Why Evolution Favours Beauty Over Survival - Matt Ridley

what was Darwin's strangest idea sexual selection by mate choice is the idea that Darwin had alongside natural selection and which he maintained was a very different process almost nobody agreed with him in his lifetime it was a failure in the sense that you know he couldn't persuade people that this was an important thing 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 I think he was on to something that actually when mates are selective which they are in many species it drives a huge amount of evolution in the other sex and it's a very different process from natural selection I call it the fun version of evolution because it produces colors loud songs and things like that it's less utilitarian yeah uh what was the reaction when Darwin first proposed sexual selection well he mentioned the idea in the Origin of Species very briefly and he said I think that he had a friend called Sir John sebrite who'd been breeding rather beautiful Bantam new new varieties of bantams and he said if a man can produce a beautiful bantom in a short time then why can't a female produce a beautiful male in over a thousand generations 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 a sentence saying um yeah look they are 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 and this made things worse because everyone else said I'm sorry are you suggesting that female birds are capable of athetic discrimination give me a break um 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 um partly these crusty old victorians were a bit uncomfortable with the idea of women having sexual agency at all of course let alone lust um uh so you know there one has to take into account that and um uh but I then I I'm very fond of a person who features in my book called Edmund Salo who was a um an amateur naturalist who watched the same species as me the black grous as well number of other species and and he he said you know Darwin was right the evidence speaks trumpet tonged in his favor which is such a nice phrase I think um because it's the you know 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 yeah I can imagine that Victorian England wasn't superbly keen on the idea of flipping the gender hierarchy upside down in saying well may you know maybe the males were shaped by female preferences and that also sort of has in it a sense of uh um almost sort of promiscuity in a way a degree of female sexual agency which again Victorian England uh probably not superbly uh popular 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 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 uh and so there's going to be you know different criteria but similarly choosing similar choosiness in both sexes but yeah no people people find it instinctively odd that women should be choosing that M females should be choosing males on the basis of appearance what is the the fundamental mystery when it comes to sexual selection the fundamental M mystery is why why so many species uh indulge in growing and displaying features that hinder their own Survival take a lot of energy and can be amazingly flamboyant 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 projector iridescent smiley face on it you know it it's what on Earth is going on it's it's such an eccentric outcome to come from evolutionary biology that that it it it it still doesn't where's the Rhyme or Reason is is is another way of putting it and and actually I see evolutionary biologists arguments over the last 150 years as being a ser of L last ditch attempts to put Rhyme or Reason back into this process and there might not be Rhyme or Reason it might it might be just be extravagant for your own sake because females are going to go for the most extravagant thing you can do um and I'll explain why I think that works as a technique yeah I I can imagine I can see especially in a 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 this is beauty incarnate I get to observe and enjoy you go ah maybe it wasn't for you right and uh the bird that Wallace and Darwin ended up arguing about most in 18 68 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 and these Wing feathers have a series of objects depicted on them that are clearly intended to be three-dimensional optical illusions in other words it they look like little spheres because they've got highlights at the top and shading at the bottom 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 like a sort of pebble or a or a jewel um and uh uh genuinely Darwin's critics including a guy called wood who was doing the uh doing the pictures actually for his book said look I'm sorry for to for this to be created by females female Birds you've then got to posit that females have an aesthetic sense 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 you know that's that was the implication of what he said um so there's there's there's there's real um uh you know you know um people like s Joshua Reynolds have been writing books about Aesthetics at this stage and saying you need to have been to Oxford to really understand Aesthetics um but sorry can I go back to one thing you said which which um uh intrigues me and that's the uh the idea of intelligent design because in some ways Darwin is flirting with something that looks a bit more like intelligent design here and it's been pointed out by elyn Richards and others who's a historian of this period that uh his 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 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 the um selective process 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 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 um 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 choosing what males should look like now Darwin isn't going that far he's not you know he's not literally saying that that that the females are sitting down and planning what they want peacocks to look like um but there is there's a little