The Infinite Monkey Cage - The Science of Baby Making

Episode Date: December 4, 2024

Brian Cox and Robin Ince investigate the science of baby making - don’t worry, all theory no practice! They are joined by Professor Joyce Harper, Dr Ben Steventon and comedian Sara Pascoe to discuss how just two cells can turn into trillions, or in other words, how an embryo can turn into an embryologist. The embryo building processes across species are remarkably similar, yet there is still so much we don’t know about the beginning of life. Our panel discuss these unknowns, the latest in fertility treatments and what new capabilities might be available to future parents. It seems that artificial wombs may not be science fiction for much longer and scientists are closing in on being able to make egg and sperm cells out of stem cells. So yes, Brian and Robin could one day have a baby! Producer: Melanie Brown Executive Producer: Alexandra Feachem Researcher: Olivia JaniBBC Studios Audio Production

This BBC podcast is supported by ads outside the UK. World of Secrets is where untold stories are exposed. And in this new series, we investigate the dark side of the wellness industry, following the story of a woman who joined a yoga school only to uncover a world she never expected. I feel that I have no other choice. The only thing I can do is to speak about this. Where the hope of spiritual breakthroughs leaves people vulnerable to exploitation.

You just get sucked in so gradually and it's done so skillfully that you don't realise. World of Secrets, The Bad Guru. Listen wherever you get your BBC podcasts. BBC Sounds music radio podcasts. Hello, I'm Brian Cox. And I'm Robin Ince. And this is the Infinite Monkey Cage. Now today we are asking how are babies made? We really are. We've been given that responsibility. We know that obviously a lot of the tabloid newspapers will be furious, go, children as young as 17 told

by Radio 4 how babies are made. But we're not actually, we're not going to do the first bit of how babies are made, we're going to skip that bit and if you want to know how they're made apparently you can watch like Love Island or something like that, which was a reference we decided to use even though neither of us have ever seen Love Island. We don't know anything about it. All I know is you get eight records and instead of the Bible and the works of William Shakespeare you get I think it's Lady Chatterley's Lover and a Littlewood's catalogue from 1976. Today we're exploring one of the great biological mysteries. How does a

human embryo develop into a baby? Or how does an embryo become an embryologist? How do cells know what to become and how to arrange themselves into human form? So to help us unravel this mystery of life we have a professor of reproductive science, a professor of genetics and the author of an autobiography of the female body and they are... Hi I'm Ben Steventon. I'm an assistant professor in the department of genetics from the University of Cambridge. So our lab works on early development using zebrafish, chicken embryos and mouse embryonic stem cells and some of the species when we can get a hold of them. And the weirdest thing that anybody's ever told me about how babies are made relates to armadillos.

So apparently armadillos generate identical quadruplets every time they reproduce. So I'm Professor Joyce Harper. I work at the Institute for Women's Health at University College London. And I started my career as an embryologist. And this was back in 1987. And some of you may know the world's first IVF baby,

Louise Brown, was born in 1978. So it's quite a new field. And then I worked for about 25 years on genetic testing of embryos. I used to take some cells out of an embryo and do various genetic tests on them, which I think we'll come on to. So the weirdest thing that someone's told me about how they wanted to actually make a baby was an Italian professor who was very notorious. And he said that he had actually cloned some humans.

About 20 years ago, he said he had two women pregnant. And he said, don't worry, we don't need to clone women. We only need to clone men, because men are very concerned about their DNA. But women don't worry about their DNA. So he was taking men with faulty DNA Taking their partners very healthy egg with lovely DNA throwing their healthy female DNA away and cloning the men now He said he'd done it, but he disappeared. I don't know where they are. I don't think he did do it My name is Sarah Pascoe I'm a comedian and the strangest thing I ever got told about how babies are made is that you can get one from a toilet

seat This is our panel The strangest thing I ever got told about how babies are made is that you can get one from a toilet seat. Oh. And this is our panel. APPLAUSE Can I ask you, before we get started, I wanted to ask you actually, Ben. When you said other animals when we can find them, there was kind of that sense that you just... It was sinister. Yeah, it sounded like you go to the pond with a big net and see what you can capture. There was a level of kind of Robert Helpman's's child capturing chitty-chitty bang bang.

