#923 - Matt Ridley - Why Evolution Favours Beauty Over Survival

Speaker 1 What was Darwin's strangest idea?

Speaker 2 Sexual selection by mate choice is the idea that Darwin had alongside natural selection, and which he maintained was a very different process.

Speaker 2 Almost nobody agreed with him in his lifetime. It was a failure in the sense that

Speaker 2 he couldn't persuade people that this was an important thing.

Speaker 2 And when people did agree with him, they thought, well, yeah, but it's just a small niche thing in the corner of biology. And I don't think that's right.

Speaker 2 I think he was onto something that actually, actually, when mates are selective, which they are in many species, it drives a huge amount of evolution in the other sex.

Speaker 2 And it's a very different process from natural selection. I call it the fun version of evolution because it produces

Speaker 2 loud songs and things like that.

Speaker 2 It's less utilitarian.

Speaker 2 Yeah.

Speaker 1 What was the reaction when Darwin first proposed sexual selection?

Speaker 2 Well, he mentioned the idea in The Origin of Species very briefly. And he said, I think that

Speaker 2 he had a friend called Sir John Seabright, who'd been breeding rather beautiful bantam,

Speaker 2 new varieties of bantams. And he said, if a man can produce a beautiful bantam in a short time, then why can't a female produce a beautiful male in over a thousand generations?

Speaker 2 And he was ridiculed for it. And by the time of the fourth edition of The Origin of Species, he felt it necessary to put in a sentence saying,

Speaker 2 yeah, look, they are beautiful, these male birds, to us, but that doesn't mean they were put on earth to please us. They could have been put on earth to please females.

Speaker 2 And this made things worse because everyone else said, I'm sorry, are you suggesting that female birds are capable of aesthetic discrimination? Give me a break.

Speaker 2 And Wallace, in particular, deserted him on this topic. So did Thomas Henry Huxley, Herbert Spencer, all his normal defenders were not prepared to defend this idea.

Speaker 2 Partly, these crusty old Victorians were a bit uncomfortable with the idea of women having sexual agency at all, of course,

Speaker 2 let alone lust.

Speaker 2 So, you know, one has to take into account that.

Speaker 2 But

Speaker 2 I then,

Speaker 2 I'm very fond of a person who features in my book called Edmund Salouse, who was a um

Speaker 2 an amateur naturalist who watched the same species as me, the black grouse, as well as a number of other species. And he said, you know, Darwin was right.

Speaker 2 The evidence speaks trumpet-tongued in his favor, which is such a nice phrase, I think.

Speaker 2 Because

Speaker 2 it's clear when you watch some of these birds that the females are being very selective and are in charge of whether or not mating happens.

Speaker 1 Yeah, I can imagine that Victorian England wasn't superbly keen on the idea of flipping the gender hierarchy upside down and saying, well, maybe, you know, maybe the males were shaped by female preferences.

Speaker 1 And that also sort of has in it a sense of uh um almost sort of promiscuity i in a way, a degree of female sexual agency, which again, Victorian England, uh, probably not superbly uh popular.

Speaker 2 Yeah, and we we don't need to be all that smug about Victorian because we too tend to say, Well, hang on, isn't female beauty to males more important than male beauty to females in our species?

Speaker 2 And it might well be the case. I mean, that's true in some bird species, but actually, in our species, both sexes are highly selective when they choose long-term partners.

Speaker 2 And so there's going to be, you know,

Speaker 2 different criteria, but similarly choosing similar choosiness in both sexes.

Speaker 2 But yeah, no, people find it instinctively odd that women should be choosing that females should be choosing males on the basis of appearance.

Speaker 1 What is the fundamental mystery when it comes to sexual selection?

Speaker 2 The fundamental mystery is

Speaker 2 why so many species

Speaker 2 indulge in growing and displaying features that hinder their own survival, take a lot of energy, and can be amazingly flamboyant.

Speaker 2 You know, if you look at some of the birds of paradise that do a sort of shape-shifting display where they disappear into a sort of black hole and project an iridescent, smiley face on it.

Speaker 2 You know, it's

Speaker 2 what on earth is going on? It's such an eccentric outcome to come from evolutionary biology that

Speaker 2 it still doesn't.

Speaker 2 Where's the Rhymal reason?

Speaker 2 is another way of putting it. And actually, I see evolutionary biologists' arguments over the last 150 years as being a series of last-ditch attempts to put rhyme or reason back into this process.

Speaker 2 And there might not be rhyme or reason.

Speaker 2 It might be just be extravagant for your own sake because females are going to go for the most extravagant thing you can do.

Speaker 2 And I'll explain why I think that works as a technique.

Speaker 1 Yeah,

Speaker 1 I can imagine,

Speaker 1 I can see, especially in a...

Speaker 1 a civilization which still has the sort of conceptual inertia of intelligent design, of beauty being sort of divinely bestowed from above, that you observe these birds doing crazy dances and making themselves into smiley faces and hopping around and pecking and doing all of this stuff and thinking, well, how lovely that God has made these birds do this dance for our benefit.

Speaker 1 This is beauty incarnate. I get to observe and enjoy.
You go,

Speaker 2 maybe he wasn't for you.

Speaker 2 Right. And

Speaker 2 the bird that Wallace and Darwin ended up arguing about most in 1868 when their dispute over this came to a head was a bird called the Argus pheasant, which is a sort of peacock-sized bird in the jungles of Southeast Asia, newly discovered at the time, which has enormous wings, very, very long wing feathers.

Speaker 2 And these wing feathers have a series of objects depicted on them that are clearly intended to be three-dimensional optical illusions.

Speaker 2 In other words, they look like little spheres because they've got highlights at the top and shading at the bottom.

Speaker 2 So somebody's gone to great trouble to make these things look as if they're actually three-dimensional. You know, they're sticking out of the feather like a sort of pebble or a jewel.

Speaker 2 And

Speaker 2 genuinely, Darwin's critics, including a guy called Wood, who was

Speaker 2 doing the pictures actually for his book, said, look, I'm sorry.

Speaker 2 for this to be created by females, female birds, you've then got to posit that females have an aesthetic sense.

Speaker 2 But the idea that a bird with a brain the size of a walnut is capable of appreciating and enjoying three-dimensional optical illusions is for the birds. I mean, he didn't use that phrase, but

Speaker 2 that was the implication of what he said.

Speaker 2 So

Speaker 2 there's real...

Speaker 2 You know, you know,

Speaker 2 people like Sir Joshua Reynolds have been writing books books about aesthetics at this stage and saying you need to have been to Oxford to really understand aesthetics.

Speaker 2 But sorry, can I go back to one thing you said, which

Speaker 2 intrigues me, and that's

Speaker 2 the idea of intelligent design. Because in some ways,

Speaker 2 Darwin is flirting with something that looks a bit more like intelligent design here. And it's been pointed out by Evelyn Richards and others, who's a historian of this period, that

Speaker 2 his interest in natural selection almost seems to dry up after the origin of species. He doesn't spend a lot of time talking about it.

Speaker 2 His next books are about things like the domestication of animals. Well, that's not natural selection, that's artificial selection.
And then sexual selection, which again is females driving

Speaker 2 the

Speaker 2 selective process.

