling phenotypes. And those phenotypes in practice are nearly all bundled up into these discrete bodies, individual organisms.
If ever there is a bundle of replicators, a bundle of genes, which passes on its genes to the next generation in a single propagule (we do that: we pass on our genes in sperms or eggs) that means that all the genes in a body, in a mammal body, in a vertebrate body, in an animal body, a normal animal with sexual reproduction. Because all the genes in that body have the identical expectation of getting into future generations, namely leaving the present body in a sperm or an egg, that means that all the genes in a body are pulling for the same end. They all have the same goal.
If they didn't (and some of them might not: viruses, for example, have a different goal of being sneezed out, or being spat out, or whatever it might be) they, of course, are quite different, and they do not cooperate with the rest of the genes in the body. But all the genes that have the same expectation of the future, the same expectation of leaving the present body and getting into the next body, they cooperate. They work together. That's why bodies are such coherent wholes. That's why all the limbs and all the sense organs work together. It's simply because all the genes that built them have the same exit route to the next generation. The minority that don't, things like viruses, they have a different exit route, and they don't cooperate, and they may kill you.
Although it's true that the great majority of survival machines are actually discrete organisms, that doesn't necessarily have to be the case, and if genes can influence phenotypes that are outside the body, then they will do so. This is the extended phenotype. The simplest sort of extended phenotype would be an artifact like a bird's nest. So a bird's nest is an organ, it's an organ in just the same sense as a heart or a kidney is an organ, but it just happens to be outside the body and it happens to be made of grass and sticks rather than being made of the cells that contain the genes. But nevertheless, it's a phenotype, which is produced by the animal's nervous system, working through nest-building behavior. And it does exactly the same kind of thing, namely preserve the genes in the form of eggs and chicks, as organs of the body, like kidneys and livers and muscles.
The next kind of extended phenotype that I talk about is hosts of parasites, because there are these spectacular examples, which Dan Dennett is fond of quoting. For example, of parasites which influence their hosts in order to get into the next host. A host body to a parasite gene is like a bird's nest. It's influenced by the genes. We don't normally put it that way. We normally say that the parasite, the fluke, or whatever it is, the whole fluke influences the whole snail to get itself passed on.
But, in fact, if you think at the genetic level, the genes are influencing the fluke's phenotype, which, in turn, influences the snail's phenotype to enhance the propagation of the fluke's genes into the next generation. So there's no reason to draw a line around the fluke's body and say, well, outside that is no longer proper phenotype. It is proper phenotype, it's just that you have to think outside the box ... in this case outside the fluke ... in order to get the true relationship between genes and phenotypes.
And then generalizing further, a cuckoo in a nest influences the behavior of its host by various stimuli, by having a bright red beak, and squawking in the right way and so on. And once again, just as the fluke influences the snail to get itself passed on to the next generation, the cuckoo influences the reed warbler to get itself, to get its genes passed on to the next generation. And the change in reed warbler behavior can properly be regarded as phenotypic expression of cuckoo genes.
My vision of life is that everything extends from replicators, which are in practice DNA molecules on this planet. The replicators reach out into the world to influence their own probability of being passed on. Mostly they don't reach further than the individual body in which they sit, but that's a matter of practice, not a matter of principle. The individual organism can be defined as that set of phenotypic products which have a single route of exit of the genes into the future. That's not true of the cuckoo/reed warbler case, but it is true of ordinary animal bodies. So the organism, the individual organism, is a deeply salient unit. It's a unit of selection in the sense that I call a "vehicle".
There are two kinds of unit of selection. The difference is a semantic one. They're both units of selection, but one is the replicator, and what it does is get itself copied. So more and more copies of itself go into the world. The other kind of unit is the vehicle. It doesn't get itself copied. What it does is work to copy the replicators which have come down to it through the generations, and which it's going to pass on to future generations. So we have this individual / replicator dichotomy. They're both units of selection, but in different senses. It's important to understand that they are different senses.
Now, because the individual organism is such a salient unit, biologists after Darwin got into the habit of seeing the organism as the unit of action, and therefore they asked the question, what is the organism maximizing? What mathematical function is the organism maximizing? Fitness is the answer. So fitness was coined as a mathematical expression of that which the organism is maximizing. Of course, what fitness really is, or what it ought to be if we understand it properly, is gene survival. For a long time fitness was equated in people's minds with reproduction, with having a large number of children, grandchildren, great-grandchildren. Bill Hamilton and others, but mostly Bill Hamilton, realized that you had to generalize that because, if what's really going on is working to pass on genes, offspring, grandchildren, et cetera, are not the only ways of passing on genes. An organism can work to enhance the survival and reproduction of its siblings, its nephews, its nieces, its cousins and so on. Hamilton worked out the mathematics of that.
