100 years of Sir David Attenborough

This BBC podcast is supported by ads outside the UK. In Wales, the country where this show is recorded, in 2004 only 15 out of 100,000 people made it to their 100th birthday. By 2024, that had almost doubled. 26 centenarians per 100,000 people. Scientists say that this can be explained by improved living conditions, better nutrition and a general improvement in public health. In fact if you want to feel good about the age we live in now why not take a moment to admire those advances in medicine. Better ways of detecting disease, better treatments, we have vaccines that stopped millions from being picked off by TB, measles, polio, flu and thank you antibiotics. We've also learned about the foods that spike your cholesterol and that smoking kills. There are of course always outliers. My great aunt for instance smoked for most of her first century and her 100th birthday card was a picture of her holding up a packet of cigarettes with the warning on it that smokers die younger. I'd like to think she would have made it to 200 as a non-smoker. I'm Marnie Chesterton. From the BBC World Service, this is Unexpected Elements. And to get this literal party started, more on that later, I have what every party needs, a couple of reliably brilliant science journalists. In Mumbai, India, we have Chavi Sachdev. Hello, Chavi. Hello, Kolata. And in Helsinki, Finland, Tristan Ahton. Hande hande babon, terve and hello. So this is Unexpected Elements. It's the science program inspired by the news. And for any new listeners out there, what we do is we take a headline, we use that as a springboard to jump off into loads of intriguing science stories. You can expect expert interviews. We've got listeners' questions, a bit of archive audio, and hopefully we'll learn something along the way. Now, I've mentioned centenarians, and here in the UK, there is one birthday celebration you cannot escape this week, especially if you consume any BBC content. But hopefully, it should resonate with listeners around the globe. Take a listen to this. The 8th of May is a significant day The monumental occasion TV legend turns 100 Sir David Attenborough Born in London in 1926 He's been doing this since the 50s Icon of broadcasting A steadfast champion of the natural world Changed the way we thought about nature He was the first person to show British audiences Some of these places and these animals Wishing a very happy birthday to Sir David Attenborough Yes, wildlife broadcaster Sir David Attenborough is turning 100 years old this week. This is a man who brought us 70 years of groundbreaking television. And I'm not just talking about the stunning natural history programmes. Sir David was also in charge of programming at a point where he could put the iconic comedy Monty Python's Flying Circus on air. And I think as we've talked about before in this show, he's also responsible for giving the UK its first colour TV programming. But mainly, this is a man who has brought us the secrets and extraordinary lives of the other species that share this planet. So let's use this show to throw him some sort of 100th birthday. Hooray! Does anybody know how David Attenborough has managed to live to be 100 years old? I'm going to say impressive genetics or maybe not doing cartwheels on clifftops. Is his diet and exercise? I'm pretty sure. I saw somewhere that he eats very little red meat now. Well, all of these suggestions, genes, diet, exercise, not behaving too stupidly, these are important. But a Swiss study has found that proteins may also play a pretty important role. Okay, proteins we might know from our diet as the stuff that we get from fish and meat and eggs and beans. They're also, when they're in the body, the type of molecule that does all sorts of things, from building tissues to making hormones and enzymes that regulate our metabolism. Right. And so Swiss researchers wanted to figure out how centenarians fend off metabolic dysfunction and oxidative stress, which can lead to accelerated aging. And what is oxidative stress, you ask? Allow me to explain. One of the metaphors I stumbled on is that if you think of your cells in your body kind of like a car engine, then you can imagine your cells using oxygen to produce energy. And as a part of that energy production, they create a kind of chemical exhaust, which is made up of highly unstable molecules known as free radicals. So as you age, those car engines start to break down and essentially leak an excessive and harmful amount of that chemical exhaust. But doesn't your body produce antioxidants that clean up the free radicals or that exhaust before it causes trouble in the body? Yes, but as you age, you don't produce enough antioxidants to clean up. So oxidative stress is the state your body enters when there are too many of these damaging free radicals. And that stress then becomes involved in a number of age-related conditions. Now, the usual cliche is my body is a temple. But I'm really drawn to this idea that we need to think of