When a Young Richard Dawkins Proved Evolution to Young Earth Creationists

本站添加: 2026-05-28

[00:00:00]Charles Darwin himself said, "To this day, the eye makes me shudder."

[00:00:04]Creationists are particularly fond of the eye because they like saying, "What is the use of half an eye? An eye only works, they say, if every little detail is in place. Until you got that, the eye won't see anything at all. So, how could it possibly have evolved?" Evolution is the one idea that has nothing to fear from the 747 argument because evolution is the one idea that does not suggest that complex perfection came into being in a single step.

[00:00:28]It is the theory of miraculous creation that is really blown out of the water by the 77.

[00:00:34]Here are a couple more.

[00:00:36]Here are a couple more. There's a branch of a tree.

[00:00:41]It seems to be moving.

[00:00:44]There's goes its head. It's a bird.

[00:00:46]Flies off. A potu. Those are rose thorns.

[00:00:50]That's not a rose thorn. It's a bug. It gains protection by looking like a rose thorn.

[00:00:57]You could almost say that it's like a key that fits into the brain of a bird and the bird mistakes it for a thorn.

[00:01:07]The bird has a rose thorn shaped lock.

[00:01:11]If that sounds a little bit mysterious, I hope I'll explain it in a moment because I'm going to use the analogy of a lock and key. Whenever we see an apparently well-designed animal or plant, it's as if nature has the lock and the creature has the key.

[00:01:28]The thing about a lock and key is that the key has an intricate structure which is very hard to imitate and that structure exactly fits the lock.

[00:01:40]This key fits precisely into the lock and the holes in the key fit the teeth in the lock and the lock therefore opens. Just any old bit of bent wire won't do. It has to be the right key.

[00:02:01]The principle of the lock and key is that there's something intrinsically improbable in the shape of the key. You need that key to open the lock.

[00:02:09]In the case of an ordinary lock that you open with a key, it's not easy to measure how improbable the key is. But here's a combination lock, an ordinary bicycle lock. Here we know exactly how improbable it is because there are three dials and each one has six positions.

[00:02:27]That means there are 6 * 6 * 6 possibilities, which is 216.

[00:02:34]There's a 1 in 216 chance of opening it by luck.

[00:02:38]And here's a model of the same combination lock so we can see how it works.

[00:02:46]You have to get all three of the dials into position. This one's combination is six, five, one, and the lock opens. All three of the teeth have to be lined up. It isn't enough just to have one of them.

[00:03:06]But the lock is just a parable. Let's get back to real life. If the thorn bug is a key, what this means is that just any old shape won't do. It must be the exact shape of a rose thorn. A stick insect must be the exact shape of a stick. An upper tooth must fit bite snugly against the lower teeth in your jaw.

[00:03:30]Yet the theory of evolution says that all these things evolved gradually stage by stage. This means that they must have gone through intermediates when they were not a perfect key fitting a lock.

[00:03:44]The thorn bug must have been half like a thorn. The stick insect must have been half like a stick. But who ever heard of a key that only half fitted a lock? A key either fits a lock or it doesn't.

[00:03:59]So, how do real living creatures manage to evolve their perfection? How do they manage to survive the intermediate stages? How do they work when they're only half a key?

[00:04:10]Well, let's approach the problem by going back to the combination lock.

[00:04:14]While I've been talking, Bryson's been discreetly doctoring his lock so that it behaves in a different way.

[00:04:25]If you could imagine a lock where instead of having to get all the dials in place at once, supposing I was trying to crack a safe and there was money in there. As it is, I can't do it because I've got to get all the dials in place at once and I've only got a one in in 216 chance of doing that. In a real bank safe, it would be one in billions. I can't do it. But suppose that I were able to try the first one at random and eventually find how to open that. And then the safe door peeps open a little bit and a little bit of money drops out. I've done that one.

[00:04:59]Now I can go on to the next one. And I find out where how to open that one.

[00:05:04]I've only got a one in six chance.

[00:05:05]That's fine. And a little bit more money spills out. And now the final wheel.

[00:05:10]I've only got one in six chance. That's easy. And I open the entire safe. It's now become a gradualistic combination lock. Whereas before it was an all or nothing combination lock.

[00:05:27]With this lock, the maximum number of tries that you need in order to open it by luck is not 216 but a mere 18.

[00:05:37]So it's easy to open a gradualistic combination log. And I call this smearing out the luck because we don't have to get our luck all in one ridiculously large dollop. Instead, we can get our luck in dribbs and drabs.

[00:05:52]Each dribb being allowed to count before the next drab, and we go on to wait for the next bit of luck. It accumulates.

[00:06:01]So, what have we seen so far? Although an animal may look like a key fitting along, it's not a totally good analogy because in this case, half a key is better than no key. If nature is a combination lock, it's a gradualistic combination lock, not an all or nothing one.

[00:06:20]Now, let's look at the same thing from another direction. It's been said that a monkey typing at random on a typewriter could eventually write the complete works of Shakespeare. Well, I once did this experiment with my then 11-month-old daughter Juliet. And uh this is what she typed. I let her go for a bit and so on and so on. And I realized after a bit that I'd have to let her go on for at least a billion years before she got even a single phrase of Shakespeare.