bit of um uh you know that that he's prepared to accept that that Evolution can be directed in a way that looks little dangerous to people like Wallace 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 you know what I mean that's a lovely way of putting it thank you yes um absolutely and and there's a plaintive quotation from him at one of his last meetings at the Len Society before he died where he says I still think I'm right I know all you guys tell me I'm wrong about by this point he's plead he's sort of pleading with theming as he's being I mean again look I I um 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 sort of begging for a bit of like guys 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 I I've read um uh Robert Wright's book was the the first one moral animal was what got me into evolutionary psychology again for wonderful book wonderful I that's that book is 30 years old now more than 30 years old it's like 922 or something it came out and for anyone that wants a a good s kind of half biographical look at Darwin's life with framing of evolutionary psychology there's some stuff in there that's a little outdated obviously three decades of a relatively new field so some stuff's moved on but it's so great but in that um Darwin seemed to be pretty sort of racked by self-doubt uncertainty he had like a little bit of a disposition toward low mood sometimes and uh I imagine he doesn't have the he doesn't get mad he gets sad and he doesn't have the big sort of [ __ ] you energy that a rade rebellious Anarchist thinker would have so I think he's actually kind of an unlikely um individual to to go so hard against the dominant sort of mainstream hedgemon that was what whatever came before him um and I do wonder what would have happened how much further his work could have got if 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 um it must have been really tough for him to navigate CU 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 it was this sort of H it's kind of there and I think I've got this inclination but I don't have something that's concrete and then if all of your peers are saying yeah mate you I mean you hit the lottery once with that thing but you don't get to run it you can't wheel it up and run it back another time um it's just isn't going to work yeah that that's all true I mean in is a cautious conservative establishment figure he's you know he's wealthy and mieses in upper middle class circles and uh and and 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 um Darwin is an unlikely revolutionary but in another sense I don't think you're right to say that the self held him back once he'd committed to writing the Origin of Species which was a 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 he compromised actually the later additions of the origin species are much less convincing than the early ones because he is trying to compromise with his critics and he's obviously you know feeling the pain of of some of the criticisms um but but he you know he then plows on finding all these stories about animals and plants and details that that that can butress his ideas and you know he there's no sense in which he um he sort of wants a quiet life well he does he doesn't want to get involved in the controversies himself but he wants to to keep pushing the ideas out there so he's a magnificent person but Robert Wright was the one who pointed out and I'd never never thought this before until I read Robert's point on it that um the way in which Wallace's letter from Papa Nini or from nug Guin was handled was quite cunning on Darwin's part um and that quite selfish actually we we tend to think of him as being magnificently generous and saying look this chap is has scooped me um but why don't we both present our ideas at the L Society together um 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 Lyle says look look um you poor chap Darwin don't get too head hump about it we'll have a meeting and we'll present your paper first and then Wallace's and you'll get the credit and so in a sense Wallace does get shafted by this process um uh and uh and Darwin for all his politeness can he's got a ruthless streak in him's he's got a ruthless streak and he wants his priority on this on this topic um but back to sexual selection um Wallace wins the argument in their lifetimes um and uh his and continues to really 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 um uh and and and some of the things win says in his dispute with Wallace are quite stupid actually for example Wallace said look female birds are mtled brown because they want protection on the nest they don't use the word camouflage because it hasn't been coined yet but that's what they mean um and uh and the the reason I know that is because female birds that breed in holes are often quite brightly colored things like parrots or King fishes or woodpeckers um and uh Darwin says no no no no I I I don't believe that females are camouflaged and you think why not and it's because he's he's desperate not to give an inch on the idea that uh that sexual selection is driving bird color why are birds so useful to use for this study what what is it about bir why is it not dogs why is it not cows why are we not using sheep for this study um birds are a bit more like us than many mammals uh they like song they like color they like visual things um we are we've got pretty good color vision for mammals most mammals have only got two color channels we've got three as have other primates um so we see a much more Colorful World rather like the world the birds see not nearly as colorful as they see they've got at least four channels they've got ultraviolet Vision all sorts of things so to some extent we can sort of empathize with birds 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 colors displays dances and songs in the birds that dwarfs other species so you just take song for example I was um out this morning when the sun uh