our body as some sort of car. Because I've previously made a doc about obesity. And someone had a really nice car analogy for the stresses it puts on you. And they said it's like you've got a roof rack that's overloaded. And your car's going to be fine at first. but it actually puts a lot of extra stress on the axles and things. I could see that. What car are we all being? I'm definitely some sort of a secondhand car. I need to go to the body shop. I want spares. Are we the car that we want to be or the car that we actually are? I mean, this is radio, so I can be an Aston Martin. No one's going to see that I'm actually a VW camper van. So it's fine. Back to the study, the Swiss 100 study. What did they find and where do the proteins come into this? So the scientists from the University of Geneva and Lausanne analyzed the blood of people 100 years or older and compared it with people in their 80s and much younger volunteers aged between 30 and 60. When they checked the blood work, they were able to profile 37 specific proteins in the centenarians, which were much closer to those of the 30 to 60-year-olds instead of the octogenarians. particularly those markers linked to lower oxidative stress. So the finding essentially suggests that key aging mechanisms are significantly slowed down in these 100-year-olds. Okay, so it's not just people reaching 100 being lucky. There's actually something in their biology that's helping them. Yeah, I mean, it's definitely true that the population has won the genetic lottery, But the researchers point out that genetics only account for 25% of their longevity. So as mentioned earlier, diet, weight, physical activity, these all play like a huge part. But what I found most interesting is that strong social ties are really fundamental to aging. So many of these elders like experience shrinking social networks as they outlived friends and family and siblings and spouses. But researchers found that it wasn't the quantity of social connections that mattered most. It was the quality of those relationships. I think what really struck me when looking through the research associated with this study, long life isn't just about genetics and exercise. It's care and love. And you're sort of living to live, not just to stay alive. People are really obsessed with longevity right now, though. I was reading an article about how people who live healthily when they're older have lived healthily all their lives. But do you have any guesses what animal could help us live longer? A turtle. They live a long time. They do. They do. They really, really do. Marnie? Yeah, but it could help us live longer. I'm going to go dog because people who have dogs have to walk them. And so you get the exercise and it helps you live longer. Both of you get extra points for being very creative and actually relevant. But the answer is in the name. It's called the Immortal Jellyfish. Drumroll. Have you guys ever seen one? No. Can't say that I have. All right. Well, let me introduce you to it. So its Latin name is Turritopsis dornii. It's rather tiny. It's about the size of your pinky fingernail. It's really quite lovely. And the deal is they don't die. Wow. Instead, adult jellyfish can return to their juvenile state if they get stressed out. Can you imagine if the human response to stress was turning into a nine-year-old? But these jellyfish, they rejuvenate. Does this mean that they just don't actually ever die? So they can die from disease or injury, but they don't die of old age. First, let me zoom out though and explain the life cycle of a jellyfish in general. So jellyfish have a pretty complex life cycle, and it includes both a sexual stage and an asexual stage. And in the adult, which is the sexual stage, the body is called a medusa, and it produces gametes, which are the egg in the sperm. And the eggs, which are fertilized by the sperm, develop into something called a planula, which is like its larval form. And these basically drop onto the ocean bed, attach to a rock or the seafloor, and then develop into a polyp. And polyps, they reproduce asexually by budding off immature medusas, which later develop into adult medusas. One scientist said it would be like if a butterfly was sitting on a leaf and then turned into a caterpillar. Maybe I should add that the medusa phase is the free swimming version of a jellyfish. So that's probably what people are thinking about when we think jellyfish. Exactly. Now, if you search scientific journals, there is suddenly a ton of papers who are trying to understand the biology of all this because longevity is now such a catchphrase. One I found interesting is from 2025, where Colombian researchers tried to figure out the underlying genetic and molecular pathways that allow the jellyfish to transform its specialized adult cells back into juvenile cells. So they want to figure out the specific markers of regeneration and maybe find parallels or absences in human biology. So what have they found so far? Could humans unlock their inner jellyfish