Best Science Stories of 2025

0:16Hello, welcome to the Naked Scientist podcast, the programme where we bring you the biggest breakthroughs and talk to the major movers and shakers in the worlds of science, technology and medicine. I'm Chris Smith and in this episode we're going to revisit some of the most magical moments and scientific milestones that we enjoyed in 2025, including the incredible legacy of Dame Jane Goodall, the brainwave-reading bionic knee, why Labradors are so greedy and the beer that doesn't give you a hangover.

0:54But first, 2025 saw the birth of a baby girl called Amy who made medical history as the first child in the UK to be delivered from a transplanted uterus. Amy's mother, Grace, was born with a condition meaning she had no uterus of her own and therefore no prospect of a natural pregnancy. I spoke to Richard Smith and his colleague, Isabel Caroga, about how they helped to bring Amy into the world. This is a 25-year process whereby we very happily delivered a little baby, Amy Isabel, and she came from Britain's first transplanted uterus. And the uterus had been donated by the recipient sister called Amy.

1:36This is just fantastic, I have to say, for all of us. Such a happy family and really great to see. What was the reason for needing to do this, Richard? All the people who are coming to us for potential transplants are people who either don't have a womb, and most of those people have been born without a womb. So in this case, the patient had MRKH, which is a syndrome whereby you're born with no womb. But obviously no deuteris means no prospect of a pregnancy, and that's the problem you're seeking to solve here. Yeah, that's absolutely right. So up until now, the options for women were either continuing to go down the route of surrogacy, which is country dependent, So there's quite a lot of issues with surrogacy.

2:16Other option, of course, is adoption. Well, now we have this third option. Before we bring Isabel in, who is your partner in crime in this, talk us through what the process involves to get a uterus from one woman into another and then culminate in a pregnancy. I suppose the easiest way is to go back two years ago to when we did that transplant. Two sisters were admitted and there's the retrieval operation from Amy. it's a modified radical hysterectomy is the official term so it's a long dissection lasted about eight hours and five and then there's the implantation procedure that's led by Isabel Isabel does the vessel hookup and then I do the kind of genital tract anatomical hookup with the vagina and the ligaments etc.

2:59Do you have the two patients in the same operating theatre or the two of you operating in adjacent theatres Isabel where do you stand when does this get handed on to you? We have two separate theatres. Due to infection control, you can't have two patients in a same operating room. So the way it happens where we start the donor operation, when we are at a point in which the organ comes out, then it comes to a small operating room, side table in which we can prepare the organ for implantation. implantation. With any organ, the most important thing to do once it comes out is to remove the blood. We don't want little clots within the vessel in the organ, so we flush all the blood out.

3:51Once that we have the organ ready for transplant, then we can go with the organ to the other theater, adjacent theater. The recipient would have already been anesthetized. The operation, getting the vessels ready which are the vessels that are going to go and provide the blood supply already been made for us to join the uterus vessels onto so the organ gets its blood supply from the recipient. And do you see the thing as soon as you take the clamps off do you see the blood flowing and it go a beautiful red colour so you know you're in business is that how you know right we've got a good chance of this working absolutely so all organs when they're cold and when they're deprived of blood have a pale color and so when the blood returns into the organ you can see them changing color actually when you do kidney transplants that's absolutely amazing it's one of the wonders of what we do and so it's very similar in in the uterus and you see a changing colour and almost coming to life.

5:00One of the things that was occurring to me though, you are a transplant surgeon and you don't normally do uteruses. So how on earth did you get involved in this? And was it a steep learning curve to start doing uteruses? Well, the story of how I got involved was a long one, but basically Richard and his team were interested in doing transplant from disease donors. And I lead one of the retrieval centers in the UK. They just asked for some advice how to get into the world of retrieval. And it just developed into this true partnership. I have to say that I was initially quite reluctant. I couldn't see the need for this operation.

5:44I kept worrying about the risks. But it was only when I met the first patient and I heard the pain and what she had gone through that I understood the need for this operation and obviously I have changed my mind completely and I'm a true believer in that this is a very worthwhile cause. You must be delighted to hear that Richard, you've got a fan but you come in and do the final sort of close up and do the genital anatomy to make sure that's correct having got the the organ in situ now and yeah it looks like things are going well talk us through what happens in the in the days weeks months after that okay so there's really close monitoring going on we're doing cervical biopsies to look for rejection on a weekly basis at the start we're doing doppler flow ultrasound studies to look at blood flow within the muscle of the uterus that's called the myometrium and how long do you allow before you're comfortable to say right I think we're ready to try to get a baby in here now.