came up and uh the bird song was fantastic at Springtime there was no mammal noise at all maybe I heard a sheep at some point um 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 um and song is quite a useful thing to study actually if you want to understand what's going on here um uh and so uh so without Birds well also you know bird watching gets a lot of human beings into natural history and then into biological sciences me I was a bird watcher before I ever thought of being a scientist um and that's true of a lot of people Jim Watson who discovered the uh co-discovered the structure of DNA um he was a bird watcher as a teenager and and and that's what got him interested in biology Etc so um uh I I think um now you could say butterflies dragonflies lots of sexual ornamented colors fish lots of bright colors but they're not as easy to study they're either to 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 with very few exceptions I mean there's a black one and a gray one and few monkeys have colorful faces but apart from that they're they're really G to look at and the noises they make are terrible really um uh and also they do a lot more sexual coercion than Birds um there's another way in which we're similar to birds and that is forming peir bonds to bring up Offspring birds do a lot of that most birds black gr are an exception peacocks are an exception but most birds the male and female collaborate to rear the young um and again we empathize with that in an awful lot of mammals all the work is done by the by the mother um both gestating and lactating obviously and and nurturing uh The Offspring so there's a sense in which we are honorary Birds okay okay so getting into the meat of it why do females choose certain males based on beauty and performance rather than obvious survival traits right so why not just choose a strong male who will give you strong children um and the answer is that you've got a there's a seduction going on it's it's a charm it's a persuasion it's not a a coercion that's the first point the second point is yes but why let yourself be Charmed by a flamboyant tale or bright colors or whatever and the argument that Wallace raised and that has reverberated sense through the topic is that it's a proxy for Fitness of some kind uh it's a pro it it it's telling you if you can grow that peacock's tail and keep it in good Nick and display it um frequently then you must be quite healthy you must have good disease resistance genes or something like that 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 but there's another thing going on that it's I think usually more important particularly when you get these exaggerated um flamboyant uh uh plumages um and that is the idea that uh Ronald Fischer first thought of in 1930 and was later mathematically proved by um uh Russell Landy and Mark kpatrick in 1980 and that is that the the fitness the females are after may not be just whether their offspring survive but whether their offspring seduce the the thing that really matters to them may be having offspring that can um persuade members of the opposite sex to mate particularly male offspring um and that it's no use uh choosing a ugly male partner that is particularly strong and diseas resistant so that you can have strong and disease resistant Sons if those Sons can't persuade other females to mate with them because they haven't got flamboyant Tales otherwise known as the sexy sun hypothesis the sexy sun hypothesis and that's a sort of runaway effect seduction of the hottest versus survival of the fittest is another way I I 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 okay so we have this sort of fisherian runaway selection thing thing going on that traits that are uh 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 the even before we get on risks and trade-offs why is it that there is such a thing as sexiness that isn't just utility of survival why is it not that maximized survival is sexiness why is there this other pathway this this other attribute right well the answer to that I think the clue to it and and I can't prove this and this is the problem with this version of sexual selection theory is very hard to devise experiments that prove it I will mention one in a minute but um the answer uh I think um is that the smallest 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 you can't stop it so and and so the clue is the fact that you get such extraordinary diversity of sexually selected ornaments in birds and other animals in other words there is no pattern you know there's no general practice that they tend to have eyes right it's not it's not always the biggest Tales it's not always the brightest it's not always the Tails it's not always the wings it's not always the crest it's not always the breast it's not always the back it's not always red it's not always yellow do you see what I mean um and when 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 in species like that um 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 the trag pan Which um uh 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 I've seen skin you why so so it's the very arbitrary nature of the features that I think argues for uh this process now you can still say yeah but why you know why would it matter 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 um so so they probably you know I in the in at the end of the book I say Hang on we're we're constantly trying to choose between these two theories Fitness and hotness if you like and um we shouldn't have to they're obviously both going to end up assist ing Each Other 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 uh they they end up netting out at the same outcome even if they sort of get there in different uh different paths yes but it might be worth mentioning that the what I think is the best experiment I describe in my book it doesn't uh it doesn't feature Birds unfortunately it features a small insect and it was done by Andrew