[00:06:51]The eminent astronomer Sir Fred Hy has pointed out that it's just about as unlikely that any complex living structure could spring into existence suddenly by luck alone. He said it's rather like taking a junkyard and letting a hurricane blow through it. and the Huracan has the luck to spontaneously assemble a Boeing 747.

[00:07:18]So, here's our junkyard and the Huracan comes along and it blows like this. And Hil's point is that the luck that would be necessary to spontaneously assemble a Boeing 7447 like that is equivalent to the luck that you would need in order to get something like an eye or a stick insect or a hemoglobin molecule by sheer luck.

[00:07:42]Well, my reason for mentioning H oil 747 is that I'm going to take his name in vain in the next demonstration.

[00:07:50]We're going to have a computer monkey, or rather we're going to have two computer monkeys, one called Hy and one called Darwin.

[00:07:59]Both monkeys have the same task. both have to to type not the complete works of Shakespeare but one phrase from As You Like It, More Giddy in My Desires than a Monkey.

[00:08:13]Hy types entirely at random. After every line that he types, the computer checks to see if he has managed to hit the target line. If he does, the computer will stop. Bells will ring. It'll be the most improbable coincidence in the history of the world. And I solemnly promise to eat my hat.

[00:08:36]I'll go further than that.

[00:08:39]I bet you everything I possess that it won't reach the phrase, less, shall we say, in the next 10 billion years. I won't bet you. I'll undertake to give everything I possess to the Royal Institution. And here's a legal document signed by me which undertakes to make over everything I own to the Royal Institution in the event that the monkey hoil reaches the target phrase. But of course, this is just to illustrate my confidence that chance on its own could never make an eye or a 747.

[00:09:08]>> The perfect design argument sounds strong until you look at the science.

[00:09:13]Eyes did not need to appear fully formed. A simple light sensitive spot helps an animal detect danger. A curved spot helps detect direction. A deeper cup sharpens vision. A lens improves focus. Every step gives a survival advantage. That is exactly how natural selection works. The Bible says life was created in fixed kinds. But biology shows shared ancestry, mutation, and selection over time. The evidence supports evolution, not instant creation. Literal creationism fails because it has belief. But evolution has the fossils, genetics, and living examples.

[00:09:54]>> The real point of the demonstration is that the other monkey, Darwin, will get the target phrase. So, what does Darwin do? The same, but with a crucial difference. The Darwin monkey begins by typing a random phrase. So far, it's the same as the Hoy monkey. But now the computer breeds from that phrase. It breeds 50 offspring which are identical to the first phrase but with a tiny mutation, a tiny random difference in each of the 50 cases. The computer then looks at those 50 offspring and chooses the one which most resembles the target phrase, however slightly it resembles the target phrase. So the generations go by and after generation after generation it gradually becomes more and more like the target phrase. Now when I uh agreed to give these lectures I was told that I should always call members of the audience out to assist. But I was also told that it was silly to do this if all I was going to ask them to do was to come out and hit the return button on a computer.

[00:10:59]However, on this particular occasion, since so much is at stake, I thought it would be better if I did ask somebody who knows a lot about computers and is very good at pressing buttons to come out and perform this ownorous task. So, would anybody like to volunteer to Yes.

[00:11:13]Right.

[00:11:19]>> Now, you what's your name?

[00:11:21]>> Andrew.

[00:11:22]>> Andrew.

[00:11:23]>> Will you understand what's at stake at stake, Andrew? Do you Okay. Here's the target phrase. is more giddy in my desires than a monkey. There's the box where the hoy monkey is going to type.

[00:11:33]And there's the box where the Darwin monkey is going to type. And unless Bryson's been messing around with the program in order to deprive me of my worldly goods, that's the way it's going to be. So, are you ready? Go.

[00:11:50]Now, you see the Hil monkey typing away entirely at random. The Darwin monkey is down here. And I think we can begin to see something appearing in the Darwin row. More if giddy in my desires than bang. And it's got there. How long did that take? Anybody time it? Not very long, I think. Anyway, thank you very much.

[00:12:22]So I don't have to eat my hat and my worldly goods such as they are are safe.

[00:12:26]But the point really is not that H oil failed to reach the target. The point is that Darwin did reach the target and astonishingly quickly. Well, there's a lot wrong with that as a demonstration of Darwinian natural selection. For one thing, it has a distant target in mind which natural selection does not have.

[00:12:42]But it does once again show us the key to the way out of the problem of mammoth improbability. Things like eyes and 747s that couldn't possibly spring into existence in a single lucky shake of a dice can come into existence if the luck is smeared out in many tiny steps and is accumulated. And that's what this lecture is about. Smearing out the luck, accumulating it turns out to be an immensely important process. It's the process that makes it possible for us to be here. And by us, I mean all stick insects, lions, elephants, and bacteria.

[00:13:18]everything that's here. And now let's look at a physical parable for this gradualistic solution to a difficult problem. This is a mountain. It's called Mount Improbable.

[00:13:32]Sitting on the top of the mountain is equivalent to being very welldesigned, to being an eye that works very well.

[00:13:40]For example, being at the bottom of the mountain is equivalent to being a distant ancestor that is not yet very well designed, that hasn't yet acquired its good fitness to the environment.