I mean, we'd love to do that. I mean, but generally... That's not the response I was expecting you to have, right? In any way, you've incriminated yourself there. Instantaneously. Damn those regulations. I think it's a solid point, right? I mean, actually, you know, often now in the field, we tend to focus on what we call model organisms,

so a small set of organisms that many people use. Clearly, there's advantages in that, because people are working with the same species every time, so we build up information. But a lot of interesting biology is out there that we tend not to access, because we don't do enough of this. We don't do enough of going out into the wild and seeing what we can find and putting under a microscope.

I think, you know, frogs are interesting newts yeah. So you want a school trip? I want my lab to be yeah just sort of get on a coach school trip. Be brilliant. Go to St Albans. So Joyce the first bit we want to deal with then so as I said we're skipping over the actual sex bit so immediately afterwards you can listen to a show with Robert Winston if you want to know about that. So that first moment when the sperm and the egg

have met, what are we seeing? So the egg's quite a big structure compared to the sperm. Women always have the advantage. It's the biggest cell in the body. Yeah, we're bigger and better. Come on, we've got these lovely big juicy eggs. So the sperm is just tiny, it's just a bullet of DNA and the sperm has to go on this swim swim swim journey and it fertilizes the egg and Then the egg is going to but what we call a zygote It's the very first stage of of development and it's a very early embryo and the cells will then keep dividing and dividing and dividing and dividing Until we make a baby. I thought there'd be more to it than that Now some music.

What about the bit, so anyone sort of my age, we all watched this film called Look Who's Talking and Look Who's Talking 2. So actually the imagery at the beginning of that film, which was sperms on their way to meet an egg, and something that we all kind of knew was that the egg stops all of the sperms getting in. there's like a decision making process. How does the egg decide? So the egg when it's first ovulated from the woman's ovary it's actually got quite a squidgy

frame around it so it's a cytoplasmic shell we call the zona pellucida. Once one sperm's got through it hardens and then what you can, if you look at a human egg that's had a few sperm around it, all the others got stuck, all the ones that lost, they just stick to the outside and they can't get in. So there's that one winner that gets it. Sometimes there are two that get through or more, and those are abnormal embryos and they won't,

they'll develop a little bit, but they won't go very far. Now we're using films as a reference point, and I'm older than you, so I'll use Woody Allen's Everything You Always Want to Know About Sex, but I'm afraid to ask. So in that, some of the sperm have existential anxiety. It is. Do we see that at all in the model? Oh, I think we do. It's a race.

You can remember they're all lined up, waiting to go, ready to go on their journey. So they've got a long way to go from the testicle. You know, but some of them don't make it. Some of them end up all sorts of places. But some of them are swimming. They're supposed to end up in the female genital tract and then go swimming through the cervix,

swimming through the womb down the fallopian tubes where this wonderful big gorgeous egg's waiting for it. This is a really fascinating thing. When we were talking about this beforehand, both of us were like, oh my God, there is so little that we know about this incredible process. So things like just on terminology,

can you take a sublasticis, embryo, fetus, how do we see the different terminology and what does that represent in terms of the development? Sure, as soon as you have a fertilized egg, you have the zygote, and then you go through these cleavage stages, so early cell divisions that give you the blastocyst stage. So then you have individual blastomeres that make up the embryo. So you're going from a single cell through to several hundred cells.

So the first stages of cell division, what is the process by which that cell starts to divide and then what are the processes by which those cells start to become different from each other? So every cell has the same DNA, so it has essentially the same blueprint as often it's described, they have the same sort of instruction manual, right? All the information is the same between all of these cells. What's different between all of the cells in your body is the genes that are turned on. And so it all comes down to that. You know, what parts of the DNA are going to be transcribed into these messages to then make proteins. So these proteins that are made in cells can do many different things. They might come back on and change the way that the cell expresses other genes, turns them on or turns

them off. So you have almost like a circuit diagram type regulatory logic that can happen over time. There's one cell turns on one gene, it represses other genes and then switches on another gene. So that can create a dynamic, right, changing in cell state over time. The other thing that cells can do is make proteins that will be released from the cell and maybe diffuse across a field of cells and then instruct them to say, you become this fate or you become that fate.

And then you go through this process called gastrulation, which sounds a bit like the name right, gastro, gastra, gastro, you know, gastropub, whatever. So you've got to form the gut tube essentially down the central cavity of the embryo, and this is really what it's about. It's taking a ball of cells into a multi-layered structure that has an inside and an outside, and that's when you really start to generate something that looks like an organism, right? So you set up the main body axes like head and tail, dorsal, ventral, left and right happens during this quite amazing process of gastrulation. And because of what it

looked like for a while scientists when they first had microscopes thought that human beings went through the whole stages of evolution in utero so they thought that was our fish stage that we were sort of going through everything they thought we had a little tail and stuff didn't they? Yeah exactly yes so that's the the idea of recapitulation. Based on Ernst Heckel's drawings, which were slightly accurate. But we do look like a fish. There's a lot of truth in that general description.