6:48So the minimum for that is six months but there's various other factors that are brought into that and certainly in this first case we actually ran that process out to just over a year. And when you decide that the time is right and it's safe to initiate a pregnancy where do the embryos that you're going to implant where do they come from? So they've all been created pre-transplant and they're all in cold storage and depending on age they've all been pre-implantation genetic tested meaning that we know that those embryos are genetically normal and that's one of the conditions to being able to come into the trial.

7:22And how many embryos do you put in? Oh one at a time only. You go one at a time and then how is the baby actually delivered? How do you decide when to deliver the baby and how? So the pregnancy is monitored as per any other pregnancy but there's A big issue for these women with a transplanted uterus that the uterus itself has no nerve supply so that they can't feel contractions. So obviously we were monitoring that very closely. The delivery itself is performed by cesarean section. The baby was delivered really beautifully, I have to say, and the baby cried within seconds of emerging into this world, which obviously for obstetricians is a marvellous noise, that's for sure, and for mum and dad, even more marvellous.

8:07Indeed. And at that point, does the uterus stay in and can you have more babies or does it have to come out? No, so the women have got a choice at this point. You can either have a completion hysterectomy six months post-delivery, but certainly not in the business of removing the uterus at the time of cesarean section, or you can go on and have one more baby and once you've had one more, you can then have your completion hysterectomy six months after that. And the purpose of that is to restrict the time the uterus is in to a maximum of five years. Were you both there for the delivery? Or did you only get to see them?

8:40So you actually were there when the baby came out? We were assisting at the delivery. So you're like surrogate parents almost in this. Must have been an amazing moment though to see you because that's 25 years of hard graft for you to get to this point. Yeah, there were a lot of tears shed actually. I mean, I'm not often rendered speechless but that day I was really very, very moving. Bet you never thought this was how your career was going to go, Isabel when you thought, I'm going to be a kidney transplant surgeon, end up making babies. Yes, it's totally a true new experience. As you say, I'm not often in a delivery room or seeing babies being born.

9:19So it was truly something very, very different and wonderful, actually. A lovely story. Richard Smith and Isabel Quiroga. On the 1st of October, news spread around the globe that the world-renowned primatologist and conservationist Dame Jane Goodall had died. She was 91. Will Tingle and primatologist Catherine Hobater at the University of St Andrews looked back on her remarkable life.

9:55I had two dreams. One dream, I wanted to work among, study, live among, learn from animals. And as I grew older and read more and more books, I realized that most of all, I wanted to go to Africa and work among and learn about African animals. And my second dream, I wanted to write books about them. So I feel that I've been incredibly fortunate to stand here and look back over my life and realise that to a large extent my childhood dreams have already been fulfilled. Jane Goodall was born in London in 1934. From a very young age, she showed a fierce curiosity about the natural world and would spend hours in her garden and nearby parks, notebook in hand, carefully observing the animals around her.

10:48As a child, she dreamed of distant lands and exotic animals, sometimes pretending to be Tarzan swinging through the trees. Later on, she would joke that Tarzan had married the wrong Jane. Jane's passion for animals stayed with her through her adolescence. She famously taught herself to read the naturalist books she borrowed from the library and was determined one day to travel to Africa. Her family encouraged her curiosity, even though such ambitions were unusual for a young woman at the time. She went on to study at the University of Cambridge in the 1950s, earning a PhD in ethology, a rare accomplishment for someone with no formal university science background.

11:27Her early work laid the foundation for her fascination with chimpanzees, the creatures that would define her work. In chimp society, and this is quite rare in a lot of the animal societies, any male, whether he's high-ranking, middle-ranking or low-ranking, even if he has a disability, he is able to sire an infant. And I think it is because of this ability of all the males with all their varied genes to sire infants that we find so much individuality. I mean, one chimp is as different from another chimp as one person is from another person. In 1960, Jane travelled to Tanzania to begin her landmark study of chimpanzees at Gombe Stream National Park.