[00:13:52]Looking facing you now is a precipice, a cliff, which is called sheer luck. It's a sheer cliff.

[00:14:02]Jumping from the bottom of the cliff to the top corresponds to assembling a 747 by means of a hurac or it corresponds to getting a complete eye in a single lucky mutation. It can't be done. You can no more do that than a mountaineer could leap from the bottom of a of a cliff to the top.

[00:14:22]But this isn't the only route up Mount Improbable. We have to go round the other side.

[00:14:34]And you'll notice that round here is a gradual sloping path steadily inching its way up the mountain. And if you follow it round, you'll find that even though some bits of it are a little bit steep, you can get from the bottom to the top without ever having to jump up a step. It's a gradual inchby-inch path up.

[00:15:01]Anybody who didn't know about the ramp evolution, which is what that's called, would if they saw an animal perched on the top, a beautifully designed animal, and only saw the cliff, they would assume that it had to be the result of a miracle.

[00:15:22]But in fact, the only way up Mount Improbable is the slow gradual climb up the ramp evolution. You have to add all the little steps up together, and after a very large number of steps, you can climb very, very high indeed.

[00:15:37]But we're still talking in parables. How in practice do living things climb Mount Improbable?

[00:15:44]Well, of course, individuals don't climb it. its lineages, groups of animals, species that climb it. And they do it in evolutionary time, they and their descendants and their descendants descendants. They do it by going through an extremely large number of generations. And we do have the time for an extremely large number of generations because we have geological time at our disposal.

[00:16:09]This generation bygeneration accumulation works only if there is reproduction with true heredity to carry the message through. And I must explain what that means because just plain reproduction without heredity won't do.

[00:16:24]It's not enough. It's possible to imagine reproduction without heredity.

[00:16:29]Fires, for example, have a form of reproduction without heredity.

[00:16:35]If you imagine that this is a savannah, a dry savannah with dry grass all over it and a fire suddenly starts in one place.

[00:16:47]Sparks fly up and are carried in the wind and suddenly a spark lands there and a new fire starts. Both these fires are now flaming up and sparks are going off and another fire starts up which may be the daughter of this one. One starts up here which may be the daughter of that one. These fires are propagating.

[00:17:04]These fires are having children. The sparks are causing this fire to be the parent of that one. And in the next one, we can see that you can have both not mother and daughter, but grandmother grandchildren fires.

[00:17:23]Now, the fires may differ a bit. In this picture, we've represented them by red, green, and blue. Fires may indeed differ, but they get their qualities not from their parents and grandparents. A fire gets its qualities from its surroundings, from its environment. A fire gets its qualities from the direction of the wind where it happens to be or from the chemistry of the soil or from the dampness of the vegetation.

[00:17:49]Fires do not get their qualities from the spark that comes from their parent fire. Creationists love to say complexity is too unlikely, but that argument ignores selection. Random mutation alone does not build an eye.

[00:18:04]Mutation creates small changes. Heredity passes them on and natural selection keeps the useful ones. That is why the pure chance attack fails. Evolution is not a tornado building a jet. It is tiny advantages stacking over millions of generations. The fossil record, genetics, and living animals all point the same direction. Life changes through descent with modification.

[00:18:30]Genesis gives a story. Biology gives a mechanism. The mechanism wins.

[00:18:36]>> Now, we're going to do the same thing with a Bryson special.

[00:18:41]And I'm going to stand well back, I think. Where where do I have to stand?

[00:18:43]Here.

[00:18:45]Right.

[00:18:46]>> We always have to have fireworks at the Royal Institution. So go ahead, Bryson, please.

[00:18:52]Right, there's the first fire. There's the parent fire. The sparks are flying up. I'd started another one there.

[00:18:58]That's the daughter fire and a granddaughter and a second daughter of this one.

[00:19:13]But the point is that to the extent that there are any differences between these fires, they do not get their qualities from their parents.

[00:19:24]There are sparks that flow from fire to fire. The all that the sparks do though is to start a new fire. Nothing is carried in the spark. There's no information carried in the spark.

[00:19:50]And this of course this is where rabbits and humans and stick insects differ from fires.

[00:19:57]Don't be misled by the way by the fact that rabbits and humans have a mother and a father. Stick insects only have a mother like fires. In this particular respect stick insects are like fires.

[00:20:06]But in the important respect that I'm talking about, stick insects do not resemble fires.

[00:20:14]Because unlike fires, stick insects have true heredity.

[00:20:19]At least some of their qualities, color, shape, size, spininess, and so on, they actually get from their mother and not only from their surroundings. Something travels from mother to daughter.

[00:20:30]Something in the spark that travels from mother to daughter, there is information.

[00:20:35]So, what is this mysterious information that eggs contain and sparks don't?

[00:20:41]Well, it's DNA. This astounding molecule which contains in the sequence of its bases all the information or almost all the information that you need to build a stick insect or a rabbit.

[00:21:05]DNA comes like an everflowing river down the generations.

[00:21:11]The river of DNA that flows through us into the future is a pure river that leaves us exactly as it finds us with one exception.

[00:21:23]There are occasional very occasional random changes called mutations.