balford and one of his students and I on a sort of Brazilian fly and what he did was he he took the he he allowed them to mate and in in the laboratory this is and the she actually it was she who did the work and I'm trying to remember her name but but Andrew student and um he he chose he bred from the uh 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 so he's now got the failures and the successes faring the Next Generation and he does that for several generations and then he says what's the difference between these um uh 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 are they less able to to persuade other flies to mate with them yes so that's quite a nice that's the the best experiment for teasing out these two hypotheses that that that I've come across that's really cool to understand that there is one dial for fitness and one dial for hotness and they maybe interrelated Upstream before them there is a something that causes them both to happen and maybe they do on average tend to happen sort of synchronously that uh fitter tend to be hotter I would also imagine that that's the case um but that they are distinct and they are interpreted in different ways so that's that's that's cool so just to kind of round out the fisheran runaway thing any minor advantage in terms of uh sexual selection trait display that a male has if it's even you know 5149 over time that will be selected for sufficent ly that it continues to get more and it continues to get brighter and it continues to get more elaborate 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 um extravagant displays yes although if the runaway process is as accelerating as Fisher thought then it not might not be a million years it it might be one of these things that happens really very quickly in a few thousand years and um uh 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 and one of the ideas I Toe with in the book is can we can we catch a species in the moment when it suddenly starts having a runaway selection um and come back in a thousand years and see what's happened um you need to I don't know I feel like you need to sew the seeds with uh girly daytime magazines you know that have got the new trend what to look for in this this Summer's new boyfriend or whatever and uh that's how you sort of inject it socially and from there the The Runaway begins well this is why I went to and sat for two nights running on top of a mountain in Norway um not allowed out of my little canvas blind from 8:00 p.m. to 8:00 a.m. um watching a bird that displays at midnight through the middle of the night called the Great snipe um of course it's not dark in Norway at that time of the year um and 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 doesn't look much different but this one does it this lecking males gather together and competitively display um and at the height of its display it flushes it the white feathers in its tail very and it's like turning on the light it's 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 and if you tipex some of the Mal's Tails so they're young people don't know what tipex is but you know if you put white paint on some of the male's Tails um uh you can improve their mating success according to uh some Scandinavian biologists who are very ingenious oh it's like a it's like a snipe aesthetician giving them some a beauty beautification augmenting so it's a boob job it's a boob job for snip exactly exactly um and so but my point is 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 so so maybe this is a species that's only just started having highly skewed sexual uh mating success so that one male gets to mate with 10 females which is roughly what happens um uh and that it hasn't had time for the tale to get huge and white and dramatic and and that might be about to happen the the conventional explanation for the great snipe is that uh it it's because it's often displaying in very poor light there's no point in being brightly colored um and and a lot of the display involves making clicking noises and maybe it's an auditory leg rather than a visual Leck but other birds make noises on the leg too so I kind of like my idea best that this is a species that's only just begun um to Leck uh there's another bird called a buff breasted Sandpiper which sort of lexs but sort of doesn't and I I'd like to watch that species for a thousand years and see what happens what's the Leck Paradox the Leck Paradox is that the black grous which Le live next door to the red gross which don't they pair up um so one male one female and they both bring out the kids therefore because the one male gets to mate with 10 to 20 females in the black gross but the other 19 or nine or 19 males on his leg don't get to mate at all that year the bird will have less genetic diversity in its population than the red gr it will uh be more genetically monotonous it will be more inbred 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 dis spers and so you know the the the species is fine in that sense but it it must be the case that there is less genetic diversity in a leing species like the black gross than a monogamous species like the red gross in which case there's less point in being choosy because the genes are going to be more similar I mean when you go onto aect you're bound to be looking at some half brothers because they tend to recruit to a el 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 um 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 you know making sure you get the very very best male and not settling for second best you know which the red grass do all the time they say look I just want a bloke CU going to look after the kids I don't care what he looks like um I'm anthropomorphizing but you get the point um uh the the the species that are most choosy have least reason to be choosy that is the Le Paradox um and I think the Fisher Theory shows you a way out of it um uh it doesn't matter how little variation there is