Speaker 2 And Wallace, his friend and rival, reacts against this in exactly the way that you might, where he sort of says, Look, I'm now more Catholic than the Pope.

Speaker 2 I really believe in this bottom-up natural selection, survival of the fittest thing. And I think bird beauty is just for some reason something that helps the species survive or the individual survive.

Speaker 2 And it's a part of natural selection. And I don't like the way Darwin is flirting with conscious beings, which female birds are,

Speaker 2 choosing what males should look like. Now, Darwin isn't going that far.
He's not, you know, he's not literally saying that

Speaker 2 females are sitting down and planning what they want peacocks to look like.

Speaker 2 But

Speaker 2 there's a little bit of,

Speaker 2 you know,

Speaker 2 he's prepared to accept

Speaker 2 that

Speaker 2 evolution can be directed in a way that looks a little dangerous to people like Wallace.

Speaker 1 Isn't it interesting that Darwin, someone whose proposals were recently heretical to the previous dominant ideology, inside of his own new ideology becomes a heretic?

Speaker 1 You know what I mean? That's a lovely way of putting it.

Speaker 2 Thank you. Yes.

Speaker 2 Absolutely. And

Speaker 2 there's a plaintive quotation from him at one of his last meetings at the Linnaean Society before he died, where he says, I still think I'm right. I know all you guys tell me I'm wrong.

Speaker 1 By this point,

Speaker 1 he's sort of pleading with them.

Speaker 2 Yes,

Speaker 1 begging as he's being. I mean, again, look,

Speaker 1 maybe he doesn't have the spear in the side and the crown of thorns on the head, but it does feel a little bit like a guy who's being like prostrated a little bit.

Speaker 1 He's sort of begging for a bit of like, guys,

Speaker 1 please, like, it's ultimately this is going to hurt you more than it's going to hurt me on judgment day, you know, like he does have this like Messiah thing going on. Although, as far as I've read

Speaker 1 Robert Wright's book was the first one, Moral Animals, what got me into evolutionary psychology.

Speaker 2 Again, for a wonderful book.

Speaker 2 I mean, that book is 30 years old now.

Speaker 1 More than 30 years old. It's like 92 or something, it came out.
And for anyone that wants a good kind of

Speaker 1 half-biographical look at Darwin's life with framing of evolutionary psychology. There's some stuff in there that's a little outdated.

Speaker 1 Obviously, it's three decades of a relatively new field, so some stuff's moved on, but it's so great. But in that,

Speaker 1 Darwin seemed to be pretty sort of racked by self-doubt, uncertainty. He had a little bit of a disposition toward low moods sometimes.
And

Speaker 1 I imagine

Speaker 1 he doesn't have the he doesn't get mad, he gets sad, and he doesn't have the big sort of fuck you energy that a renegade, rebellious, anarchist thinker would have.

Speaker 1 So I think he's actually kind of an unlikely

Speaker 1 individual to go so hard against the dominant sort of mainstream hegemon that was whatever came before him.

Speaker 1 And I do wonder what would have happened, how much further his work could have got if

Speaker 1 he didn't have to get over not only himself, but then the additional pressure of everybody else saying he was wrong and then his own self-doubt being reinforced by what people were saying from outside of him.

Speaker 1 It must have been really tough for him to navigate because he didn't have, I think I'm right in saying this, by the time that he died, he still didn't have a fully perfect explanation of the peacock's tail.

Speaker 1 It was this sort of

Speaker 1 it's kind of there, and I think I've got this inclination, but I don't have something that's concrete.

Speaker 1 And then, if all of your peers are saying, yeah, mate, you, I mean, you hit the lottery once with that thing,

Speaker 1 but you don't get to run it, you can't wheel it up and run it back another time. Um, it's justn't going to work.

Speaker 2 Yeah, that's all true. I mean,

Speaker 2 in he is a cautious, conservative establishment figure. He's, you know, he's wealthy and mixes in upper-middle-class circles and,

Speaker 2 you know, he's not a boat rocker in the sense. I mean, Wallace is a socialist and a feminist and all sorts of, and, you know, a man of humble background and things like that.
So in that sense,

Speaker 2 Darwin is an unlikely revolutionary. But in another sense, I don't think you're right to say that the self-doubt held him back.

Speaker 2 Once he'd committed to writing The Origin of Species, which took a big leap and took 20 years of angst, as you say, before he did, once he did, he very rarely gave an inch. Well, no, that's not true.

Speaker 2 He compromised. Actually, the later editions of The Origin of Species are much less convincing than the early ones because he is trying to compromise with his critics.

Speaker 2 And he's obviously, you know, feeling the pain of some of the criticisms.

Speaker 2 But

Speaker 2 he then plows on, finding all these stories about animals and plants and details that can buttress his ideas. And

Speaker 2 there's no sense in which

Speaker 2 he sort of wants a quiet life.

Speaker 2 Well, he does. He doesn't want to get involved in the controversies himself, but he wants to keep pushing the ideas out there.
So he's a magnificent person.

Speaker 2 But Robert Wright was the one who pointed out, and I'd never thought this before until I read Robert's Robert's point on it,

Speaker 2 that

Speaker 2 the

Speaker 2 way in which Wallace's letter from Papua New Guinea, or from New Guinea, was handled

Speaker 2 was quite cunning on Darwin's part.

Speaker 2 And that quite selfish, actually.

Speaker 2 We tend to think of him as being magnificently generous and saying, look, this chap has scooped me,

Speaker 2 but why don't we both present our ideas at the Linnaean Society together?

Speaker 2 Yeah, but when it came to it, Wallace was off in New Guinea, didn't know this was going on, they didn't have time to tell him.

Speaker 2 Lyle says, Look, look,

Speaker 2 you poor chap, Darwin, don't get too head-ump about it. We'll have a meeting and we'll present your paper first and then Wallace's, and you'll get the credit.

Speaker 2 And so, in a sense, Wallace does get shafted by this process.

Speaker 2 And

Speaker 2 Darwin, for all his politeness, can be aware of the...

Speaker 1 He's got a ruthless streak in him.

Speaker 2 He's got a ruthless streak and he wants his priority

Speaker 2 on this topic.

Speaker 2 But back to sexual selection,

Speaker 2 Wallace wins the argument in their lifetimes

Speaker 2 and continues to really, in many ways, up till today, actually. The versions of Wallace's theory are still pretty popular.
We can come back to the details of that if you like.

Speaker 2 And some of the things Darwin says in his dispute with Wallace are quite stupid, actually.

Speaker 2 For example, Wallace said, Look, female birds are mottled brown because they want protection on the nest.

Speaker 2 They don't use the word camouflage because it hasn't been coined yet, but that's what they mean.

Speaker 2 And

Speaker 2 the reason I know that is because female birds that breed in holes are often quite brightly coloured, things like parrots or kingfishers or woodpeckers.

Speaker 2 And

Speaker 2 Darwin says, No, no, no, no, I don't believe that females are camouflaged.

Speaker 2 And you think, why not? And it's because

Speaker 2 he's desperate not to give an inch on the idea that

Speaker 2 sexual selection is driving bird colour.