[00:21:29]Because of these there is variation, genetic variation in the population and that opens the way for natural selection. Those varieties of DNA that just happen to be good at building ancestors, at building bodies that have good eyes, good legs, good anything else survive. So the world automatically becomes filled with good DNA. This means good at making bodies that are themselves good at surviving.

[00:21:58]This is the Darwinian explanation for why living things are so good at doing what they do. They are good because of the accumulated wisdom of their ancestors. But it's not wisdom that they have learned. It's wisdom that they chanced upon by luck. Lucky random mutations which were subsequently selected. And in each generation, the amount of luck was very small.

[00:22:24]But because the luck has been accumulated over so many generations, we are impressed by the end product.

[00:22:32]Now I want to apply this lesson to three particular cases, three particular problems that have given difficulty. The eye, the wing and camouflage. And I choose them because they are famously regarded as difficult. First, the eye.

[00:22:48]Charles Darwin himself said, "To this day, the eye makes me shudder."

[00:22:54]Creationists are particularly fond of the eye because they like saying, "What is the use of half an eye? An eye only works, they say, if every little detail is in place. Until you've got that, the eye won't see anything at all. So, how can it possibly have evolved?"

[00:23:08]And even serious scientists have sometimes queried whether there's been enough time for the evolution of the eye.

[00:23:16]Well, suppose we start with an ancestor who didn't really have an eye at all, but just a single simple sheet of light sensitive cells. That's represented by this screen here. And there's a television camera behind looking at the screen so that we on the screen on the television screen shall see what this primitive animal would see.

[00:23:39]So this animal with hardly any eye at all will at least be able to tell the difference between light and dark.

[00:23:48]Light and dark.

[00:23:55]Now the next stage in evolution would be to have a shallow cup.

[00:24:05]This animal would be able to tell the direction that light is coming from because there a shadow would appear.

[00:24:18]A shadow would appear there. And if you can tell the direction a light is coming from, then you can tell the direction that a predator is coming from. Now although we've represented this as a cup coming out from the wall, it would in fact probably be an indentation and it would be a gradual indentation. It's inconvenient to make a gradual indentation. It has to be made as a rather abrupt cup that comes out 6 in at a time. But it's easy to see that that shadow effect that we've just been witnessing would work progressively and gradually as the cup gets bigger. Let's make it bigger still now. Bryson and this cup is even more effective.

[00:25:01]And if we go on to the next stage where we make the cup gradually bigger again so big that it becomes just a little hole in the end.

[00:25:17]Right now, this animal has a very good idea of exactly where the light is and by the same token exactly where, for example, a predator is. And I think with this eye, we might even get a little image. See if we can get an image of Bryson's hand. That smudge there is Bryson's hand. And you can just about see a very dim image of his fingers. So, an animal with an eye like this would be able to see perhaps just a little bit what kind of predator it was. Let's go to the logical conclusion which would be a pinhole.

[00:25:51]Remember this is all gradual gradual change in evolution. Right? Let's see if we can see your hand again Bryson.

[00:25:58]Now I can see a rather precise picture of Bryson's hand. It's not a very bright one but I can see every finger clearly delimited. So I could see if I were this animal I could see my predator in some detail.

[00:26:12]Living things are not like fire because fire does not pass down instructions.

[00:26:17]Life does.

[00:26:19]DNA carries information from one generation to the next and small mutations create variation. If a change helps survival, it can spread. That is how eyes improve over time. Light sensitive cells become a cup. The cup detects direction and a pinhole starts forming a real image.

[00:26:39]Religion says design came first. Biology shows instructions, mutation, selection, and inheritance doing the work.

[00:26:52]There is an animal that has a pinhole camera for an eye. It's a mollisk called nautilus.

[00:26:59]It's a relative of the octopus, but it lives in a shell. And there is its eye.

[00:27:04]just has a simple hole and seawater can flow in and out of that hole.

[00:27:11]Here's a shell of nautilus.

[00:27:15]This bit of rock here shows ammonites which are a now extinct relative of nautilus. They were once immensely common as this rock suggests.

[00:27:27]I like to think of all those hundred million-year-old dramas that must have been witnessed through the pinhole camera eyes of Ammonites. We can't be sure they had pinhole camera eyes, but it seems quite likely.

[00:27:42]Now, a pinhole camera is not a very good way of seeing. It does produce a sharp image, but because it's so narrow, you hardly get any light in. The answer to this problem is that ingenious device, the lens.

[00:27:56]Nautilus has a pretty poor eye compared with its relatives, the squids and octopuses, because they do have a lens.

[00:28:02]And so we can't help wondering why doesn't Nautilus have a lens? Why didn't it evolve a lens? Well, I suspect that Nautilus may have got itself stuck on a little peak some way up Mount Improbable.

[00:28:19]You see that although we've got one big peak there, there are various other peaks on the way. There are quite a lot of them. And since the rule in evolution is just to keep going uphill, when the ancestors of Nautilus came up the track here, up the path here and got to this point, that way uphill look just as inviting, so to speak, evolutionarily as that way. Both of them were uphill. Evolution has no foresight.