you've still got to follow the fashion but it not really I mean you know I'm struggling with it too so it is a paradox and it's it's an intriguing one right so Birds that have these um speed dating which is kind bird speed dating is what sort of Leck the the the lecking is in a way yeah but speed dating where they all end up meeting with the same male remember yeah yeah okay good happen to you and me non- monogamous speed dating uh for Birds um in those situations you have a lot of the uh reproductive rewards acre to a few at the top yeah you also have to assume that that would mean the more sexually selective uh the 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 uh survival for that next Generation that comes along just due to some of the inevitable um reduced uh genetic diversity so you think okay 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 yes well the conspicuous plumage for a start is a threat to survival um the uh 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 uh present themselves but one way of looking at it is that the black gross and the red gross the males are putting in an awful lot of effort in in both species but the the the red gross the effort is going into um escorting the female defending the territory escorting the chicks helping the chicks Sheltering the chicks keeping a VI being vigilant over the family things like that whereas the black gross the effort is going into endless displays fights competitive dances and so on so you end up um uh deciding which way to to push your effort and when you push all your male effort into display you are wasting it as far as the lineage is concerned as far as the chicks are concerned in the sense that that you know so if I go out in June in the penines I can find a pair of red gross 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 um he's very valuable in that sense if I find a black grass with chicks there's no sign of the male he's miles away he's had his two seconds of fun two two months ago or whatever 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 and sure enough black grass seem to have have lower chick survival through that period of when chicks are small and indeed they they have smaller Broods actually so the species as a whole is not going to do as well 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 that's fascinating so sexual selection could actually be a maladaptive force sort of that pushes species toward an unsustainable extreme I me this idea has been around for a long time and there was a sort of rather cartoonish version of it that that was in Vogue for a while do you remember the ancient Irish elk um 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 Atlas but similar in shape to a Moose's Atlas and um uh how on Earth these poor deer managed to carry these vast antlers around um is sort of bit of a mystery and what were they for were they for fighting or were they for displaying and actually there's some quite good evidence that uh they might have been more about display than than than fighting based on how good they would have been at As Weapons if you like um uh but the the question of why that species went extinct used to be dominated by the theory that the antas got too big and the deer couldn't fit between the T between the trees when you're and my ancestor was running after them with a spear and so they caught them um 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 um and easy to find uh you know they wiped out mammoths and Woolly rhin ostes and steep bison and things as well um uh so at the end of the Ice Age it was doomed because it got predated by human beings not because um or because climate changed or something not because um uh they were uh the antas 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 um there was higher mortality among young than old deer as you'd expect in any species so um so that you know the the the um uh you can take these arguments about sexual selection being a handicap 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 how extreme can these traits become then well if you there's a little bird called the club wied mannequin which uh has a a display in which it makes a sort of um resonant twanging noise with its wings which carries a long way through the Ecuadorian cloud forest where it lives um and in order to make this noise the bird has had to redesign not just the feathers of its wings which are contorted in a sort of strange way but the Wing Bones themselves Wing Bones are generally the same in all birds I mean obviously there's a scale difference big birds and small birds but but the 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 not in this species it's got a sort of weird heavy club-shaped wing bone in its body I mean in its wing which is there purely to enable it to make a twanging noise in in the spring time or or the breeding season they don't have spring in on the equator um uh and uh and Richard PR has written about this in in his book The Evolution of beauty um and it's it's quite a it's quite an 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 a uh uh the the the the the there are um there's a bird called the Bulls pheasant which lives in Borneo where the male when he displays disappears into an enormous sort of white disc which actually comes from his tail and his head is then hidden by fleshy inflated blue tubes that stretch before and after the head um so he looks like a sort of plate with a blue knife on it 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 um uh to to submit it to these ordal but that gets to another point which I'm intrigued by which is that sexual selection can be possibly a more creative Force the 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 PR 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 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 Trion you know his a new outfit his a new fashion have a crack exactly yeah yeah and and I haven't mentioned the bower Birds but I've got