Speaker 1 Why are birds so useful to use for this study? What is it about birds? Why is it not

Speaker 1 dogs? Why is it not cows? Why are we not using sheep for this study?

Speaker 2 Birds are a bit more like us than many mammals. They like song, they like colour, they like visual things.

Speaker 2 We've got pretty good colour vision for mammals.

Speaker 2 Most mammals have only got two colour channels. We've got three, as have other primates.

Speaker 2 So we see a much more colorful world.

Speaker 2 rather like the world the birds see, not nearly as colourful as they see. They've got at least four channels.
They've got ultraviolet vision, all sorts of things.

Speaker 2 So to some extent, we can sort of empathize with birds.

Speaker 2 But, in terms of the study of sexual selection, birds really do stand out because there has been an explosion of dramatic shapes, crests, plumes, colours, displays, dances, and songs in the birds that dwarfs other species.

Speaker 2 So, if you just take song, for example, I was out this morning when the sun came up, and the bird song was fantastic. It's springtime.

Speaker 2 There was no mammal noise at all. Maybe I heard a sheep at some point.

Speaker 2 Maybe a dog barked in the distance, but that was it. You know, if we didn't have birds, think how silent it would be.

Speaker 2 And song is quite a useful thing to study, actually, if you want to understand what's going on here.

Speaker 2 And so,

Speaker 2 without

Speaker 2 birds, well, also,

Speaker 2 you know, bird watching gets a lot of human beings into natural history and then into biological sciences.

Speaker 2 Me, I was a bird watcher before I ever thought of being a scientist, and that's true of a lot of people. Jim Watson, who discovered the

Speaker 2 co-discovered the structure of DNA,

Speaker 2 he was a bird watcher as a teenager, and that's what got him interested in biology, etc.

Speaker 2 So

Speaker 2 I think

Speaker 2 now you could say butterflies, dragonflies, lots of sexual ornamented colours, fish, lots of bright colours, but they're not as easy to study.

Speaker 2 They're either too smaller or they're harder to observe or they're underwater or something. Birds are the obvious ones to go for.
Mammals, mammals are brown.

Speaker 2 with very few exceptions. I mean, there's a black one and a grey one and a few monkeys have colourful faces.
But apart from that, they're really grim to look at.

Speaker 2 And the noises they make are terrible, really.

Speaker 2 And also, they do a lot more sexual coercion than birds.

Speaker 2 There's another way in which we're similar to birds, and that is forming pair bonds to bring up offspring. Birds do a lot of that.

Speaker 2 Most birds, black grouse are an exception, peacocks are an exception, but most birds, the male and female, collaborate to rear the young.

Speaker 2 And again, we empathize with that. In an awful lot of mammals, all the work is done by the mother,

Speaker 2 both gestating and lactating, obviously, and nurturing the offspring. So there's a sense in which we are honorary birds.

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Speaker 1 Okay, okay.

Speaker 1 So getting into the meat of it, why do females choose certain males based on beauty and performance rather than obvious survival traits?

Speaker 2 Right. So why not just choose a strong male who will give you strong children?

Speaker 2 And the answer is that you've got a

Speaker 2 there's a seduction going on. It's a charm.
It's a persuasion. It's not a coercion.
That's the first point.

Speaker 2 The second point is, yes, but why let yourself be charmed by a flamboyant tail or bright colours or whatever?

Speaker 2 And the argument that Wallace raised and that has reverberated since through the topic is that it's a proxy. for fitness of some kind.

Speaker 2 It's telling you if you can grow that peacock's tail and keep it in good nick and display it frequently, then you must be quite healthy.

Speaker 2 You must have good disease resistance genes or something like that.

Speaker 2 And that's the kind of version of sexual selection we always hear from natural history programs and that is generally pursued by most biologists. And it's probably not wrong.

Speaker 2 But there's another thing going on that it's, I think, usually more important, particularly when you get these exaggerated

Speaker 2 flamboyant

Speaker 2 plumages.

Speaker 2 And that is the idea that

Speaker 2 Ronald Fisher first thought of in 1930 and was later mathematically proved by

Speaker 2 Russell Landy and Mark Kirkpatrick in 1980. And that is that

Speaker 2 the fitness the females are after may not be just whether their offspring survive, but whether their offspring seduce.

Speaker 2 That the thing that really matters to them may be having offspring that can

Speaker 2 persuade members of the opposite sex to mate,

Speaker 2 particularly male offspring.

Speaker 2 And that it's no use

Speaker 2 choosing an ugly

Speaker 2 male partner that is particularly strong and disease-resistant so that you can have strong and disease-resistant sons

Speaker 2 if those sons can't persuade other females to mate with them because they haven't got flamboyant tails, otherwise known as the sexy sun hypothesis, the sexy sun hypothesis, and that's a sort of runaway effect.

Speaker 2 Seduction of the hottest versus survival of the fittest is another way I put it. I didn't think of that till after I'd finished the book, but what a shame.
That was good. That's good.

Speaker 1 Okay, so we have this sort of Fisherian runaway selection thing going on that

Speaker 1 traits that are sexually attractive are selected. Over time, that causes sons to become sexier, but eventually you end up with a risk and a trade-off for the males.

Speaker 1 Even before we get on to risks and trade-offs, why is it that there is such a thing as sexiness that isn't just utility of survivalness? Why is it not that maximized survivalness is sexiness?

Speaker 1 Why is there this other pathway,

Speaker 1 this other attribute? Right.

Speaker 2 Well, the answer to that, I think the clue to it,

Speaker 2 and I can't prove this, and this is the problem with this version of sexual selection theory, it's very hard to devise experiments that prove it. I will mention one in a minute, but the answer,

Speaker 2 I think,

Speaker 2 is that the smallest

Speaker 2 bias in the females in a random direction will get exaggerated. And it doesn't really matter which direction it's in, it will run away, and you can't stop it.

Speaker 2 And so, the clue is the fact that you get such extraordinary diversity of sexually selected ornaments in birds and other animals.

Speaker 2 In other words, there is no pattern, you know, there's no general practice that they tend to have eyes.

Speaker 2 Right, it's not

Speaker 1 always the biggest tails, it's not always the brightest.

Speaker 2 It's not always the tails, it's not always the wings, it's not always the crests, it's not always the breast, it's not always the back, it's not always red, it's not always yellow.

Speaker 2 Do you see what what I mean?

Speaker 2 And once you start looking at the extraordinary diversity of ways in which sexual selection has gone mad in the birds of paradise, in the pheasants, in the mannequins, in species like that,

Speaker 2 you know, why do puffins have red and blue stripes on their beak? You know, that's a sort of completely different way of doing things. There's a bird called the dragopan, which

Speaker 2 pops out from behind a log when he's trying to seduce a female and lowers from his throat an electric blue apron with red patterns on it

Speaker 2 of skin.

Speaker 2 Why?

Speaker 2 So it's the very arbitrary nature of the features that I think argues for this process. Now, you can still say, yeah, but why, you know, why would it matter?

Speaker 2 And of course, probably what's going on is that to start with, being a bit brighter than another male does mean your immune system's in better order or you haven't been infected with malaria or something like that.