What it's really telling you is that there's a lot of conservation. The processes that build the embryo are very similar across different species. And so it's kind of like thinking evolution can't play with these early changes too much. So if you have a very complicated process like embryogenesis, if you make a change early on it's going to have many secondary and tertiary effects, right, a little bit like chaos theory, right, the idea that a butterfly flapping its wings, this side of world can create a hurricane on the other side of the world because a small change in a complex process can have lots of after effects. And is that true of sex as well because

young fetuses look, I mean you couldn't sort of sex them with the naked eye for quite a long time as well. So in development for human even when you have your 12-week scan we wouldn't be able to tell the sex then, the external genitalia that's starting to form at that time, they look exactly the same. So it's only around sort of 16 to 18 weeks that they start actually looking different. So on a scan, you might be able to pick that up. And is that why men have nipples?

That's a good question, why men, yeah. There's a controversy about whether we are all actually starting off as females. But there's some controversy, there's some truth in that because there's certain genes and hormones that need to kick in to change that sort of default female anatomy to become a male. So yeah, that's why men have nipples. Those nipples are formed before those sex hormones and genes involved with differentiating male and

female kick in. A lot of people I think probably might have initially thought once we sequence the human genome, it's like, ah, we've got the answer. And then lots of people have used wonderful metaphors. Some people are saying it's basically you, it's as if you've got now a whole bucket of letters of the alphabet. And you go, so now we know how brothers Karamazov is made. Just have to put all the letters in the order. And I think you said Philip Ball talked about this lovely thing. It's like having a dictionary going, here we are, the complete works of Shakespeare. You go, oh no, we've got all the words.

So how true is that in terms of what we're understanding from embryology and what we're understanding about why we end up in the shape and form with what we are? What is the gap that we're dealing with in terms of understanding?'s a big gap and one of the reasons I became a scientist because I wanted to figure out how life was made and how humans formed it was always one of my questions and then I started teaching organogenesis which is what this whole process is and it's a black box in the human so I used to give my students books at the beginning of the term and they were called human embryology the bit in the middle was science fiction. It was almost all extrapolated from the cheek embryo because when you're growing

the cheek embryo you can see that, you can see in the lab what's going on and we know obviously in rodents and things we can do experiments to do that but in the human once the embryo is implanted, in IVF we get that embryo up to implantation So we know quite a lot about what's going on through fertility treatment. But once it's implanted, there is a black box in human development that when you look at the books, it says, this happens on day 26, this happens on day 30. It is a bit science fiction.

We've really got to take that with a pinch of salt and we just don't know. I read something about lambs that they can keep lambs alive for quite a long time in a sort of synthetic womb environment. It's much further than it was, you know, ten years ago, and that there's some sort of hope to be able to gestate a mammal all the way to, I don't know how long a lamb's gestation is to becoming a sheep, but that's something, because that's science fiction, but that's

happening. I've been in a conference today called DECODE about the future of women's health innovation and we had a talk today about the artificial womb and it brings up a lot of ethical discussions about motherhood, womanhood, you know, something that we have always done that men can't do and it will absolutely happen. You know, Brave New World, Aldous Huxley with his amazing book, 100 years ago, he said that his main character was an embryologist, they'd be the person who decided whether we're getting an alpha, beta, gamma, and then everything would be done in the lab.

And that will happen. But that's not what they want the synthetic wombs for, just to clarify. No, but it will happen. But it would enable people who currently can't be parents or can't maybe biologically be parents or to give people the full choices, it would give those people that opportunity. Because there's lots of reasons that someone doesn't have a uterus or the uterus isn't working. So there's positives as well as ethical difficulties.

But there's a lot of celebrities now that are using surrogacy, they're not carrying their children. And I think there will be people who don't want to carry, women that don't want to carry a baby yeah and will choose this not when I did enjoy it particularly in the audience I didn't enjoy it it's not it's not enormous well I really thought because it's interesting when you talk about you know something that women can do men can't because I always felt that when Freud used to talk about penis envy and I think well I think it's far more likely that men have creation envy Yeah, because it seems and I wanted to ask you sir cuz you your first books what wonderful book animal Which is that autobiography of the female body and how much further do you think we'd be with understanding embryology if it was men that gave birth?