to get them in at some point um Australia and New Zealand sorry Australia and New Guinea where Bower birds live um these are birds that have basically invented art um they build complicated structures not to nest in but to seduce females in it's the males that build them uh and they decorate them with uh colorful objects arranged uh in ways to enhance perspective and ways to look decorative and sorted by color and all sorts of things and and I watched a a great bow bird um at his bow trying to seduce a female with a red chili pepper um which he was displaying to her uh on the edge of a cemetery in Queensland in in in Australia um but his main um art in installation was a a huge patch of gray and white objects which snails cells and bird uh 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 um and this 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 what about um 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 yes um uh I mean some of the some of the song things are very very uh obscure um a lot of the a lot of seabirds things like puffins the male and female look identical you really can't tell the difference between them they they can but we can't um and they're both brightly colored so there's a bird called the crested orlet which is a cousin of the Puffin which lives in the Pacific Ocean and there was a a very neat experiment done on that in um the 1990s where they they said they grow just a tiny little black sort of forward pointing Crest on the top of the head um and their beat gets much redder in the breeding season so they took some uh 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 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 that proved what we had suspected for a long time that that you can get Mutual sexual selection you can get choosing in both sexes in some species um for the same Criterion and then there's a bird in New Zealand called The Paradise sheld duck where the male and female are both smart but they look very different the male has a black head and a gray patterned body and white Wings the female has an orange body and a white head they're both striking Birds um but they look quite different now 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 do human beings have mutual sexual selection yes we're both very choosy when we pick long-term Partners but we 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 okay so could sexual selection have shaped the human mind we talked a lot about birds so far let's bring it a little bit closer to home for what it could have done to us yeah my book isn't about one ugly African ape um but inevitably you know one feels abl to put a chapter in at the end let's Ser it 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 uh not like the black grass in the in the in which you know it's female selectivity that's driving male appearance um I think in our both sexes are very selective we're a monogamous species at least socially monogamous that doesn't mean we're necessarily faithful and we can be much less SEL much less choosy when it comes to short-term sexual encounters but for long-term per 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 um uh so what's going on in human beings what are we selecting for well clearly there are you know sexually selected features of bodies like breasts or beards or something that may be uh involved in in Beauty but I think it's more interesting to look at ins the inside of the head because the human brain did something very odd it exploded in size over a relatively short period of about a million two million years um maybe three I don't know but not a very long period it it it accelerated the increase in brain size was very steady until around homoerectus it suddenly takes off um and actually it's got slightly smaller again in the last uh 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 me more meager diets or something like that but it was very costly I mean the human brain is a huge uh user of energy um it takes a lot of energy to build it takes a lot of energy to run it why what what's the purpose of grow such a big brain no other species needed it to survive on the Savannah and if you say right well it helped us get through the ice age on the Savannah when the climate was very variable well plenty of other species managed to survive on the Savannah you know Buffalo and gazel and baboons and chimpanzees in similar habitats and so on um they didn't need uh 1,200 cc brains um uh so maybe it wasn't all about survival maybe it was about something else now there's two other possibilities 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 uh plotting and scheming and deceiving each other so we needed big brains to figure out what other people were up to and that kind of thing and that's a very popular thing called the social brain hypothesis and that's obviously to some extent true as well but there's a third possibility which almost never gets dis discussed but which was laid out in a very good book by Jeffrey Miller 25 years ago called The Mating mind in which he says actually this looks awfully like a select a sexually selected feature it's a mental peacock's taale the sudden takeoff the fact that it didn't happen to other species um and the fact that the things we use it for are not just solving practical problems or um 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 um uh verbal dexterity poetry all these kinds of things um uh tool making as well you know I mean practical things as well uh some of which looks awfully like showing off to members of the opposite sex so maybe and and you know it's it's it's not at all difficult to see that people with great minds are attractive to members of the opposite sex in human beings um people you know with the verbal dexterity of George Clooney or the um singing ability of MC Jagger you know these guys don't do badly in the um attractiveness Stakes um I've chosen male examples but I I genuinely want to keep stress that I think in