[00:28:46]Evolution has no way of knowing that if you travel up that way, you're going to end up with a lens. For the moment, this appears to be a perfectly good way to travel because the pinhole camera at this level of illumination is an effective eye. So, I wonder whether perhaps Nautilus has got itself trapped on top of this little hillock and is now unable to escape because escaping would mean going downhill into the valley. And the one thing you cannot do on Mount Improbable is ever go downhill.

[00:29:17]But let's imagine what the ancestors of the squid and octopus did when they got to this junction point here. They just happened to go on up this way and they started evolving a lens and we did at a different time in history.

[00:29:34]How might the lens have evolved? Well, let's imagine that it started with just a single transparent sheet of some transparent material. And all that this was doing, it's not a lens yet. All that it's doing is protecting the eye. In Nautilus, seawater flows right inside the eye. This animal now has some protection. And the eye is really just the same as as though there wasn't any transparent material there.

[00:30:02]Now, we're going to use an uh optition set of lenses here. It would be nice to be able to have just one bit of transparent material, which we would then squeeze and make thicker, but we can't do that. So, we're going to replicate that effect by a whole series of little lenses. So, this is the next stage in evolution. This animal here, let's get an image of that.

[00:30:24]Okay, that's a rather better and above all brighter image of the hand. Let's have the next lens in.

[00:30:36]Right now, if an animal that had an eye like that would have a really very very clear view of its world, it could tell exactly uh what its predator was, would anybody like to come out and have their face looked at?

[00:30:48]>> Right. Yes.

[00:30:50]What's your name?

[00:30:51]>> Deina.

[00:30:52]>> Say to him, >> Deina.

[00:30:53]>> Deina. Now, can did you remember where Bryson put his hand? Can you put your face just down there? We need the lights down, I think, for this, don't don't we?

[00:31:03]There we are. Very nice. This this animal can even see what its predator's face looks like upside down. But we all see upside down.

[00:31:13]Thank you very much, Deina.

[00:31:22]So, we have a gradual pathway all the way up Mount Improbable from no eye to an eye. But has there been enough time for the evolution of the eye?

[00:31:34]Well, recently a Swedish scientist called Dan Nielson has tried to answer that question. He did pretty much the same as we've just been doing here, but he did it with a computer. So, instead of growing up in big steps as we had to do with our wooden model, he was able to do it in very small steps on his computer. In fact, very small steps indeed. deliberately. He assumed that each step which means each mutation caused only a 1% change in the size of something like say the steepness of a cup.

[00:32:07]He also devised a way of measuring the efficiency of an eye. He did this by telling the computer to measure various things about the eye that it had just drawn itself. And then the computer worked out using the rules of physics how good an image that I would be capable of producing.

[00:32:27]And the question was with those rules built into it, would there be a smooth gradient of improvement, starting out with a flat retina and ending with a proper eye like ours? And you've guessed it, the answer is yes. This was Neielson's starting point with just a flat retina under a flat transparent layer. And now let's just run the simulation of these are the successive stages that Neielson got. And they're pretty similar to the successive stages that Bryson got with his model.

[00:33:02]So so far we haven't learned anything that we didn't already know. There is a smooth progression up Mount Probable for the eye. But Neielson went on to estimate how many generations it would take to accomplish this evolution.

[00:33:19]In order to do this, he had to make some more detailed assumptions. I won't bother you with exactly what they were.

[00:33:25]All you need know is that they were quantities which geneticists out in the field can measure and have measured. And Neielson put into his computer model values of these quantities that were conservative. Conservative means that he was ingring on the side of deliberately ba biasing his calculation to to make it slow to give it an estimate on the slow side of evolution make evolution come out slower than it might otherwise have done. But in spite of this, in spite of his being conservative and in spite of assuming that each mutation could only cause a 1% change, which is another conservative assumption, Neielson found that the evolution of the eye we've just seen would take a surprisingly short time. It would take about 250,000 generations.

[00:34:18]Well, that might sound like quite a lot of generations, but we have a rather warped perspective because after all, each one of us is only good for one generation.

[00:34:29]But our human perspective is not the one that matters. The one that matters is the geological time scale. And on the geological time scale, 250,000 generations is next to nothing. probably only about a quarter of a million years since the animals we're talking about will probably have had a generation time of about a year.

[00:34:49]>> A designer argument gets weaker when the eye is studied closely.

[00:34:54]Human eyes have a blind spot because nerves run in front of the retina and exit through the back. Octopus eyes avoid that problem because their wiring is arranged differently. That is a strange result if one perfect creator designed both. It makes much more sense through evolution. Different lineages inherited different biological limits and built around them. Literal creationism wants the eye to look planned. Biology shows history, accidents, trade-offs, and inherited structure. That is evidence, not theology.

[00:35:27]>> And a quarter of a million years is really too short for geologists to even measure. It's like trying to count seconds using the hourhand of your watch.

[00:35:42]So there really was no need for Darwin to shudder. Half an eye is better than no eye. Half an eye is better than 49% of an eye. 1% of an eye is better than no eye at all.

[00:35:57]And far from there not being enough time for the evolution of the eye. The evolution of the eye is so quick and easy that it must have happened many many times over. Eyes can evolve at the drop of a hat. And in fact, if we look around the animal kingdom, there are lots of different kinds of eyes dotted around. And each of them is different.