Speaker 2 So the probably, you know,

Speaker 2 at the end of the book, I say, hang on, we're constantly trying to choose between these two theories, fitness and hotness, if you like, and

Speaker 2 we shouldn't have to. They're obviously both going to end up assisting each other.

Speaker 1 Well, if you assume that the reason that you have fitness is to survive in order to be able to reproduce and hotness allows you to reproduce more quickly,

Speaker 1 they end up netting out at the same outcome, even if they sort of get there in different

Speaker 1 paths.

Speaker 2 Yes, but it might be worth mentioning that

Speaker 2 what I think is the best experiment I describe in my book,

Speaker 2 it doesn't feature birds, unfortunately, it features a small insect. And it was done by Andrew Balmford and one of his students on a sort of Brazilian fly.

Speaker 2 And what he did was he

Speaker 2 took the

Speaker 2 he he allowed them to mate

Speaker 2 and in in the laboratory this is and the

Speaker 2 she actually it was she who did the work and I'm trying to remember her name but but Andrew's student and

Speaker 2 he he chose he bred from the

Speaker 2 he he he took the unsuccessful males and put them on one side and the successful males and he bred a lineage from one and he bred a lineage from the other.

Speaker 2 So he's now got the failures and the successes fathering the next generation. And he does that for several generations.

Speaker 2 And then he says, what's the difference between these

Speaker 2 flies at the end of several generations? Are they less able to survive because they've been bred from the failures? And the answer is no.

Speaker 2 Are they less able to persuade other flies to mate with them? Yes.

Speaker 2 So that's quite a nice, that's the best experiment for teasing out these two hypotheses that I've come across.

Speaker 1 That's really cool to understand that there is one dial for fitness and one dial for hotness, and they're maybe interrelated upstream before them. There is something that causes them both to happen.

Speaker 1 And maybe they do, on average, tend to happen sort of synchronously, that fitter tend to be hotter. I would also imagine that that's the case.

Speaker 1 But that they are distinct and they are interpreted in different ways. So

Speaker 1 that's cool. So just to kind of round out the fisherian runaway thing,

Speaker 2 any

Speaker 1 minor advantage in terms of sexual selection trait display that a male has,

Speaker 1 if it's even, you know,

Speaker 1 51, 49, over time, that will be selected for sufficiently that it continues to get more and it continues to get brighter and it continues to get more elaborate.

Speaker 1 And that's where you end up with after a few million years of evolution, you just end up with these sort of very, very extravagant displays.

Speaker 2 Yes. Although if the runaway process is as accelerating as Fisher thought, then it might not be a million years.

Speaker 2 It might be one of these things that happens really, very quickly in a few thousand years.

Speaker 2 And

Speaker 2 you know, the peacock might have gone from having a short tail to having a huge tail in the sort of blink of an evolutionary eye.

Speaker 2 And one of the ideas I toy with in the book is:

Speaker 2 can we catch a species

Speaker 2 in the moment when it suddenly starts having a runaway selection

Speaker 2 and come back in a thousand years and see what's happened?

Speaker 1 You need to, I don't know, I feel like you need to sow the seeds with

Speaker 1 girly daytime magazines, you know, that have got the new trend. What to look for in this summer's new boyfriend or whatever.
And that's how you sort of inject it socially. And from there,

Speaker 1 the runaway begins.

Speaker 2 Well, this is why I went

Speaker 2 and sat for two nights running on top of a mountain in Norway,

Speaker 2 not allowed out of my little canvas blind from 8 p.m. to 8 a.m.

Speaker 2 watching a bird that displays at midnight through the middle of the night called the Great Snipe.

Speaker 2 Of course, it's not dark in Norway at that time of the year.

Speaker 2 And

Speaker 2 the Great Snipe looks like any other snipe. There are 17 species of snipe on the planet, and they are all sort of really well camouflaged in marsh vegetation, including this one.

Speaker 2 It doesn't look much different.

Speaker 2 But this one does this lecking. Males gather together and competitively display.

Speaker 2 And at the height of its display, it flashes the white feathers in its tail.

Speaker 2 And it's like turning on a light. It's a very bright little flash, very brief.
But the tail feathers are not very exaggerated, and they're not much whiter in the male than the female, a little bit.

Speaker 2 And if you tip X some of the males' tails, so they're

Speaker 2 young people, don't know what tipx is, but you know, if you put white paint on some of the males' tails,

Speaker 2 you can improve their mating success, according to some Scandinavian biologists who are very ingenious.

Speaker 1 Oh,

Speaker 1 it's like a snipe aesthetician giving them some beauty, beautification, augmenting. So it's a boob job.
It's a boob job for snipes. Exactly.

Speaker 2 Exactly.

Speaker 2 And so, but

Speaker 2 my point is,

Speaker 2 male snipe and female snipe look almost identical. In fact, you can't really tell the difference.
And the tail is a bit different, but you can't see it very well most of the time.

Speaker 2 Maybe this is a species that's only just started having highly skewed sexual mating success, so that one male gets to mate with ten females, which is roughly what happens.

Speaker 2 And that it hasn't had time for the tail to get huge and white and dramatic, and that might be about to happen.

Speaker 2 The conventional explanation for the great snipe is that it it's

Speaker 2 it it because it's often displaying in very poor light, there's no point in being brightly colored.

Speaker 2 Um and a lot of the display involves making clicking noises, and maybe it's an auditory leck rather than a visual leck. But other birds make noises on the leck, too.

Speaker 2 So I kind of like my idea best that this is a species that's only just begun to leck.

Speaker 2 And there's another bird called a buff-breasted sandpiper, which sort of lecks, but sort of doesn't. And I'd like to watch that species for a thousand years and see what happens.

Speaker 2 What's the leck paradox?

Speaker 2 The leck paradox is that the black grouse, which leck, live next door to the red grouse, which don't. They pair up.

Speaker 2 So one male, one female, and they both bring up the kids.

Speaker 2 Therefore,

Speaker 2 because the one male gets to mate with 10 to 20 females in the black grouse,

Speaker 2 but the other 19 or 9 or 19 males on his leck don't get to mate at all that year,

Speaker 2 the bird will have less genetic diversity in its population than the red grouse.

Speaker 2 It will

Speaker 2 be more genetically monotonous. It will be more inbred.

Speaker 2 Not to the stage where it's a sort of health problem because the males usually only get one year at the top and the females disperse. And so, you know,

Speaker 2 the species is fine in that sense.

Speaker 2 But

Speaker 2 it must be the case that there is less genetic diversity in a lecking species like the black grouse than a monogamous species like the red grouse in which case there's less point in being choosy

Speaker 2 because the genes are going to be more similar i mean when you go onto a leck you're bound to be looking at some half-brothers because they tend to recruit to a leck near where they were born and they if they were born in the same year then the chances are they had the same father even though they might have had different mothers.

Speaker 2 So if they're half-brothers and they look the same, and by the way, they do look very similar to us, then what's the point of being so choosy? The species that are most choosy about

Speaker 2 making sure you get the very, very best male and not settling for second best,

Speaker 2 which the red grass do all the time. They say, look, I just want a bloke who's going to look after the kids.
I don't care what he looks like.