12:10She was given the unprecedented opportunity to observe the chimps in their natural environment. Over decades, she revealed intelligence, emotion and social complexities like tool use, which were behaviours previously believed to be solely human. Her work challenged long-held scientific assumptions and inspired millions around the world. Catherine Hobater, a primatologist at the University of St Andrews, recalls how profoundly Jane inspired her own career. What Jane Goodall meant to me was this idea that you could be a scientist and a good scientist at that without necessarily having to become this idea of a sort of cold, objective observer of other individuals.

12:54that actually if you cared about the individuals that you were spending time with, if you got to know them, if you got to know them as having personalities, that that actually meant that you as a scientist could ask deeper, richer, more interesting questions about their world. And it was part of the goal of her mentor, Louis Leakey, when he sent her out there, was to send out somebody with a fresh perspective, to send out somebody who didn't have formal academic scientific training, because you would potentially be going in with an open mind. And it's not to say, you know, you have to be an incredibly good observer to see the details of behavior, you have to just have patience by the bucket load.

13:35And that doesn't necessarily have to do with thinking about hypotheses and predictions and scientific training. And actually, it, you know, she herself also talked about the fact that that lack of a scientific, a formal scientific background, really paid off in terms of her ability to see with a fresh perspective. And then she had just that incredible ability to share and connect everybody else to what she saw. Beyond her research, Jane founded the Jane Goodall Institute in 1977, dedicated to protecting endangered species and promoting environmental education worldwide. Jane Goodall's life was one of adventure and discovery.

14:14She endured the difficulties of living in remote African forests in order to study chimpanzees. Through persistence and curiosity, she became a leading figure in primatology and a powerful voice for conservation. From her childhood in London to her fieldwork in Tanzania, her story shows how determination can help reshape our understanding of the natural world. If she was here and she was around listening to all of this today, she would be the first person to say, don't be sad. What are you all doing talking about me and my legacy. There is a million things out there to do and we just really need to be cracking on with them to make sure that we're protecting chimpanzees.

14:52And I think that sense of urgency, that sense of the fact that every single person can do something, even if it's small, everything adds up, that sense of purpose that she was able to share with that positive message, that's the inspirational legacy she leaves behind. And that's what she would want us all to be doing, would be to make sure that we are not the last generation who will be having the privilege as she did to live alongside wild chimpanzees. And she was an inspiration to me. She played no small part in my decision to pursue a career in zoology and conservation. And one quote of hers that continues to resonate with me is, when you study animals in the wild, you realise how they live and understand the interconnection of everything and how every little species has a role to play.

15:35So you understand that everything is interconnected on this planet. And I believe to save everything else would be to save ourselves too. Thank you, Jane.

15:49Will Tingle reflecting on the life of Jane Goodall, who died on the 1st of October 2025. She was 91. In the summer of 2025, researchers at MIT announced the development of a new bionic knee prosthesis. The device is directly integrated with the amputee's bone and muscle, allowing the brain and the prosthesis to work together so the user can move much more comfortably and naturally. We talked to the appropriately named Tony Hsu at MIT to find out how it works. The prostheses that most people have, the ones that you can buy in the market, they help you walk, they help you go downstairs maybe, but they don't have any motors and so they can't move like human legs do.

16:34So in our work, what we did was we attempted to more directly integrate the prosthesis with the human so that not only can you exchange energy with the device, but you can actually exchange neural information to inform the device how to move directly. Is that purely motor as in movements, Tony, or are you saying you can get some feedback, some sensation from the prosthesis that feed that back into the person. So they've also got some awareness of where in space their prosthetic is and how much force they're putting through it. So the really cool part is that the way we approach the problem, where we integrate the prosthesis directly with the residual bone after the amputation, the person who has this prosthesis actually gets direct force feedback from that bone.

17:23Just like our skeleton is supposed to be directly loaded we take that same approach and we take advantage of all the rich sensors that we have in our bones and our tissues to actually provide that person's sensation of the prosthesis so even a very moderate tap all the way at the prosthetic foot can be felt at the bone just because of the way that we've designed the mechanical interface and what about that movement ability as well because that's the thing, as you say, when a person loses a body part, they lose the ability to move everything downstream of wherever they've had the amputation. So what have you done to try and address that?