Well firstly, I'm gonna have to be really boring and so obviously trans men can have children and give birth so just Well firstly, I'm gonna have to be really boring and say obviously trans men can have children and give births So just just so that we make sure I know we're talking about something that is so such a gendered things We end up saying men and women but um, I think maybe the actual act of giving birth would be Even in terms like the pain relief and the comfort and those kind of things I think that's where the fact that it biologically does feel unfair comfort and those kind of things I think that's where the fact that it biologically does feel unfair. When I had my first child you know it'd been a lot the infertility, the IVF, the pregnancy, the C-section and then to find out if he wanted to have another one I was going to have to do it again. It's so

unfair. Yeah I've had two pregnancies and I didn't enjoy it particularly either but I think we have to think about when we take this away totally and it could all be done in a lab. Oh yeah. I think there's a lot of ethical issues and that people are discussing this. The artificial wombs is getting on the agenda really of a lot of agencies now so it's it's been in the press a lot even in the last couple of months even though it's n years away I never say how long but I've said to my students I'm sure this technology is going to be used if not for you to have children then your children definitely touch children Well, you also mentioned older sucks Lee there and I think you know quite often if people hear the word embryology

They make an immediate a bit like with AI. There's an immediate leap to Hal in 2001 with embryology There's an immediate leap to the hatcheries of brave new world, you know talking about Frankenstein and those kind of things So do you still find this there's an ethical battle before you've even reached a point anywhere near those ethics? Oh, yes, we are discussing the ethics of everything. So the three parent babies that we might discuss in minute and Genome editing I was part of the Nuffield Council Group discussing genome editing all of these things before they come in, we want to sit and discuss them. Not that we come to a conclusion, because I don't think we can and things move, but I think that in the next n years, we are going to totally change, or have the possibility of totally changing the way we have children, for sure.

How much do we know about these very basic processes? So you talk about genome editing for example, so you said well I'd like to convert this baby from brown eyes to blue eyes for example. Maybe that's a complex thing or a simple thing but how much do we know about how to do that? For certain things we know quite a lot so I said that I was used to test embryos for genetic disease so it's called pre-implantation genetic testing and there are companies now that will offer this for eye color. It's complex because it depends on the genes of the parents and things like perfect pitch perfect pitch is one gene. Things like sport and intelligence and other characteristics are much more complex and much more affected by the

environment but with genome editing if the parents aren't carrying those genes, we will be able to edit the embryo to have those genes. Absolutely for sure. I think in my lifetime, that's going to happen. I mean, for the large part, the sheer complexity of development means that it's not going to be that simple for many traits to be able to say, okay, let's make this CRISPR mutation to get this particular phenotype in the end. But it is true that, I mean, so I was at a talk the other day and somebody was saying how, oh yeah, so in the developmental biology textbook, you only have one page on human development, but there's four pages on armadillo development.

So maybe armadillos are pretty interesting, as I've described. So there's a real reason for that. But armadillos are pretty interesting, as I've described. There's a real reason for that. But of course, we do want to know about our own development. And a lot of what's going on in that realm at the moment is to think about how you can sort of build aspects of human development from stem cells in vitro. And so clearly, if you were to then build an entire human embryo, well, then there's the same ethical difficulties as you have I think with with a natural embryo right so but in terms of trying to build models of certain aspects of embryo development maybe early stages of development a potential windows into this black box I think to understand a little bit about

sort of developmental defects for example what is that on what are their cause are the potential therapies for this So that's an emerging field as well. Sarah, I know that you've been talking in your most recent live show about IVF. And knowing you as an autodidact, as someone who's curious about so many things, I imagine before you actually had IVF that you were someone who spent a lot of time researching.

And I wonder just what, in terms of your changing of understanding of ideas around embryology during that process? Well beforehand, I would have just said that they were clumps of cells, especially because of people's right to choose and knowing lots of people who, throughout my life, had had unwanted pregnancies rather than very much wanting them. I'd spent so much more time thinking about that and then when I'd had infertility and miscarriage to then suddenly think about the potential of a human being in something

that wasn't yet a human being and I'm not saying that it has rights but it has this magical potential that's the thing that's really changed for me actually like when you go through implantation which is quite a clinical procedure but it also is incredibly romantic not in a it's not sex but but it's not it's, you know, you're watching on a ultrasound and the people who do it for you understand that for you it is an incredibly important moment because this might be the moment that your child is conceived and usually for people that would be with they are, you