Speaker 2 I'm anthropomorphizing, but you get the point.

Speaker 2 The species that are most most choosy have least reason to be choosy. That is the Leck paradox.

Speaker 2 And I think the Fisher theory shows you a way out of it.

Speaker 2 It doesn't matter how little variation there is. You've still got to follow the fashion.
But it not really. I mean, I'm struggling with it too.
So it is a paradox, and it's an intriguing one.

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Speaker 1 That's join.whoop.com slash modern wisdom. Right.
So

Speaker 1 birds that have these

Speaker 1 speed dating, which is kind of bird speed dating, is what sort of

Speaker 1 lecking is in a way.

Speaker 2 Yeah, but speed dating where they all end up mating with the same male, remotely. Yeah, yeah.
Okay, good. Non-monogamous.
It's not happening to you and me.

Speaker 1 Non-monogamous speed dating for birds.

Speaker 1 In those situations, you have a lot of the reproductive rewards accruing to a few at the top.

Speaker 1 You also have to assume that that would mean

Speaker 2 the more

Speaker 1 sexually selective

Speaker 1 the women are being, the more that they're skewing toward that single male or small number of males at the top, there's going to be less of a chance of

Speaker 1 survival for that next generation that comes along just due to some of the inevitable reduced

Speaker 1 genetic diversity. So you think, okay,

Speaker 1 these two things kind of do come into conflict a little bit with each other. The hotness and the fitness can actually start to, it feels like they can fight against each other.

Speaker 2 Yes, well, the conspicuous plumage for a start is a threat to survival.

Speaker 2 The dancing and fighting that you do for months on end is a threat to your survival. So, yeah, males are putting themselves at risk to present themselves.
But one way of looking at it is that

Speaker 2 the black grouse and the red grouse, the males are putting in an awful lot of effort in both species.

Speaker 2 But

Speaker 2 the red grouse, the effort is going into

Speaker 2 escorting the female, defending the territory, escorting the chicks, helping the chicks, sheltering the chicks,

Speaker 2 being vigilant over the family, things like that. Whereas the black grouse, the effort is going into endless displays, fights, competitive dances, and so on.
So you end up

Speaker 2 deciding which way to push your effort. And when you push all your male effort into display,

Speaker 2 you are wasting it as far as the lineage is concerned, as far as the chicks are concerned. In the sense that,

Speaker 2 you know, so if I go out in June,

Speaker 2 in the Pennines, I can find a pair of red grouse in which the male is standing up looking around and the female is down in the heather with the chicks and and he's got his eyes out and if he sees a hawk coming he gives an alarm call and they all hide.

Speaker 2 He's very valuable in that sense. If I find a black grouse with chicks, there's no sign of the male.
He's miles away. He's had his two seconds of fun two months ago or whatever.

Speaker 2 The female is entirely on her own and having a one parent looking after the offspring as opposed to two is bound to be a disadvantage.

Speaker 2 And sure enough, blackgrouse seem to have have lower chick survival through that period of when chicks are small. And indeed, they have smaller broods, actually.

Speaker 2 So the species as a whole is not going to do as well.

Speaker 2 And that's a rather intriguing thought, I think, that sometimes these sexual selection arms races end up making a species more likely to go extinct.

Speaker 1 That's fascinating.

Speaker 1 Sexual selection could actually be a maladaptive force sort of that pushes species toward an unsustainable extreme.

Speaker 2 I mean, this idea has been around for a long time, and there was a sort of rather cartoonish version of it that was in vogue for a while. Do you remember the ancient Irish elk,

Speaker 2 this species that went extinct at the end of the ice age, which was an enormous deer bigger than a moose and with huge antlers, much bigger than a moose's antlers, but similar in shape to a moose's atlas.

Speaker 2 And

Speaker 2 how on earth these poor deer managed to carry these vast antlers around

Speaker 2 is a sort of bit of a mystery.

Speaker 2 And what were they for? Were they for fighting or were they for displaying?

Speaker 2 And actually, there's some quite good evidence that they might have been more about display than fighting, based on how good they would have been

Speaker 2 as weapons, if you like.

Speaker 2 But

Speaker 2 the question of why that species went extinct used to be dominated by the theory that the antlers got too big and the deer couldn't fit

Speaker 2 between the trees when you're and my ancestor was running after them with a spear. And so they caught them.

Speaker 2 Now, nobody thinks that's why it went extinct. It was a large animal.
Our ancestors were very good at wiping out large animals, which were slow breeding.

Speaker 2 and easy to find.

Speaker 2 You know, they wiped out mammoths and woolly rhinoceroses and stepped bison and things as well.

Speaker 2 So at the end of the ice age, it was doomed because it got predated by human beings, not because

Speaker 2 or because climate changed or something, not because

Speaker 2 the antlers were too big. And besides, if you look in some of the best bogs in Ireland that have lots of these animals in them where they got stuck in the mud,

Speaker 2 there was higher mortality among young than old deer, as you'd expect in any species.

Speaker 2 So that,

Speaker 2 you know,

Speaker 2 the

Speaker 2 you can take these arguments about sexual selection being a handicap

Speaker 2 a little too far if you're trying to use them to explain the extinction of a species, but but maybe it does play some role.

Speaker 1 How extreme can these traits become then?

Speaker 2 Well,

Speaker 2 if you

Speaker 2 there's a little bird called the club-winged mannequin,

Speaker 2 which

Speaker 2 has a display in which it makes a sort of

Speaker 2 resonant twanging noise with its wings which carries a long way through the Ecuadorian cloud forest where it lives

Speaker 2 and

Speaker 2 in order to make this noise the bird has had to redesign not just the feathers of its wings which are

Speaker 2 contorted in a sort of strange way, but the wing bones themselves. Wing bones are generally the same in all birds.

Speaker 2 I mean, obviously, there's a scale difference, big birds and small birds, but the shape of a wing bone is generally pretty well defined as being, you know, the best strength to weight ratio and things like that.

Speaker 2 Not in this species. It's got a sort of weird, heavy, club-shaped wing bone in its body, I mean, in its wing,

Speaker 2 which is there purely to enable it to make a twanging noise in the springtime or the breeding season. They don't have spring on on the equator.

Speaker 2 And

Speaker 2 Richard Prum has written about this in his book, The Evolution of Beauty.

Speaker 2 And

Speaker 2 it's quite a good example of just the length. I mean, this must make it harder to fly for a start.
The lengths to which sexual selection can go. A peacock's tail,

Speaker 2 There's a bird called the Bulwers Pheasant, which lives in Borneo, where the male, when he displays, disappears into an enormous sort of white disc,

Speaker 2 which actually comes from his tail.

Speaker 2 And his head is then hidden by fleshy,

Speaker 2 inflated blue tubes that stretch before and after the head.

Speaker 2 So he looks like a sort of plate with a blue knife on it.