18:04The technique that we use in this paradigm is called the agonist-antagonist myeloneural interface, which essentially takes muscles which used to be connected together and reconnects them after the amputation. So in this study, we provided people muscles that work together again, just in this case for the knee. But we take these muscles that already exist that used to control the knee and then we reattach them in a way that makes sense to the brain, that provides the person a sense of their phantom knee moving around in free space. So the person thinks they're going to flex their knee. This would normally extend or stretch the muscle over their thigh and shorten the muscle around the back.

18:50you can sense the activity in the muscles that would want to do that work out therefore what the joint would do and make the joint behave in an appropriate way so when it does move it moves in a way the brain's almost expecting it to i think that's actually a perfect explanation and then we call this the feed forward direction as in the signal comes from the brain and then the joint reproduces the movement that the signal contains and then in the feedback direction just like you mentioned earlier we get sensation from the prosthesis all these forces and impacts and movements that are conveyed through the bone back to the brain and so in this way we have the feedback direction and we close what we call the control loop and how does that work functionally what are the patients or the wearers say about this compared to devices that are much more dumb for want of a better phrase they're just a passive prosthetic that they're strapped on right it's like um it's night and day working with these patients in the lab when they come in and first start using our experimental device it's really an emotional moment especially because it's been so long for some of them since they've had movement of this joint so just even the ability to flex and extend a knee, just those two movements, right?

20:15Not doing anything fancy, not juggling balls or trying to avoid obstacles, just extending and flexing the knee. That can produce a really profound emotional impact on our patients. So people get to grips with it quite quickly. It's not a steep learning curve for them. They can actually master this and get to grips with it fairly fast. As scientists, I would say if we do our job correctly, then it's completely intuitive. the interface is invisible or seamless and the person just uses the motor skills which they developed since they're one or two years old right to move their residual muscles to move their phantom joints and then if we do our job correctly we can immediately reflect these at the knee given that it sounds from what you're saying like people took to this like a duck to water and really really genuinely appreciated it is this likely to become the gold standard then for above knee amputations this is what we would strive to offer patients from now on are you going in that direction this is definitely the school of thought that we are a part of we as in the researchers on the paper there are a couple of perspectives one is that if you make the device smart enough on its own like let's say use ai or really advanced math if you make the device smart enough on its own then it can do everything that the human would want it to do but the other perspective is that there are just some movements that you can't get the device to do, especially very fast and dynamic movements.

21:43Think again about playing football, perhaps, or dodging obstacles as you're running through a forest. There are some really dynamic movements that perhaps require human intelligence. And so we've taken this latter approach where we put the human in control. We put the pilot in the seat right and we really think that if you just provide a means for the person with amputation to express themselves physically physiologically then not only will they get a better movement out of the device but they actually feel more incorporated with the device and that's also extremely important for psychological well-being tony shu at mit now for over two decades snake fanatic tim freedy voluntarily injected himself with venoms from lethal snakes and willingly exposed himself to hundreds of bites he was on a mission to save lives and it was revealed in may of this year that antibodies found in his blood can actually protect against fatal envenomations from 13 of the world's deadliest snakes including even cobras and mambas.

22:51Now, a pharmaceutical company has used the genetic code from Tim's immune cells to copy the recipes for the antibodies he makes to help them to develop a universal snake-by-antivenom. I've been into snakes since the age of five, and that was actually my first bite by a snake. Not really that venomous, a roofing snake, and it scared me. But then I became interested in it, and ever since then it was going to museums or going to zoos or going out with my buddy's herp, in high school. Not for anything venomous, because we only have two venomous snakes in Wisconsin. So we're basically just chasing colubrids.

23:27We're chasing garter snakes and milk snakes, things like that. And then I got into the venomous snakes. I got into cobras. Tim began buying up these snakes from sources in Florida. He built a special lab in the basement of his home to house them. How many, though, I inquired? At the max, I had 60. 60? And what sorts of snakes? cobras, mambas just the ones that are responsible for some of the most lethal venoms that we know of was that what fascinated you? was it the fact that you're dealing with some of the most dangerous snakes or was there another motivation for being interested in those in particular?

24:05rustled wiper, soft-skilled wiper, fertile ants those are the big killers because they live next to people they just couldn't find them so I chose the next best thing which were cobras which killed a lot of people and mambas. For me, mambas was my major, major goal. Half my bites alone, over 100 bites, are just from mambas. They're just so dangerous. Indeed, about 20 years ago, Tim embarked on a mission to build his own immunity to help solve the snake bite problem around the world. Historically, we've made antivenom by injecting small quantities of venoms into animals like horses and then purifying the antibodies they produce.