know, planning, it would be with a person that they they care about, hopefully, or it might not be, but you know what I mean? There still is a human interaction going on, but it's scientists giving you the potential to have children. And this might be the second that you meet them for the first time, and they're five days old as a blastosis. So that, for me, those moments. And of course, there's the other side,

if you know you don't have a pregnancy that implants but there's so much human emotion still in it and then now I have another thing where my two children were conceived on the same day they were both five days old and the first one was chosen because he was a strong embryo and then when we had another around so my second son was frozen for 10 months, which I just find so baffling now that he's alive. And he's just learning to crawl and pull himself up and sort of going dadada. And I'm like, what happened in the freezer? What's it like? How are you here? Like it's, when you say science fiction, it's something that my brain can't create a narrative to make it make sense and then I have drawn to the fridge at all though get away why you keep going back to the fridge leave the peas alone he's all sweaty and and now I have frozen embryos which I don't think I'm

going to use I'm 43 I'm so lucky IVF worked for me twice and it's odd because before I started this whole process, I would have said, they're cells. Chuck them in the bin. Let them thaw out. Feed them to a dog. And now what they are is, you know, frozen siblings. It's so odd because this level of science

is everything and nothing. It's the building blocks of life and the potential for life. And it's so important. And the ethics is so tricky. And the other side of it, you know, there's no... World of Secrets is where untold stories are exposed and in this new series we investigate the dark side of the wellness industry, following the story of a woman who joined a yoga school only to uncover a world she never expected. I feel that I have no other choice. The only thing I can do is to speak about this.

Where the hope of spiritual breakthroughs leaves people vulnerable to exploitation. You just get sucked in so gradually, and it's done so skillfully that you don't realize. World of Secrets, the Bad Guru. Listen wherever you get your BBC podcasts. One there. Wanted to ask you, just talking about that frozen embryo, I mean, 10 months of being frozen, what is going on and how is it possible to preserve

and then that to become life? They are totally in suspended animation just as when we freeze anything they're just on hold so it is it is quite amazing. I've been through seven years of fertility treatment I've got twins from frozen embryo transfer as well and I had four in the freezer. I had four in the freezer. But yeah it's so it's it is a miracle and when I started being an embryologist when you're an embryologist you know you're you're doing these things in the lab and you do think about it as life But then being the other side of the table when it was my embryos It does bring a totally different perspective to the whole thing

but we are with they're just in suspended animation until we warm them and Then you watch them grow again And as a scientist that is amazing and then when the babies when people bring their babies in before I had my own I used to be wow especially when I've done the embryo biopsy you know I'd taken some cells I'd ripped this embryo apart I was like show me the babies and they oh it looks okay you know yeah so yeah it's amazing. Can I ask about that then because at the cells at that stage they will just replace themselves so they will understand that something's missing or at that point it's so gelatinous that it's it's not specifically like you wouldn't bring a baby and go um where's its leg?

I worry so there are different views of thinking about the eight cell embryo. So the eight cells just before it goes to the blastocyst once it's gone to the blastocyst it started what we call differentiation so it started to to get those changes. So it's eight cells. Yeah, eight cells. But eight cells, eight cells in the old days, in the 80s and 90s, we used to biopsy eight cell embryo. Now we biopsy and freeze blastocyst, but we used to biopsy and freeze eight cell embryos. And we knew that we could take two cells from there and we wouldn't affect development but with the frozen embryos we froze eight but sometimes they didn't all survive so sometimes they did just degenerated we knew then that as long as we had half the embryos as we have four cells that could make a

viable baby so we know at eight cells the cells are still totipotent they could still make any part we know this from cattle and things, they've taken an eight cell embryo and made eight animals from it. So that word you said totipotent, so that's the cell can become any part? Totipotent. Totipotent. Aren't you all glad you came to this recording? Isn't it great now to be armed with the word totipotent? Can I ask a question about these cells and age? Because something that we all know commonly is that the older you get, the more difficult it might be to have children. But that's because the reproductive cells are affected by aging in terms of sort of

the sperm cells and the egg cells. It's mainly the chromosomes actually. So the chromosomes in the egg, I hope everyone knows that women are all born with the eggs they're going to have. So women, while we're sitting here, we're all women are all born with it eggs are gonna have so women while we're sitting here We're getting more infertile and the men are producing sperm forever So they will have any producing sperm and our eggs are dying So that's pretty rubbish, but a lot of female infertility. So what we call age-related female infertility

It's because of those chromosomes. So when we're born we've we've got about 2 million eggs by puberty We've lost most of them we're down to about three hundred to five hundred thousand by the menopause all the viable eggs have gone And as we age from puberty closer to the menopause those chromosomes in the egg They just get more and more confused. They're in the middle of the process called meiosis, which you don't want to think about It's very complex, but it's quite a multi-stage process, meiosis, and it's used in the formation of an egg and sperm and those chromosomes get more and more confused. So it leads to decreased chance of getting pregnant, increased chance of miscarrying and increased chance of having a chromosome abnormality in your child, such as Down syndrome.