I think it was unfortunate that Hamilton, having realized this very important insight, chose to stick with the individual organism as the entity of action. He therefore coined the phrase "inclusive fitness", as the mathematical function which an individual organism will maximize if what it's really doing is maximizing its gene survival. It's a rather complicated thing to calculate. It's difficult to calculate in practice and this has led to a certain amount of, not hostility, but a certain amount of skepticism about inclusive fitness as a measure, skepticism which I share. But for me the remedy of that skepticism is to say, well, forget about the organism and concentrate on the gene itself. Ask yourself (as Hamilton also did) ask yourself, if I were a gene, what would I do to maximize my propagation into the future? Hamilton did that, but he also, I think, later took a sort of false trail (it's strictly correct but not helpful) by saying if I'm an individual, what would I do to maximize my gene survival? Both ways of phrasing it are correct, they're both correct if you can get the calculation right, but one of them is rather harder to do. If you're trying to do intuitive Darwinism, if you're trying to work out what would you expect to happen in the world, I think it's better to ask the question, what would I do if I were a gene, rather than what would I do if I were an elephant?
In both cases this is a personification. Nobody really thinks that either genes or elephants scratch their heads and think, what would I do; but it's a useful trick, a useful dodge when you're trying to get the right answer as a field biologist in the Serengeti. It's a useful trick to say what would I do if I was a ... and you could fill in the end of that sentence by saying either if I was a gene or if I was an elephant. And you'll get the right answer if in the gene case you concentrate on self-replication and if in the elephant case, you concentrate on passing on genes. So we have these two logically equivalent ways of expressing what's going on in Darwinism. Both of them Hamilton used. There is the what-would-I-do-if-I-was-the-gene way of doing it, and there's the what-would-I-do-if-I-was-an-elephant-or-an-aardvark way of doing it and they're both correct. I think some of the opposition to Hamilton, which has recently surfaced, is because people have realized that inclusive fitness is not a very practical way of doing things. It's a difficult thing to calculate. And my suggestion would be (and I actually said this to Hamilton) my suggestion would be to abandon inclusive fitness and to concentrate instead on personification of the gene and then you'll get the right answer.
George C. Williams in 1966 wrote a brilliant book, Adaptation and Natural Selection, roughly at the same time as Hamilton was working, and they both tumbled to the same truth, which is that what's really going on in natural selection is survival of genes. Williams was eloquent on this. Williams said things like, Socrates may have had any number of children, we don't know that, but what Socrates really passed on, if he passed on anything, was genes. It's genes that pass through the generations. And so whenever you're talking about teleonomy, whenever you're talking about the pseudo-purpose, which is what we see in life, what's it for, what's the adaptation for, who benefits, cui bono, whenever you ask that question you should be looking at the level of the gene. Williams realized that, Hamilton realized that.
In The Blind Watchmaker, I wanted to get across the idea that cumulative selection can give rise to immense complexity and dramatic changes. So I wrote a computer program for the Macintosh, which presented on the screen a range of phenotypes which were built by an algorithm which I called its embryology, which was actually a tree-growing algorithm. And the shape of the tree was governed by genes. There were nine genes I think in the first version, and so what the user saw on the screen was a "parent", as I called them, in the middle, and eight [actually fourteen, misremembered as eight in the interview] other biomorphs around it were the offspring. They were built by genes which were nine numbers. The genes could mutate by either having a small amount added to their value or a small amount subtracted from their value. So all the nine biomorphs looked a bit different, were obviously descended from the same parent, but they were a little bit different. And you could choose with a mouse which one to breed from, it glided to the center of the screen, produced fourteen offspring and so on. It went on and on through generation after generation. You could breed anything you like. It was a most extraordinary experience to breed massively different shapes from the original by gradual degrees, and they came out looking like insects, and flowers and all sorts of things.
I'm pleased to note that although I’d thought I’d lost these biomorphs, because modern Macs don’t run the software that old Macs do ... a wonderful man called Alan Canon in Kentucky wrote to me and said he wanted to revive them. So I sent him all my old Pascal code, which would no longer run, and he’s now hard at work producing phoenix from the ashes—my old programs—and I’m simply delighted by this.