[00:36:18]Many of them work on completely different principles and they have evolved quite independently of each other many times over.

[00:36:26]This is the shell of a scolop, a kind of shellfish. These things are not pearls.

[00:36:32]They're eyes. But they're a very different kind of eye from anything we've seen and anything that we normally think about. Those eyes are reflector eyes. They have mirrors instead of lenses. Each one of these is a little curved mirror which works like the jodral bank telescope and forms an image in the way that a reflecting telescope does, not in the way that our eyes do.

[00:36:57]Uh this is a compound eye of an insect.

[00:36:59]Each one of these little facets is one little eye and the whole assembly together is interpreted by the brain to make one big image. Next eye. Next one.

[00:37:12]These headlights belong to a spider.

[00:37:15]Once again, this is entirely independent evolution of the eye. Is nothing to do with the other eyes that we've seen. And next, and finally, the eye of a squid.

[00:37:24]Uh this is the skin of a squid. There's its eye. The squid has a very excellent eye, very like ours, with a proper lens, proper camera principle. But you can tell by looking at the details of it, especially how it develops, that it evolved entirely independently of ours.

[00:37:39]The same principle was hit on entirely independently of ours.

[00:37:46]Once again, remember that each step is a small piece of random luck. As such, each step is not particularly impressive. In fact, it had better not be impressive because if it was, it would be a miracle and we'd no longer have a true explanation. The whole point of evolution is that it gets us up Mount Improbable without miracles.

[00:38:08]Now, I want to welcome two magnificent pinnacles of evolution on different peaks of Mount Improbable.

[00:38:20]This is an imperial eagle.

[00:38:24]And this is an eagle owl.

[00:38:35]Look at the eagle first. It's a superb machine for catching prey. Its eyes are more acute than anything that we can offer. We have no idea of acuity of vision like the eagle has. Its claws are capable of gripping in such a way that it's almost impossible once they've gripped you to get them off. They have a ratchet mechanism inside so that the bone just catches and the eagle can hardly be prized off your hand.

[00:39:05]Look at the beak. Superb instrument for tearing up its prey.

[00:39:12]The owl is sitting upon a different pinnacle of Mount Improbable.

[00:39:22]It has good eyes, but they're used in very dim light, and it relies more upon its ears.

[00:39:29]It has asymmetrical ears, which enable it to localize its prey with pinpoint accuracy in total and complete darkness.

[00:39:40]Its wings are very different from the eagle's wings, and they're shaped so that they make it fly very quietly at night. It's a stealth fighter.

[00:39:55]Both these birds, in addition to having beautiful eyes and ears, have superb wings, which brings us into our next topic. Could we see some wings, do you think? Is it possible to look at those wings?

[00:40:14]Does the owl do it as well? Lovely.

[00:40:17]Beautiful. Thank you very very much indeed.

[00:40:32]Let's see some film of wings in action.

[00:40:35]This is a hawk.

[00:40:38]And watch the way it controls the shape of the wing in gliding. Now watch it flapping.

[00:40:52]Not entirely surprisingly, creationists are also very fond of wings. And they uh once again make a similar point about what's the good of half a wing? What's the good of 3/4 of a wing? How could something like those wings have evolved from the silly little wing stubs that must have been there at the beginning of the evolution of wings? Well, let's tackle this with another little Bryson special.

[00:41:22]These are not exactly flying creatures.

[00:41:25]They live up trees and they have wings to show they're creatures. They also have little eyes to show that they're creatures.

[00:41:32]uh they live up trees and if they were to fall from the trees they would uh have been in at risk of breaking their necks.

[00:41:41]Thank you. Both of them in this case from this low height one with a little skirt and without a little skirt uh survive the the breakage at this depth.

[00:41:52]You don't need a little wing. This is a wing stub. Call it a flange or a wing stub. It's not become a wing, but we're looking at the ancestral uh stub that might eventually have evolved into a wing. When the height is sufficiently low, then nobody's going to break their neck. But if we raise the thing a bit very carefully, sometimes these animals are going to find themselves leaping from higher branches. And from higher branches, it may be that these little even pathetic little wing stubs like this might make a difference. Let's see what happens. Now right now in this case from that higher level, the strongest evidence here is not theory. It is variety. Scallops use mirror-l like eyes. Insects use compound eyes. Squids have camera style eyes that develop separately from ours. That means eyes did not appear once by magic.

[00:42:56]Vision evolved again and again because it solves real survival problems. That is devastating for creationist claims.

[00:43:04]If Christianity says one designer made life in fixed forms, biology shows branching history, repeated experiments, and different solutions across species.

[00:43:17]From that higher level, even a little wing stub like this can make a difference. And once you've got the evolution of a wing stub this long, then natural selection may favor the the wing stub getting a bit longer still because there's going to be an even higher height that you could fall from, where the difference between a wing stub that high and between a wing stub that high might make a difference. And the point is that we have a smooth gradient all the way up higher and higher heights that you could fall from to drive the lineage to drive the species towards ever longer wings.

[00:43:54]Controlled gliding has in fact evolved many times over. There are many creatures that have the equivalent of half a wing. This is a snake, a tree snake crawling along a tree. So far, it looks like an ordinary snake, but now it launches itself off.