You can't leave it at that, meiosis, go on. One minute without hesitation.. Oh my god. It used to give me a headache. I think it give me headache now Do you want to do my oh, no, you can do Do you want to give it a go Around at the moment something I heard. Okay, this might just be gossip on the female comedian. What's that? So I heard that in terms of, you know that they used to have these old stats about you know a woman's chance to conceive after 25 because of the age of her eggs and actually what they discovered was that in terms of chromosomal abnormalities if you have a younger male partner you have

a higher chance of conceiving and that the egg and the sperm are quite good sometimes at correcting each other's abnormalities so if there are abnormal cells they can sort of balance each other out or cells can be corrected is this not no no I did have a younger boyfriend I can see where the comedians are coming from on that I will not be deflected it meiosis Oh god I was having a difficult time Well done though Sarah that was a really beautiful gesture to try and save the scientists from this embarrassment. So, meiosis. So, our eggs and sperm start off as all our other cells, they're diploid.

They've got two copies of each of our chromosomes. But what we've got to get in the egg and the sperm is we've got to get half the number of chromosomes. Because when the egg and the sperm meet, they need to give half the number of chromosomes. Because when the egg and the sperm meet, they need to give half the number of chromosomes each, so then we get a diploid person again. So you get your chromosomes from your mum, the chromosomes from the dad. So there's a two-stage process in meiosis

where a diploid cell, the stem cell, from the primordial germ cell, will divide, and it will halve. During that two-stage process, it halves a number of chromosomes. And it does all these lovely little things with these little chromatids and things. And that gives us genetic diversity.

But in women, it's a bit rubbish. And as we get older, it becomes more and more inefficient. And that leads to lots of problems. That wasn't bad. It was very good. Yeah. APPLAUSE Ben, we've kind of skirted around some of these things,

but to talk about the pragmatic things that we're hoping to learn from embryology in terms of changing the hopes and fortunes of human beings. What are the main things that we're looking at at the moment? I think it's important to recognise that developmental biology is a study of embryo development, is really the study of cells in action, right? And because we can use model organisms and we have great techniques to really look and follow what cells are doing,

we get to understand how critical processes of cell biology are controlled. You know, these questions are very important, right? Because if you think about cancer, that's essentially they're forgetting that programming, right, all of a sudden they're not doing the job of the cells that they're supposed to be doing, and they revert into the cell state

where they can divide a lot, become many different cell types again. So, and we know from studying embryo development that the same signals and genes involved in that process are what cancer cells are reverting to when they become a tumor. Similarly, in the embryo, cells have to move, migrate to different places, and there again,

the same genes and signals involved in controlling cell migration and motility in development are also being used by cancer cells in metastasis, for example, right? There's just some examples of how understanding the real critical functions of cell biology during development has quite a lot of implications. So that's one aspect of this, and the other aspect, of course, is understanding developmental defects. What are the genetic underpinnings?

Are there potential therapies that we could come up with to fix some of these problems. I was watching a lecture about the Habsburgs the other day, which is the kind of way I spend a lot of my time. And that fast, I just wondered what we can also, what we've learned using embryology when we do see a family tree that doesn't have enough branches.

Because there you see, again, talking about child development and each generation you've seen has an increasing number of limitations in many different ways. And has embryology helped us understand why it is that it's important to kind of cast the net widely and not marry your sister? You can marry her, but don't have children with her. Yeah, I mean, this... You know the air for us. You people us so free in academia, aren't you? It's like the 60s all over again.

So it's all about generating genetic diversity so it is important for healthy individuals, healthy populations to constantly increase diversity and diversity is positive in many ways as we know. You know we want to generate offspring, typically we want to generate offsprings with different genetic traits. In a way, we're sort of maximizing the ability of our genome to propagate into future generations by giving it more chances.