24:41but it's not perfect it's expensive it's time consuming and the antibodies are not human which can in and of itself produce problems so how did tim approach the problem to build up his immunity and how did he administer this incredibly potent venom i was accidentally bitten by some colbers when i was milking them but i was also at the same time injecting venom so i had immunity but why were you injecting the venom to build immunity so i don't die did you just do that off your own back then so you milked the snakes got the venom and then you were just shooting up with it yeah didn't you think well i might die yeah and i almost did die a couple times what from injecting it september 12 2001 i had two cobra bites back to back in an hour and flatlined ended up in a coma in icu but when you injected the venom how did you know how much to inject and what on earth was it like when you put it in was it painful it's very painful it's kind of like a bee sting but way worse than that because like bees will yield one or two milligrams of venom and venomous snakes can go four to five hundred milligrams of venom.

25:43Were you using all of the different snake venoms or were you just focusing on one of your particular snakes at the time? Yeah no not not all out of the 600 no not all I focused on just individual snakes because that way instead of mixing venom I know what individual snakes feel like when I'm bitten by them or I inject venom because all snake venom is different. And it was that very long-term repeated exposure that's led to Tim's immune system producing a very powerful, very refined, but also very general response to the venom. He now has broadly neutralizing antibodies that combine to many different venoms and block them.

26:19But how does Tim's family feel about what he does? And why does his work actually matter? They look at it like it's the coolest thing in the world that I'm all over TV or all over the press based on what I do. And they realize that it's important for humanity, for the people that do die from snakebite, that I represent them, even though I'm 8 ,000 miles away. So that's the way I looked at it, is I'm representing people I'm never going to meet. So your immune response has enabled the discovery of the genetic code for the antibodies that can neutralize a lot of these venoms now, which is a massive step forward towards a universal venom antidote, isn't it?

26:55what will you do next then because as i understand it of the 19 that were tested you were able to help through what you've done with 13 of those 90 and that leaves a gap of some six so is this a question of exposing you to more snakes or are they going to use a similar approach to then get the final six but elsewhere or from animal studies or something what's the next step yeah they just have to pan out my antibodies and they have to figure out the ones that we need that we don't have right now um oh so you are still the source it's it's still going to come from you the solution yeah yeah yep i still give still give blood that's my main job is to give them blood that is such an extraordinary story that was the snake fanatic eager to find a universal anti-venom tim freedy the naked scientist podcast is produced in association with spitfire cost-effective Voice, internet and IP engineering services for UK businesses.

27:55Find out how Spitfire can empower your company at spitfire.co.uk.

28:03Music in the programme is sponsored by Epidemic Sound, perfect music for audio and video productions. This is the Naked Scientist podcast with me, Chris Smith, and today we are recapping the outstanding science stories of 2025. Still to come, what makes our pet Labradors so greedy, and a new booze-less beer that you can try out in dry January. But first, we're going underground. No, not to the 1980s hit for the jam, but instead onto the real London Underground to find out how quantum mechanics is being used to keep track of the oldest and one of the most extensive subway systems in the world. This story was first broadcast in February 2025.

28:43My guides were TFL, Transport for London, engineers Steve Foote and Steve Venables and Imperial College London physicist Joe Cotter. So the London Underground Network's really complicated and extensive. We've got 11 lines, there's 272 stations. We move approximately 1.2 billion people a year. We have 400 kilometres of track and then we've got five different signaling systems. So it's a really complicated system to operate. I've joked in the past but it's actually true. you're moving more people under the streets of London every day than the populations of whole countries, like Sweden, for example.

29:18I am still amazed at how complicated the system is and what we achieve each day, yes. So tell us about the problem that, as you see it, that having better positioning of trains could help to surmount. In terms of improving the way in which we maintain the asset and become more efficient and effective in the way that we do that, then having data is fundamental. Obviously, modern technology would allow us to use the train as a sensor, and it could run down the tracks, collect data around all those assets. And then if we've got an accurate positioning of where that train has collected that data from, if there's an issue, we know exactly where to go back to collect that data.