[00:44:15]Slow motion picture.

[00:44:17]The body flattens out sideways and catches the air.

[00:44:23]It's steering itself down and it's going to land on another tree without hurting itself.

[00:44:32]This you can think of as the first step towards evolving wings. Snakes never have evolved wings, but that's one possible pathway towards evolving wings.

[00:44:41]Now, here's a squirrel, a tree squirrel, so-called flying squirrel that has flats of skin between its arms and its legs, and it glides with them.

[00:44:55]This is a very beautifully controlled glide. It's downhill all the way. It doesn't go, doesn't flap, it doesn't climb, but it lands gracefully.

[00:45:05]on a neighboring tree and is completely unheard when it does so. This is an animal again with something like 50% of a wing. And a third example is a lizard. In this case, it has skin stretched between its ribs.

[00:45:24]All these are different ways in which wings might have evolved. In no case did they properly evolve, but they show what the beginnings of wings might have looked like.

[00:45:38]So, not only can you do well if you have half a wing or a quarter of a wing, but lots of animals actually do.

[00:45:46]This is a flying lemur. Looks like the flying squirrel we just saw, but it's totally unrelated. It comes from Southeast Asia. Has nothing to do with it. I think you can easily imagine how that could eventually give rise to something like that. A flying fox, which is a bat that has proper wings. That's as good as a hawk uh that can fly and flap properly.

[00:46:07]So, we've dealt with two problems of the what is the use of a kind, the eye and the wing. Our third difficult problem, camouflage, has been thought difficult for a slightly different reason. Think back to our stick insects.

[00:46:23]And think of the fantastic detail with which they mimic sticks.

[00:46:28]A stick insect you could think of as being right at the top of Mount Improbable.

[00:46:39]So, let's put it up there. That was a lovely one. Thank you.

[00:46:42]But that has somehow to have evolved from something at the bottom.

[00:46:51]And I'm going to put on the bottom something that doesn't look remotely like a stick. This brown bug. And somehow we have to imagine that there was a gradual progression all the way up the slope all the way around the path here from something like that to something like that. Now, here's the problem.

[00:47:11]It's birds selecting insects that are propelling these animals up Mount Improbable that are propelling evolution.

[00:47:18]And in order for the birds to have propelled the last 1% from 99% like a stick to 100% like a stick, the birds must have had astonishingly good vision.

[00:47:29]They must have been very clever in order to be fooled by in order to need rather the precise detail of mimicry in order to fool them. But here's the problem.

[00:47:41]Those very same birds or relatives of them had to have been fooled down the bottom of Mount Improbable by insects that hardly look like sticks at all.

[00:47:51]Because it's the same birds propelling the insects from 1% like a stick to 2% like a stick that have to propel the insects all the way up the path 20 to 21% 99 to 100%.

[00:48:07]and say opponents of the Darwinian theory, you can't have it both ways.

[00:48:12]Either the birds are clever enough to do that job of natural selection or they're stupid enough to do that job of natural selection, but they can't be both.

[00:48:22]Well, you might like to think to yourself about possible solutions to that riddle. One thing you might think of is that it's not the same birds, that perhaps the birds have been evolving during the same time as the insects have been evolving. But I don't like that theory for reasons I haven't time to go into. I rather prefer to think that it's the same birds. They were just as clever at all stages of evolution, had just as good eyesight, but the seeing conditions were not always as good.

[00:48:48]Here we have a woodland floor which has 16 insects on it. And from where you're sitting, you can probably see some of them. And that's really the point. The seeing conditions from a distance are such that you can only see some of them.

[00:49:02]Similarly, if I look out of the corner of my eye, I can now see one or two of them, but not all of them. There are I'm going to narrow it down. Narrow down the discussion to just distance. And I'd like to call for a volunteer to help me with this. Right. Thank you.

[00:49:19]What's your name?

[00:49:21]>> Annie.

[00:49:21]>> Come here, Annie. Please. Now, where's the pointer?

[00:49:26]Thank you. Stand here. Now, tell me, can you how many insects can you see?

[00:49:32]Just point to one. We like to take the the pointer and point to it. Which which ones can you see? Can you see any?

[00:49:41]>> There.

[00:49:42]>> What do you think that is?

[00:49:43]>> Butterfly.

[00:49:43]>> That's a yellow butterfly, right? Can you all probably most of you can see that yellow butterfly. And from this distance, I guess you can probably see a blue beetle. Blue beetle. Green beetle.

[00:49:53]Perhaps that red one there. So, if you were a bird from that distance, you can see quite a lot. But now, come a bit closer, Annie.

[00:50:01]Can you see any more that you couldn't see before?

[00:50:06]>> What can you see?

[00:50:09]>> Point a black beetle and a green one there.

[00:50:14]Yes. And there there's a cockroach.

[00:50:18]I can see a cockroach there. Now, a bird from this distance could spot the cockroach, whereas a bird from that distance could spot the yellow butterfly. Now, let's come in really close.

[00:50:29]Now, can you see anything more from a bird? This distance might have a chance of seeing. What about that? What do you think that is? Come away from the stand aside there. Look at that.

[00:50:47]That's a leaf butterfly.