You roll the dice more times by creating more genetic diversity. Which brings me back to armadillos. So armadillos are very strange, right? Because why, why, why are they making embryos exactly for embryos the same with the same genetic basis, right? So this doesn't really make a lot of sense. Usually you'd want to create for maybe four embryos, but with different genetics because you want to roll the dice more times essentially. So that's why it's important. But what's the answer?

I don't know. I mean, I read those. Yeah, I don't know. I felt like you were going to say that's why. Do they all survive? Do they have high infant mortality? I think that's probably why. I mean, if you look at different reproductive strategies, right, in evolution, then there's many different ways you might play this. And it all depends on how your embryo and your children are going to be brought up in

what kind of environment. So if it's a particularly adverse early stages of development, then perhaps it does make sense to just generate four embryos at a time, because there's probably a high chance that only a couple of them will make it or one of them will make it. I'm just still thinking about the conception, because armoured plated creatures trying to conceive, that must be the... We're not talking about that aspect. No, I know we're not, but ahead but that's unfortunate back come to the infinite

monkey cage Robin stay on right a man keeps going on let me tell you about armadillos let me tell you question arm he goes, no more time for Armadillo. LAUGHTER Because we define this as post-sex. No, but by the time this goes out, it's going to be an Armadillo special. You know what the end result is. Sorry, Josh, you were going to say something. No, I was just going to say that, following on, it is strange that in so many cultures we encourage people

to marry people within their family or within their cast and within their community, which genetically is a really bad idea. But we've done it since the Egyptians and it's very strange because as you said, the ideal thing is to have children with someone who's as different genetically from you as possible to get that genetic diversity and to get healthy genes, you know, Darwin's evolution. You know, that's what we want. We want genetic diversity, not keeping everything in the family. But wasn't that, isn't that a financial decision rather than the biological decision that you go, oh no, if we marry into them, they'll get all our crowns.

Yeah, that's why, because attraction doesn't work that way. People are very, very attracted to people who have different backgrounds and look very different to them. So obviously we know what we're doing. Joyce we're quite near the end of the show now and I just wondered what in terms of in your career so far what what now do you look forward to? What are you thinking you know are you hoping we're quite near to in terms of breakthroughs in embryology? I just finished our module with my students about new technology in reproductive science. So we literally discussed this in detail on Friday.

Hope is not quite the word I'd use. Fear is the word I'd use, because all these things are going to happen, and they're getting close. So getting very close to making an egg and a sperm from a stem cell. So say, for example, if I needed to have an egg or sperm, we could maybe take some of my skin and we could, we're able to zap that in the lab now and we've done it in other species, done it in

rodents and I know lots of people working on this, it's going to be very very close. When that happens, I talked about age-related infertility earlier, when that happens there will be no age-related infertility because we could make a new egg for a woman or for a man at any age. So that's going to totally change how we have children. So that brave new world, I think, is really knocking on the door. And I think- Would you have a baby with yourself?

Theoretically, I think you might be able to. It's a little bit scary. So I'm nervous, and it's not going to be cheap. So it's going to be a big class divide about, I mean IVF is not cheap anyway. It's a big problem and this is going to really accentuate that. And then we've got genetic testing that will increase. We've got genome editing and then we've got the artificial wombs. This is all happening really, really soon. So you'd really be saying that a 90-year-old could,

if you had artificial womb technology as well, you could just routinely have babies, any age at all. Or legislate, I guess, to stop that. Or legislate. Within the next 20 years. And the worrying thing is that I've left lots of my cells here. We all have. So all of you, we could take bits from the atmosphere from everywhere and we could theoretically make your child. I'm being honest. I think that's a good idea. I have to admit, I'm going to populate the nightmares. Our producer specifically wanted me to ask, could Robin and Brian have a child together? I wondered what you were miming at them. They could definitely have a child together at some point in the future.

I'll get my hat ready for the christening. We'd like to have Brian's looks and Brian's brains. There must be a legislation that's going to stop this. I'm sure they'll demand it. There is legislation. So in the UK, we're the most regulated country in the world with regarding to fertility treatment. And listen, there will always be somewhere around the world where crazy things happen. Always. And there are crazy things, there are lots of crazy things happening already.