Speaker 2 That's not a very good description, but do you see what i mean and and and you know you get to think poor creature you know what have the females done to this species to make it

Speaker 2 um uh to to submit it to these ordeals but that gets to another point which i'm intrigued by which is that sexual selection can be possibly a more creative force than natural selection because instead of just saying in a utilitarian way i just want to enable you to survive it says let's try something really wacky and see what we end up with and richard prum has this theory he's the guy who worked out what color the feathers were on dinosaurs by the way and he has this theory that that feathers were invented for display before they were ever used for flight and that we wouldn't have had flight if we hadn't had sexual display wow

Speaker 1 that is cool yeah i suppose if you're just rolling the dice in so many ways it's like hey they might be attracted to this try it on you know here's a new outfit, here's a new fashion, have a crack.

Speaker 1 Exactly.

Speaker 2 Yeah.

Speaker 2 And I haven't mentioned the bower birds, but I've got to get them in at some point.

Speaker 2 Australia and New Zealand, sorry, Australia and New Guinea, where bower birds live, these are birds that have basically invented art.

Speaker 2 They build

Speaker 2 complicated structures, not to nest in, but to seduce females in. It's the males that build them.
And they decorate them with colourful objects arranged

Speaker 2 in ways to enhance perspective and ways to look decorative and sorted by colour and all sorts of things.

Speaker 2 And I watched a great bower bird at his bower trying to seduce a female with a red chili pepper,

Speaker 2 which he was displaying to her

Speaker 2 on the edge of a cemetery in Queensland in Australia.

Speaker 2 But his main

Speaker 2 art installation was a huge patch of grey and white objects, which snails, shells, and

Speaker 2 bones and things like that, but also bits of plastic and bottle tops and bits of broken glass, etc., because we were in the edge of a town.

Speaker 2 And this art installation included not only a plastic hand grenade, but a tiara, a toy tiara. I think it was a toy.
Maybe it was a real diamond tiara.

Speaker 1 What about

Speaker 1 seemingly tiny traits? Very sort of minuscule things that for us to look at, we wouldn't realize that it was actually a different, but that that is something that's sexually selected for as well.

Speaker 2 Yes.

Speaker 2 I mean

Speaker 2 some of the some of the song things are very, very

Speaker 2 obscure.

Speaker 2 A lot

Speaker 2 A lot of seabirds, things like puffins,

Speaker 2 the male and female look identical. You really can't tell the difference between them.

Speaker 2 They can, but we can't.

Speaker 2 And they're both brightly coloured. So there's a bird called the crested aucklet, which is a

Speaker 2 cousin of the puffin, which lives in the Pacific Ocean. And there was a very neat experiment done on that in

Speaker 2 the 1990s where

Speaker 2 they said

Speaker 2 they grow just a tiny little black sort of forward-pointing crest on the top of the head and their beak gets much redder in the breeding season. So they took some

Speaker 2 birds, caught some birds, and they lengthened the top knot on the head or shortened it. and then measured how long it took for that bird to acquire a mate.

Speaker 2 And by lengthening the top knot, you shorten the time that the bird takes to acquire a mate. The bird is more attractive.
And that was true for both sexes. So that's rather intriguing.

Speaker 2 That proved what we had suspected for a long time, that

Speaker 2 you can get mutual sexual selection. You can get choosiness in both sexes in some species for the same criterion.

Speaker 2 And then there's a bird in New Zealand called the paradise shell duck where the male and female are both smart but they look very different.

Speaker 2 The male has a black head and a grey patterned body and white wings. The female has an orange body and a white head.
They're both striking birds,

Speaker 2 but they look quite different. Now,

Speaker 2 clearly, you know, the females are saying, I want the male with the blackest head, and the males are saying, I want the female with the whitest head. Well, does that ring a bell?

Speaker 2 Do human beings have mutual sexual selection? Yes, we're both very choosy when we pick long-term partners.

Speaker 2 But we don't have the same criteria, do we? You know, male beauty and female beauty are different things, both on the outside of the body and possibly on the inside of the brain.

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Speaker 1 That's drinklmnt.com slash modern wisdom. Okay, so could sexual selection have shaped the human mind? We've talked a lot about birds so far.

Speaker 1 Let's bring it a little bit closer to home for what it could have done to us.

Speaker 2 Yeah. My book isn't about one ugly African ape,

Speaker 2 but inevitably, you know, one

Speaker 2 feels obliged to put a chapter in at the end

Speaker 2 about this. And I'm absolutely sure that sexual selection is going on in our species.
I'm also pretty sure it's mutual and not

Speaker 2 like the black grouse in the, in the, in which it's female selectivity that's driving male appearance.

Speaker 2 I think in our, both sexes are very selective. We're a monogamous species, at least socially monogamous.

Speaker 2 That doesn't mean we're necessarily faithful, and we can be much less select, much less choosy when it comes to short-term sexual encounters.

Speaker 2 But for long-term pair bonds, both sexes are pretty damn choosy about who they settle down with. That, after all, is the plot of every romantic comedy ever made.

Speaker 2 So what's going on in human beings? What are we selecting for?

Speaker 2 Well, clearly there are, you know, sexually selected features of bodies like breasts or beards or something that may be involved in beauty.

Speaker 2 But I think it's more interesting to look at inside the inside of the head.

Speaker 2 Because the human brain did something very odd. It exploded in size over a relatively short period of about a million, two million years.

Speaker 2 Maybe three, I don't know, but not a very long period.

Speaker 2 It accelerated.

Speaker 2 the increase in brain size was very steady until around homo erectus it suddenly takes off um and actually it's got slightly smaller again in the last um 50 000 years we we think it reached its maximum size about 50 000 years ago on average and that might be something to do with um you know agriculture enabling us to live on more meagre diets or something like that

Speaker 2 But it was very costly. I mean, the human brain is a huge

Speaker 2 user of energy.

Speaker 2 It takes a lot of energy to build it, takes a lot of energy to run it.

Speaker 2 Why?

Speaker 2 What's the purpose of growing such a big brain? No other species needed it to survive on the savannah.

Speaker 2 And if you say, right, well, it helped us get through the ice age on the savannah when the climate was very variable.

Speaker 2 Well, plenty of other species managed to survive on the savannah, you know, buffaloes and gazelles and baboons and chimpanzees in similar habitats and so on.

Speaker 2 They didn't need 1200 cc brains.

Speaker 2 So maybe it wasn't all about survival. Maybe it was about something else.
Now there's two other possibilities.

Speaker 2 One is that it was a social thing, that we needed big brains to understand the groups of people we were living in. We lived in big groups.
We were

Speaker 2 plotting and scheming and deceiving each other. So we needed big brains to figure out what other people were were up to, and that kind of thing.

Speaker 2 And that's a very popular thing called the social brain hypothesis. And that's obviously to some extent true as well.

Speaker 2 But there's a third possibility, which almost never gets discussed, but which was laid out in a very good book by Geoffrey Miller 25 years ago called The Mating Mind, in which he says, actually,

Speaker 2 this looks awfully like

Speaker 2 a sexually selected feature. It's a mental peacock's tail.
The sudden takeoff, the fact that it didn't happen to other species,

Speaker 2 and the fact that the things we use it for

Speaker 2 are not just solving practical problems or

Speaker 2 understanding how to get on with each other in society. We also use it very conspicuously for things like wit and humor, music and song,

Speaker 2 verbal dexterity, poetry, all these kinds of things,

Speaker 2 tool making as well, you know, I mean practical things as well,

Speaker 2 some of which looks awfully like showing off

Speaker 2 to the members of the opposite sex.