I then went to the Artificial Life Conference, organized by Chris Langton, and I gave a talk called "The Evolution of Evolvability", which I think was the first time the phrase had ever been used, and it's being used quite a lot.
The original biomorph program had nine genes. I then later enlarged it to 16 genes. I added genes that did things like segmentation, that had biomorphs that were arranged serially along the body like a centipede which has lots of different segments, or like a lobster which has lots of segments, but each segment can be a little bit different. I had genes that had symmetries of various kinds. So I increased the number of genes from nine to sixteen and the repertoire of biomorphs that became possible to breed then dramatically increased. It was still limited, but nevertheless it increased. And it occurred to me that this was a good metaphor for radical changes in embryology that happened at certain important times in evolution. For example, I just mentioned segmentation. The very first segmented animal had some kind of major mutation, which gave it two segments instead of one, I'm guessing. It may have been three. It can't have had just one and a half segments. There must have been at least two. It duplicated everything about the body. If you look at the body of an earthworm or a centipede, it's like a train, like a truck. Each truck is similar to the neighboring trucks and may be identical.
Before the origin of segmentation in the ancestors of earthworms, or the ancestors of centipedes, the ancestors of vertebrates, animals must have evolved as just one single segment, and they would have evolved in the same sort of way as my biomorphs did when they had only nine genes. Then the first segmented animal was born. It must have been radically different from its parents. This must have been a major mutation. And as soon as the first segmented animal was born with two segments, the same as each other, probably ... it wasn't a difficult thing to do in one sense because all the embryological machinery to make one segment was already there. And so to double it would have been obviously a major step. Nevertheless, all the machinery is there. It's not like inventing a whole new organ, like an eye. That cannot happen. It's got to happen by gradual cumulative selection, which is the main message of The Blind Watchmaker. But once you've got the machinery to make an eye, or to make a vertebra, or to make a heart or anything like that, you could make two because the machinery is already there. That's what segmentation is.
And so when segmentation was invented by some kind of macro mutation, a whole new flowering of evolution became possible and vertebrates, arthropods, annelids, all exploit this new embryological trick of segmentation. And I illustrated this with my biomorphs because when I added the segmentation gene for the macro mutation, which I actually had to program in, when I added it, it meant that a whole new flowering of morphology could appear on the screen. You could evolve much more exciting animals because segmentation was there. Similarly with the genes for symmetry. I had genes doing kind of mirror image morphology in two different planes. And immediately I started being able to breed things like flowers, butterflies, beautiful creatures.
The evolution of evolvability, then, is an evolutionary change which makes a radical alteration in embryology, and that opens up floodgates of further evolution which were not possible before. Segmentation is one example, sex may be another one. Torsion in mollusks may be another one. These are major changes, which I think are rare. They may happen once every 100 million years, but there's kind of normal evolution which goes on by the normal cumulative, slow, gradual process that we mostly teach about. But every now and again I suspect there's a major jump, a macro mutation which opens up new floodgates, and segmentation would be the best example. I was really led to think about this by the addition of seven more genes to my original nine gene biomorph, and that's what I talked about at Chris Langton's Artificial Life Conference, and I called it "The Evolution of Evolvability".
I incorporated these ideas of evolution evolvability in Climbing Mount Improbable, which is a bit similar to The Blind Watchmaker, but has a lot more in it. And by then I'd added a whole lot more genes, in this case introducing colors, and we now have color biomorphs. And perhaps rather more interestingly, I teamed up with Ted Kaehler. He was one of Apple's star programmers. I met him at the Artificial Life Conference. And after that we collaborated on a new project which I called "Arthromorphs", which was somewhat similar to biomorphs, but with a totally different kind of embryology, and much more based upon segmentation, and much more based upon especially arthropod segmentation. And the arthromorph program didn't require the programmer, namely me, to introduce the new watershed changes, the new macro mutations which led to new flowerings of evolution. It happened internally, it happened in the computer. They really were macro mutations. That was a big step in my use of computers in both understanding and teaching about evolution.
One of the things that I've always done is not make a clear separation between books that are aimed at popularizing, books that are aimed at explaining things to other people, and books that explain things to myself, or explain things to my scientific colleagues. I think the separation between doing science and popularizing science has been overdone. And I have found that the exercise of explaining to other people, which I suppose I've been fairly successful at, is greatly helped by the fact that I first have to explain it to myself. And explaining it to myself ... the biomorph program, which I originally wrote to explain to students, and I used them in student practicals ... led me to think anew for myself, stimulated me to understand much better about evolution, stimulated me to understand about the evolution of evolvability in a way that I haven't before.