our species it's going both ways humor is a very good example if you ask people Helen Fischer did this um how important is humor to you in choosing a sexual partner um it scores very highly and you know the personal columns the the the um where people advertise for uh well I guess they don't do it anymore they do it on on online but you know good sense of humor gso is is a very important part of it and what what's the point of who humor otherwise you know and 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 uh and that looks awfully like sexual display um so uh Miller says and I think he's right that this isn't a slam this isn't a proven idea but to spend the whole of the 20th century thinking about Freud and Marx and bi 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 um to do all that without taking that into account is a mistake 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 whole being sex and we need to put it back in there it's mating all the way down it was always mating it's Turtles all the way down it is um yes so you know one of the things that you've mentioned there is this I guess bir directional sexual selection that uh traits happen both not just male to female but female to male as well what determines whether it is unidirectional or bidirectional and yeah what does that sort of say about the environment and the child rearing uh and the expectations of that particular species how how does that all fit together yes and the person who solved that problem was a brilliant evolutionary psychologist called uh uh Robert triers um who said something that's blindingly obvious but none of us have thought of it before and he said it in the early '70s he said the species where the the the the the the the the sex that invests most in rearing The Offspring will be competed for by the sex that invests least um so it's called parental investment um uh so you know but it's but it's a vicious circle because as I say the red grass they both invest a lot in looking after the kids um uh the black grass they don't the female does it all so the black grass you get huge amount of male male competition to to try to made with females and a lot of sexual selection Less in the redgrass but which came first the chicken or the egg you know was the did the parental investment come first or the or the or the sexual selection come first and and the sort of exception that proves the rule here is those species of birds where it's reversed where uh the brightly colored forward and aggressive females compete for dull colored males because the males sit on the eggs um uh and uh the the I studied one of these species it's called the the gray fope it lives in the Arctic fer ropes jaas dools a number of um species that do this it's it's not very common but it's not all that rare either um and it's you know the the female is much more conspicuous much more boldly colored um uh much more spends much more time displaying and um much more uh inclined to um uh uh fight with other females um so that kind of proves triers parental investment Theory right um now in human beings 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 um but compared with gorillas or chimpanzees males do contribute an awful lot more parenting uh than most other great apes um and and we are we have less sexual dimorphism than most other gri ABS I mean you know a male gorilla weighs twice as much if not more three times as much as a female gorilla um and he has a harim of six or seven females in chimpanzees they have a multimale um uh 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 anal to bring females back into fertility probably in human beings too look at the number of stepchildren that get killed compared with um uh biological children the the the um uh murder rate is much higher there Cinderella effect as it's known the Cinderella effect exactly um so um you know it's it's unfortunate that there's only four great apes the rut tangs chimpanzees gorillas and us um plus the Gibbons are are similar species um because if there were 30 or 40 species of Apes then we could really do some good comparative analysis and see how see how we ended up with the mating system that we did um uh but I would argue that the the need for fathers to be involved in provisioning and protecting Offspring as well as mothers has been a feature of hunter gatherer life for um a very long time and it has made us into a species in which females are going to be pretty choosy about males as well as males being pretty choosy about females are there any parallels between bird mating behaviors or whatever and human romantic displays or social structures um well it's hard not to watch some of these bird displays and not draw parallels with nightclubs and other things you know there's a strutting that both species do I suppose um uh but I I think that's mostly anthropomorphism uh we we you know we human beings um well I 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 a possible exception of Gibbons uh and one of maybe Howa monkeys but um you know we song and language are very unique and remarkable human features and they feature heavily in seduction and display that's true of many birds as well and the complexity of song in Birds is is truly extraordinary the number of different phrases and different motifs oh sorry I've left out Wales haven't I Wales really sing as much as we do so that they're they're another um uh example um but uh I think you know we when you um 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 when you try and teach a parrot to speak and this has been done there was a famous African parrot called Alex Al who was had an enormous vocabulary and really seemed to understand grammar in a way that um any other most other animals can't um you know the word order or whatever matters you know in terms of what it means um uh in that sense there are similarities between us and and and birds okay do you another similarity question I guess do birds and humans