Speaker 2 So maybe it

Speaker 2 and you know,

Speaker 2 it's not at all difficult to see that people with

Speaker 2 great minds are attractive to members of the opposite sex in human beings.

Speaker 2 People, you know, with the verbal dexterity of George Clooney or the

Speaker 2 singing ability of Mick Jagger. You know, these guys don't do badly in the

Speaker 2 attractiveness stakes.

Speaker 2 I've chosen male examples, but I genuinely want to keep stressing that I think in our species it's going both ways. Humour is a very good example.
If you ask people, Helen Fisher did this,

Speaker 2 how important is humor to you in choosing a sexual partner?

Speaker 2 It scores very highly. And, you know, the personal columns,

Speaker 2 the the the um

Speaker 2 where people advertise for uh well i guess they don't do it anymore they do it on on site online but you know good sense of humor g so h is is a very important part of it and what what's the point of who humor otherwise you know and

Speaker 2 watch what people do with humor they show off with it you know they're they're not doing it to find out information from other people. They're doing it to impress other people.

Speaker 2 And that looks awfully like sexual display um so uh

Speaker 2 miller says and i think he's right

Speaker 2 that this isn't a slam dunk this isn't a proven idea but to spend the whole of the 20th century thinking about freud and marx and viaget and um you know all the other sort of theories of mind behaviorism and and and all these things without taking into account that the organ we're doing all this behavior with was probably subject to sexual selection and was probably being used to seduce as well as to survive.

Speaker 2 To do all that without taking that into account is a mistake.

Speaker 2 And we might have left an enormous hole within a lot of our social science, within psychology and sociology and economics and all these other disciplines, the hole being sex.

Speaker 2 And we need to put it back in there.

Speaker 1 It's mating all the way down. It was always mating.

Speaker 2 It's turtles all the way down. It is.

Speaker 1 So, you know, one of the things that you've mentioned there is this, I guess, bidirectional sexual selection that traits happen both not just male to female, but female to male as well.

Speaker 1 What determines whether it is unidirectional or bidirectional? And

Speaker 1 yeah, what does that sort of say about the environment and the child rearing

Speaker 1 and the expectations of that particular species? How does that all fit together?

Speaker 2 Yes. And the person who solved that problem was a brilliant evolutionary psychologist called Robert Trivers,

Speaker 2 who said something that's blindingly obvious, but none of us had thought of it before. And he said it in the early seventies.
He said,

Speaker 2 the species where the

Speaker 2 the sex that invests most in rearing the offspring will be competed for by the sex that invests least.

Speaker 2 So it's called parental investment.

Speaker 2 So, you know,

Speaker 2 but it's a vicious circle because, as I say, the red grouse, they both invest a lot in looking after the kids.

Speaker 2 The blackgrouse, they don't. The female does it all.

Speaker 2 So the black grouse, you get a huge amount of male-male competition to try to mate with females and a lot of sexual selection, less in the redgrouse. But which came first, the chicken or the egg?

Speaker 2 You know, did the parental investment come first, or the or the or the sexual selection come first?

Speaker 2 And the sort of exception that proves the rule here is

Speaker 2 those species of birds where it's reversed, where

Speaker 2 the

Speaker 2 brightly coloured, forward, and aggressive females compete for dull-coloured males because the males sit on the eggs.

Speaker 2 And

Speaker 2 I studied one of these species. It's called the grey phallarope.
It lives in the Arctic. Phalaropes, jicanas, dotterels, there's a number of species that do this.

Speaker 2 It's not very common, but it's not all that rare either.

Speaker 2 And it's, you know, the female is much more conspicuous, much more boldly coloured,

Speaker 2 much more, spends much more time displaying and

Speaker 2 much more inclined to

Speaker 2 fight with other females.

Speaker 2 So that kind of proves Triva's parental investment theory right.

Speaker 2 Now, in human beings,

Speaker 2 you can say that women do more of the work, and of course they do. They do gestation and lactation, which men can't contribute to at all.

Speaker 2 But compared with gorillas or chimpanzees,

Speaker 2 males do contribute an awful lot more parenting than most other grade apes.

Speaker 2 And

Speaker 2 we have less sexual dimorphism than most other grade apes. I mean, a male gorilla weighs twice as much, if not more, three times as much as a female gorilla.

Speaker 2 And he has a harem of six or seven.

Speaker 2 females. In chimpanzees, they have a multi-male

Speaker 2 system where each female mates with lots of males, partly to frustrate the tendency of males to commit infanticide, which they do in a lot of mammals to bring females back into fertility, probably in human beings, too.

Speaker 2 Look at the number of stepchildren that get killed compared with

Speaker 2 biological children.

Speaker 2 The

Speaker 2 murder rate is much higher.

Speaker 1 The Cinderella effect, as it's known.

Speaker 2 The Cinderella effect, exactly.

Speaker 2 So,

Speaker 2 you know, it's unfortunate that there's only four great apes: orangutans, chimpanzees, gorillas, and us, plus the gibbons are

Speaker 2 similar species.

Speaker 2 Because if there were 30 or 40 species of apes, then we could really do some good comparative analysis and

Speaker 2 see how we ended up with the mating system that we did.

Speaker 2 But I would argue that

Speaker 2 the need for fathers to be involved in provisioning and protecting offspring as well as mothers has been a feature of hunter-gatherer

Speaker 2 life for

Speaker 2 a very long time.

Speaker 2 And it has

Speaker 2 made us into a species in which females are going to be pretty choosy about

Speaker 2 males as well as males being pretty choosy about females.

Speaker 1 Are there any parallels between bird mating behaviours or whatever, and human romantic displays or social structures?

Speaker 2 Well, it's hard not to watch some of these bird displays

Speaker 2 and not draw parallels with nightclubs and other things. You know, there's a strutting that both species do, I suppose.

Speaker 2 But

Speaker 2 I think that's mostly anthropomorphism.

Speaker 2 We human beings,

Speaker 2 well, I think song is actually the most intriguing one, because there's no other mammal that is as interested in singing as we are, with the possible exception of Gibbons

Speaker 2 and one of maybe howler monkeys. But,

Speaker 2 you know, we

Speaker 2 song and language are

Speaker 2 very

Speaker 2 unique and remarkable human features, and they feature heavily in seduction and display.

Speaker 2 That's true of many birds as well.

Speaker 2 And the complexity of song in birds is truly extraordinary. The number of different phrases and different motifs.
Oh, sorry, I've left out whales, haven't I? Whales really sing as much as we do.

Speaker 2 So they're another

Speaker 2 example.

Speaker 2 But

Speaker 2 I think

Speaker 2 when you try and teach a chimpanzee to speak, it's really tough. And you can get up to a few hundred words.
You can't get grammar. You can't get syntax really to speak of.
Same for a gorilla.

Speaker 2 When you try and teach a parrot to speak, and this has been done, there was a famous African parrot called Alex who had an enormous vocabulary and really seemed to understand grammar in a way that

Speaker 2 most other animals can't.