So yeah, when I said one thing I meant the the artificial eggs and sperm being one and then the genetic testing of them all being two genome editing of all three artificial womb for so I'll just see brave new world is here right now so this is essentially designer babies as you said you sit down and you specify what properties you would like your child to have and and that's essentially doable now, essentially, give or take. We are very, very close. Well, thank god climate change is going to wipe out our spaces. You always give us a happy, dystopian feature. Ben, was there anything left off that list you'd like to include? Yeah, I mean, well,

I think the next thing at the moment is organoids. I don't know whether people have come across this term, but essentially it's a switch from stem cells you can then take and differentiate into different cell types. And maybe you want to build a stake out of it, for example, or maybe you want to build some specific tissues from a disease patient and then test drugs on it

to see whether it's going to work with the patient or or not and now people are moving away from sort of 2d differentiation of cells to generating organoids which essentially are 3d structures. Are we starting to think about growing new a new heart for example for someone who's had a heart attack or liver and so on? Yeah potentially so you know replacement organs or even just sort of trying to scale this up so you could potentially do more sort of personalized medicine, for example. So if you know that, you know, if you have a drug that you know doesn't, it's not going to work in a third of patients, then obviously that drug's not used. But if you could actually just test whether it's going to have side effects

in those patients or not, then potentially it could be used, you see. So there's ways in which that could have huge impact, you know, in sort of replacement organs, but also directly drug testing. It's really fascinating just to finish because it's obviously there's the as you said the brave new world kind of horror stories that these technologies can lead to and so then the the instinctive reaction is stop stop doing this research but as you said there's the tremendous benefits as well it comes down ultimately It's not the science asserts the acquisition of knowledge But the way that we regulate this knowledge and deploy it that matters because there's no way in which we should stop trying to understand

These processes absolutely and I think that's why it's important to have these discussions and debates so that people can really understand what the potential Benefits are and you know, it's never really the case that scientists are trying to get to this point and have brave new world type scenarios I think that you know most people are wanting to do something it's going to be a benefit to humankind and guided through conversations with the public about you know where should limits be so I think that's really important. So Sarah apart from an increased level of optimism now in terms of how good it's going to be the extinction of the human race on the planet Earth. I think it's going to be the extinction of the human race on the planet Earth. I think it's going to be like a da-da we could make humans from nothing.

That's going to be the timing and then God will be like haha. You brought God into it quite a late state. That's the final twist Robin. I always forgot your final reveal. Bibles are available in the foyer. The, yeah, I just wondered anything else that you take from the show, just listening to the, because these ideas are... Huge. This is the cleverest conversation I've ever been part of, yet, like everyone else here, I just want to get my phone and Google

how do armadillos have sex. So we also asked the audience a question. I knew this was a dangerous question to ask. What would be the best way to make a baby? My heart goes out to Liz who says ask my mother-in-law. She has a lot of opinions and wants a grandchild soon One that hasn't left me unable to use a trampoline without wetting myself So Floyd said with a 3d printer to emerge already aged 18 and with a salary. What's he got there Brian? Paul says Lego. Because you can always change it into a

spaceship. Oh transformative. To ask Brian Cox very, very nicely. LAUGHTER It doesn't work, Cecilia. We made him human only as far as that bit of the neck. The rest of him, all smooth. LAUGHTER Martin said, no idea, but I wish I'd known before my teenagers were born. LAUGHTER A lock of Brian's hair and a test tube and we're seeing a pattern here now

we've just we've just said that that technology is on the horizon in a dual ninja air fryer for twins while listening to twins can only get better Brian Cox's of course with Brian Cox I just said Iogue. So, there we go, Brian, what a busy week for you. The boys from Brazil, isn't it? Look at all the children, all of the children, all of the same, all looking at the sky in wonder. Look at the children, anyway. Well, with that, thank you very much to our panel,

Professor Joyce Harper, Professor Ben Stevenson and Sarah Pascoe. So, thank you very much for listening. And next week we're actually going to see how much we've learnt from this week's episode because what we're going to be doing is joined by a panel of people that we've made using Petri dishes and apoptosis. If that doesn't work, three armadillos and if we can't get hold of those, just a couple of scientists and comedians. See you next time. Bye bye. In the infinite monkey cage Turned out nice again. my kind of person. For a different episode every single week from a vast range of your favorite comedians and freshest comedy talent, then listen to Comedy of the Week on BBC Sounds

from BBC Radio 4. Do it now! World of Secrets is where untold stories are exposed, and in this new series, we investigate the dark side of the wellness industry, following the story of a woman who joined a yoga school, only to uncover a world she never expected. I feel that I have no other choice. The only thing I can do is to speak about this. Where the hope of spiritual breakthroughs leaves people vulnerable to exploitation. You just get sucked in so gradually and it's done so skillfully that you don't realize.