[00:50:51]And what about Look, Annie, look at this. What's that there? It's a leaf insect. There's its head. There's its body. There's a stick insect there.

[00:51:07]Good. Thank you very much, Annie.

[00:51:17]So, I think we've easily disposed of all three of our alleged difficulties. The eye, the wing, and camouflage. The creationist argument fails again with wings and camouflage. Small wing-like structures are useful before full flight because they help animals glide, slow a fall, or move between trees. We see that today in flying squirrels, gliding snakes, lizards, and flying lemurs.

[00:51:43]Camouflage works the same way. An insect does not need to look perfectly like a stick to survive. It only needs to be harder to spot than the next insect.

[00:51:51]Predators create pressure and the better hidden animals live longer. Religion calls these miracles. Biology shows function, pressure, and survival. That is the difference between a claim and an explanation.

[00:52:06]>> I'm going to end with a particular favorite of creationists, the notorious bombardier beetle.

[00:52:14]This is a recent headline that appeared in the Daily Telegraph. beetle that may explode the the ideas of Darwin.

[00:52:25]The Telegraph thing goes on to say, "If evolution were right, it would have exploded." The paper asks whether it offers proof of a creator.

[00:52:36]The story about the bombardier beetle is given in one creationist tract that I'm now going to read. The bombardier beetle squirts a lethal mixture of hydroquinone and hydrogen peroxide into the face of its enemy.

[00:52:50]These two chemicals when mixed together literally explode in in the face of the enemy. The chain of events that could have led to the evolution of such a complex, coordinated and subtle process is beyond biological explanation on a simple step-by-step process. The slightest alteration in the chemical balance would result immediately in a race of exploded beetles.

[00:53:18]Well, now this does sound like a bit of a challenge, a difficult case. I mustn't evade my responsibilities to take on difficult cases. Um, here we have some hydrogen peroxide and here's some hydroquinone.

[00:53:32]And this is what's going to explode violently when I've just right.

[00:53:42]Now, anybody who wants to can leave the room.

[00:53:47]>> Right, we'll start with the hydrogen peroxide.

[00:53:51]So far so good.

[00:53:54]Now, I better put it down, haven't I?

[00:54:02]What's happened?

[00:54:05]It's not even warm.

[00:54:08]bit of a damp squib.

[00:54:16]There is some truth in the story. By the way, of course, I knew nothing would happen. I mean, he was never any danger.

[00:54:22]There is some truth in the story. Uh, in fact, the hydroquinone does nothing at all. We can put that on one side. The true story is that hydrogen peroxide on its own uh does decompose to form uh oxygen and water, but it needs a catalyst under normal conditions to to do that. Um this black powder here is a catalyst. It's not the catalyst that the bombardier beetle uses. The bombardier beetle does use a catalyst and it does in fact squirt u this hot substance into the face of its enemy. But if you put a catalyst into a weak solution of hydrogen peroxide, then you're going to get a little bit of bubbling and it's a little bit warm. That might have some effect on the predator. That might slightly deter a predator and uh it would be um not particularly dangerous to the beetle. Now we got a smooth gradient, a bit more concentration of hydrogen peroxide and that's distinctly warm.

[00:55:22]that would work more effectively against a predator. And by moving gradually up the slope, gradually increasing the concentration of hydrogen peroxide, we can end up with.

[00:55:38]So there is a smooth slope all the way up to the effective deterrent against a predator.

[00:55:56]The myth that the bombardier beetle or any other feature of the natural world that has yet been described cannot be explained by slow gradual evolution is a myth that deserves to go up in smoke.

[00:56:12]Making a complicated organ in one fell swoop is equivalent to a miracle.

[00:56:18]It's equivalent to opening a bank safe combination lock in a single lucky spin of the dial. It cannot be done in one way or another. This lecture has been variations on the 747 theme. You can't make complex efficient working objects like eyes or wings in a single step. Any theory that says that life or a part of life, an organ, an animal, complexity or perfection came into being in a single step starting from nothing has got to be wrong.

[00:56:55]Evolution is the one idea that has nothing to fear from the 747 argument because evolution is the one idea that does not suggest that complex perfection came into being in a single step.

[00:57:11]It is the theory of miraculous creation that is really blown out of the water by the 747 argument. Because it is miraculous creation that is equivalent to cracking the safe in a single step, equivalent to blowing together a 747 in a junkyard.

[00:57:29]Evolution escapes the taint of miracle, escapes the taint of impossibly long odds by the simple yet hugely effective trick of smearing out the luck, smearing it out over the vastness of geological time.

[00:57:46]>> The bombarder beetle is another creationist scare tactic that sounds impressive until chemistry enters the room. The claim is that the beetle should explode if evolution is true.

[00:57:56]That is false. The chemicals do not automatically explode together. The reaction depends on concentration, enzymes, and controlled release. Even a weak defensive spray can bother a predator, so stronger versions can be favored over time. This is where religion loses the argument. It calls a gap in knowledge God, then science fills the gap. The beetle does not defeat evolution. It exposes how weak creationist claims are. So, what do you think? Does the eye, the wing, and the bombarder beetle point to design, or do they show evolution doing exactly what science predicts? Comment your answer below and don't forget to like and subscribe.