Nobody knows whether there's life elsewhere in the universe. I think there probably is. The number of stars in the universe is something like 1022, and most of them have probably got planets. It would be pretty astonishing if we were unique. It would go against the lessons of history, you know, we're not the center of the universe, et cetera. Science fiction writers try to speculate about what life elsewhere might be like. I have one contribution to make, which is that I think however weird, and alien, and strange, and different life elsewhere might be, we can say one thing about it, which is that it will be, if we discover it, it will turn out to be Darwinian life.
I think there's only one way for the lead of pure physics to be transmuted into the gold of complex life, and that is differential replicator survival, which is Darwinism in its most general sense. So I would stick my neck out and say that when and if we ever discover life elsewhere in the universe, it will be Darwinian, it will be based upon something like DNA, probably not DNA, but something like DNA in the sense of an ultra-high fidelity, self-replicating coding system with the capability of producing great variety, which is what DNA does. So what I call universal Darwinism is the doctrine, almost, the one thing we know about life everywhere, is that it's Darwinian life.
I gave a talk called "Universal Darwinism" at one of the Darwin Centenary Conferences, the one in Cambridge, and I based it upon looking at all the alternatives that someone might have suggested like Lamarckism, inheritance of acquired characteristics, the principle of use and disuse. The point I tried to make is that contrary to what most biologists have said, the thing that's wrong with Lamarckism is not just that it doesn't work in practice, that acquired characteristics are not as a matter of fact inherited. There are biologists, including Ernst Mayr who have said Lamarck's theory is a fine theory, but unfortunately acquired characteristics are not inherited. The point I made was that even if they were inherited, the Lamarckian theory is nothing like a big enough theory to do the job of producing complex adaptations. Lamarckian theory depends upon use and disuse. The more we use our muscles, the bigger they get. That's fine, that happens, and then inheritance of acquired characteristics, you pass on your bigger muscles to your children. Ernst Mayr said that's a perfectly good theory. The only trouble is it doesn't work because acquired characteristics are not inherited, which of course, is true.
But the point I was making was that even if it was true, the principle wouldn't work to produce real interesting biological evolution. Muscles are fine, that's one thing that does grow bigger when you use them. But something like an eye, the delicate focusing mechanism of the eye, the transparency of the eye, the huge number of light-sensitive cells, three different color coding and so on, that doesn't come about by use and disuse. The more you use your eyes, they don't become more—the lens doesn't become more transparent as photons wash through it. The eyes become better because every single tiny mutation that improves the eye. As Darwin said, nature is daily and hourly scrutinizing. So every little tiny change, no matter how deeply buried in internal cellular biochemistry it is, if it has any effect whatever on survival and reproduction, natural selection will pick it up. The Lamarckian principle will work only for very, very crude growth, things like muscles getting bigger when you use them.
As we look around the world in which we live, what we see is stupefyingly complicated manmade machines like this camera that you're filming with, this recording machine, this computer, cars, ships, planes. These are not produced directly by natural selection, these are produced by human ingenuity, by human brains working together. No one human can make a Boeing 747. I mean, this is a cooperative enterprise involving lots of humans, involving lots of computers. It's a fantastic extension of the Darwinian substrate. So the principles that give rise to the very strong design of a plane, or a car, or a computer, these all come from human brains. But that's not the ultimate explanation. The human brains themselves have to come from Darwinian natural selection. So if we go to other planets and discover extremely complicated technology, that technology itself will be the direct product of Darwinian selection, but it will be the product, ultimately, of Darwinian selection of the brains ... whatever they call them on that planet. It's arguable that something ... this is a different kind of argument now ... it's arguable that something like Darwinism does go on in human technology: that when a human designer is designing on the drawing board, he designs something, doesn't like it, tosses it in the bin, gets a fresh bit of paper, designs a slight variation of it and so on. There might be a Darwinian element to that. That's not what I'm saying.
I'm saying that a wholly new, at least partly new, kind of design came into the world when human brains started to exercise ingenuity, especially social ingenuity, cultural ingenuity. But the ultimate source of that is evolved brains, and the evolved brains have to come about by some version of Darwinian selection, which on other planets might be very different, but it will still be, I conjecture, I bet my shirt on it being Darwinian.