have a innate appreciation for beauty is the the drive for aesthetic pleasure some evolutionary Force there's a there's a there's a rather good quote from um Darwin on this which I'm I'm rather fond of which is um Birds appear to be the most aesthetic of all animals accepting 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 um uh idea there um that you know there's something uncannily similar about us and birds here because there's no reason why you know it's convergent evolution if if we and birds have have this similar taste for the beautiful and one of the things that I've been thinking about is it's unlikely to have been inherited from a common ancestor there's taste for the beautiful because our 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 it was a lumbering reptile that lived in a swamp um it gave rise to both the dinosaurs which gave rise to the birds and to the so-call mammal-like reptiles which gave rise to the mammals so we're not close cousins descended from a creature that had a sense of the beautiful probably maybe we are but it doesn't seem likely uh it seems more likely that we have ended up with an appreciation of color and tune and song and Melody and and and fashion and all these kind of things and so have quite a lot of bird species and it just so happens that those have ended up with similar outcomes now why might that be well notice that on the whole sexual selection goes for Pure colors not Browns and Grays so it goes for limited number of wavelengths you know limited number of frequencies um pure Hues uh not you know if you've got every Hue you can think of then you end up looking Brown um and it's the same with song If you if if if you just want to make a noise uh a click or a 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 or a tone or a or a tune um and that's of course much harder to do I mean you can make a boring Noise by dropping a rock or you can paint something brown just by mixing lots of materials together but to actually create something that has a pure color or a pure sound is much more improbable much more unlikely much more conspicuous much rarer and that's why we find it that that's why we use it in our uh sexual displays and that's why birds use it in their sexual displays um 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 I like it I mean definitely the 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 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 yes there's a sort of watch maker um aspect to it what do you think so you know taking a broader picture here lots of past failures in evolutionary theory uh trying to work out why things were the way that they were what do you think we should learn about biases in interpreting our nature what we should consider where things come from given the replete history of US putting off both of our feet in our mouths and getting stuff wrong all the time well for me the history of science always teaches the importance of humility um overconfident rejection of Maverick ideas is the constant theme of all science um but that doesn't mean that every Maverick who comes along waving a new Theory uh is Galileo quite a lot of the time he's not or she's not and how for me that's that's the the big puzzle of my life is how do I know when to listen to a Maverick and when to tell them to get lost because uh you know there are many many scientific debates where you just want to say um oh for God's sake get real that idea can't be right and 95% of the time you're right to have that attitude but 5% of the time you're being like Catholics and being dogmatic and telling a perfectly sensible chap to get lost when you shouldn't um and this was true of you know Darwin generally is that he was a Maverick and a heretic and and and he had to work really hard to get taken seriously uh an evolution was rejected and still is by many people um and it's true of his sexual selection idea where he did he was rejected as a nut nutcase um in his lifetime and for quite a long time afterwards uh and wrongly so um uh but you know since then lots of people have put forward fresh ideas about why birds are colorful 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 well 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 um uh and and in general I'm more frustrated by science being too dogmatic than being too open to new ideas yes if you're too open to new ideas if you open your mind too much your brain falls out um as someone want to put it but um I would like generally to teach the lesson that we need to be more tolerant of disagreement of heresy of Mavericks um and give them at least the privilege of testing their ideas um that said there's a you often get told by people I've got this new Theory and the the the 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 awesome Matt Ridley ladies and gentlemen Matt I massive fan of your work I think this is really really interesting I didn't realize I was going to become such a a garage ornithologist for the afternoon um where should people go they want to keep up to date with your work and what you've got coming out um well I'm I I have a website which I mostly keep keep up to date I'm I'm it's called Matt r.co do.uk um I uh am just about to get on substack I think so I can CH my stuff out there um uh but uh um and I'm on well I'm on Twitter I'm not very active on Facebook and Linkedin but I try and be um and I write uh books books and journalism as well and the book is the book is called I should say bird sex and Beauty The Strain the the the um oh what did I what's the subtitle the the implications of Charles Darwin strangest idea heck yeah Matt I appreciate you thank you thank you so much for having me on and allowing me to RAB it on at such length do you think that your algorithm on YouTube is a bit of a God is it able to know things about you that you don't know about yourself well the YouTube gods have selected this episode specifically for you bespoke so go and go and check it out