Speaker 2 you know, the word order or whatever matters, you know, in terms of what it means.

Speaker 2 In that sense, there are similarities between us and birds.

Speaker 2 Okay.

Speaker 1 Another similarity question, I guess. Do birds and humans have an innate appreciation for beauty? Is the drive for aesthetic pleasure some evolutionary force?

Speaker 2 There's a rather good quote from

Speaker 2 Darwin on this, which I'm rather fond of, which is,

Speaker 2 birds appear to be the most aesthetic of all animals, excepting, of course, man, and they have nearly the same taste for the beautiful as we have. And, you know, he's really flirting with a dangerous

Speaker 2 idea there

Speaker 2 that, you know, there's something uncannily similar about us and birds here, because there's no reason why.

Speaker 2 you know

Speaker 2 it's convergent evolution if if we and birds have have this similar taste for the beautiful. And one of the things that

Speaker 2 I've been thinking about is

Speaker 2 it's unlikely to have been inherited from a common ancestor, this taste for the beautiful, because

Speaker 2 our common ancestor with birds, we now know, lived about 400 million years ago. That's an awfully long time ago.
And we know what that common ancestor looked like, roughly.

Speaker 2 It was a lumbering reptile that lived in a swamp.

Speaker 2 It gave rise to both the dinosaurs, which gave rise to the birds, and to the so-called mammal-like reptiles, which gave rise to the mammals.

Speaker 2 So we're not close cousins, descended from a creature that had a sense of the beautiful, probably.

Speaker 2 Maybe we are, but it doesn't seem likely.

Speaker 2 It seems more likely that

Speaker 2 we have ended up with an appreciation of color and tune and song and melody and

Speaker 2 fashion and all these kind of things and so have quite a lot of bird species and it just so happens

Speaker 2 that those have ended up with similar outcomes now why might that be

Speaker 2 well notice that

Speaker 2 on the whole sexual selection goes for pure colours not browns and greys so it goes for limited number of wavelengths you know limited number of frequencies um pure hues.

Speaker 2 Not, you know, if you've got every hue you can think of, then you end up looking brown.

Speaker 2 And it's the same with song.

Speaker 2 If you just want to make a noise,

Speaker 2 a click or a

Speaker 2 roar or something, it's got every sort of frequency in it. But if you go for just specific frequencies, you get a whistle or a...
or a tone or a or a tune.

Speaker 2 And that's, of course, much harder to do. I mean, you can make a boring noise by dropping a rock, or you can

Speaker 2 paint something brown just by mixing lots of materials together.

Speaker 2 But to actually create something that has a pure colour or a pure sound is much more improbable, much more unlikely, much more conspicuous, much rarer.

Speaker 2 And that's why we find it

Speaker 2 that's why we use it in our

Speaker 2 sexual displays, and that's why birds use it in their sexual displays. Um,

Speaker 2 and and so there's a there's a sort of almost a thermodynamic idea at the root of this, but as you can see, I'm beginning to wave my hands a bit, and I haven't thought this one through properly.

Speaker 1 I like it. I mean, definitely the

Speaker 1 refined nature of it not being everything suggests that you're purposefully doing this one thing. If you're brown, this you didn't mean to be brown, you just are brown.

Speaker 1 But if you're such a pure color, if you're such a pure note or tone or sound or whatever, that suggests that there's been some thought put into it, some pressure selected for it.

Speaker 2 Yes, there's a sort of watchmaker aspect to it.

Speaker 1 What do you think, so you know, taking a broader picture here,

Speaker 1 lots of past failures in evolutionary theory, trying to work out why things were the way that they were.

Speaker 1 What do you think we should learn about biases in interpreting our nature?

Speaker 1 What we should consider, where things come from, given the replete history of us putting both of our feet in our mouths and getting stuff wrong all the time?

Speaker 2 Well,

Speaker 2 for me, the history of science always teaches the importance of humility.

Speaker 2 Overconfident rejection of maverick ideas is the constant theme of all science.

Speaker 2 But

Speaker 2 that doesn't mean that every Maverick who comes along waving a new theory is Galileo. Quite a lot of the time, he's not, or she's not.

Speaker 2 And

Speaker 2 for me,

Speaker 2 that's the big puzzle of my life is how do I know

Speaker 2 when to listen to a maverick and when to tell them to get lost? Because,

Speaker 2 you know, there are

Speaker 2 many, many scientific debates where you just want to say,

Speaker 2 oh, for God's sake, get real. That idea can't be right.

Speaker 2 And 95% of the time, you're right to have that attitude. But 5% of the time, you're being like the Catholics and being dogmatic and telling a perfectly sensible chap to get lost when you shouldn't.

Speaker 2 And this was true of Darwin generally, isn't it? He was a maverick and a heretic

Speaker 2 he had to work really hard to get taken seriously.

Speaker 2 And evolution was rejected and still is by many people.

Speaker 2 And it's true of his sexual selection idea, where he was rejected as a nut case in his lifetime and for quite a long time afterwards, and wrongly so.

Speaker 2 But,

Speaker 2 you know, since then,

Speaker 2 lots of of people have put forward fresh ideas about why birds are colorful.

Speaker 2 For example, to go back to this, there was a theory in the 1980s that it was all about warning predators that you were in good health and therefore there was no point in chasing you.

Speaker 2 Well,

Speaker 2 I don't really see why a kingfisher needs to do that more than a sparrow, but you know, maybe there's an idea there.

Speaker 2 And in general,

Speaker 2 I'm more frustrated frustrated by science being too dogmatic than being too open to new ideas.

Speaker 2 Yes, if you're too open to new ideas, if you open your mind too much, your brain falls out, as someone once put it. But

Speaker 2 I would like generally to teach the lesson that we need to be more tolerant of disagreement, of heresy, of mavericks,

Speaker 2 and give them at least the

Speaker 2 privilege of testing their ideas.

Speaker 2 That said,

Speaker 2 you often get told by people, I've got this new theory, and

Speaker 2 the line I always come back with was, how are you going to test it? And that often shuts people up. So it's lazy to come up with an idea.
It takes work to test it.

Speaker 1 Awesome. Matt Ridley, ladies and gentlemen, Matt, I'm a massive fan of your work.
I think this is really, really interesting.

Speaker 1 I didn't realize I was going to become such a garage ornithologist for the afternoon.

Speaker 1 Where should people go? Do you want to keep up to date with your work and what you've got coming out?

Speaker 2 Well,

Speaker 2 I have a website which I mostly keep up to date.

Speaker 2 It's called mattridley.co.uk.

Speaker 2 I am just about to get on Substack, I think, too. I can turn my stuff out there.

Speaker 2 But

Speaker 2 and I'm on well, I'm on Twitter. I'm not very active on Facebook and LinkedIn, but I try and be.

Speaker 2 And I write books and journalism as well.

Speaker 2 And

Speaker 2 the book is called, I should say, Birds, Sex and Beauty.

Speaker 2 What's the subtitle?

Speaker 2 The implications of Charles Darwin's Strangest Idea. Heck yeah.

Speaker 1 Matt, I appreciate you. Thank you.

Speaker 2 Thank you so much for having me on and allowing me to rabbit on at such length.

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