and live forever? Well, they found that we humans do not have what the jellyfish have. But they did identify a complex molecular blueprint consisting of several interconnected genetic strategies. And they were building on earlier research published a few years ago, 2022 Spanish scientists compared the genome of the immortal jellyfish with its relative Tereotopsis rubra, which cannot rejuvenate as effectively. And they found that this immortal version had specific variants in over a thousand genes. So for instance, they have extra copies of genes involved in DNA repair. And another thing they found is that the immortal jellyfish maintains high cell plasticity. So a nerve cell could become a hair cell if they had hair. A better understanding of its biology could help with ways to enhance human tissue regeneration and come up with more efficient treatments for all the chronic diseases that are associated with getting older. So you just put the image of a hairy jellyfish in my head So I now wondering I think Tristan is too whether they got the genes to make like and what would the haircut look like Yeah exactly I imagining sort of like a Beatles bowl cut kind of a thing Yes, ditto. Thank you, Chavi. That was fascinating. Listeners, do you want to live forever? Please do tell us what your immortality project would be. Email unexpected at bbc.co.uk or you can WhatsApp us. plus 44 330 678 30 80. Still to come, Sir David Attenborough, but not as you normally hear him. Intrigued? Find out more after this. Hello, Ella here bringing you this week's Unexpected Elements quiz to celebrate David Attenborough's 100th birthday. In the 70 years David Attenborough has been presenting programmes about the natural world, he has inspired many people to name animals and plants in his honour. In fact, there are over 50 organisms that have been named after the esteemed naturalist. So my question is, which of these species is not real? A. The dinosaur Tiankosaurus atumburi. B. The flowering plant Sedevidea solanona. Or C. The echidna Zeglossus atumburi. Which of these species is not real? A, the dinosaur Tiankosaurus atumburi, B, the flowering plant Sodevidea solanona, C, the echidna Zaglossus atumburi. Have a think, and I'll be back with the answer soon. You're listening to Unexpected Elements from the BBC World Service. This programme is a celebration of 100 years of Sir David Attenborough. So we thought it would be fun to speak to someone who lives on Sir David Attenborough, the research ship, of course. I'm pleased to welcome marine ecologist Nadine Johnston of the British Antarctic Survey. Hello, Nadine. Hello, Manny. Tell me about Sir David Attenborough, the boat. What is this boat for? It's all set up for polar research. So she can go down to the Antarctic, into the sea ice and crush its way through. and she can go up to the Arctic, but she can also operate in any other oceans as well. It's got an amazing amount of well-equipped and spacious laboratories. I think we have about 12 laboratories on board. So we can get on board our physicists, our biogeochemists and our biologists and gather data in a way that we haven't been able to do before. Now you've come off Sir David Attenborough in order to talk to us because it's five o'clock in the morning and you don't want to wake your colleagues up. But where is the ship right now? So we're down in South Georgia, the island of South Georgia, which is in the sub-Antarctic. And it's an incredible island. It's a really biologically rich area of the Southern Ocean. You have some of the largest colonies of penguins, of seals. We have a huge concentration of whales in the water. And we also have a huge population of what we call zooplankton. So these are small free-floating animals in the ocean. I think most people will probably be familiar with one of the most iconic, which is Antarctic krill. It's a very special place for me personally to be able to work as a marine ecologist and see all of this biology on our doorstep. And you're not just seeing all of this biology. You are studying all of this biology and the physics and the chemistry, right? This is a huge project. Tell me about that. Yes, we're part of a really special project called Biopol. It's a five-year program. So we've pulled all of our expertise to understand, try and understand one of Earth System Science's most complex questions. And that is how the polar oceans, both in the Arctic and the Antarctic, export nutrients and carbon which support global ocean primary productivity. So underpinning all of that marine life that lives in the ocean, fisheries and also helps importantly to regulate our climate. What makes you think that the polar oceans are important for that? We know that in the mid latitudes around the tropics those oceans are quite nutrient poor. But if we look at the oceans in the Arctic and the Antarctic they're actually in most of the areas quite full of nutrients. That made us think, okay, where are these nutrient sources coming from and how are they actually getting to those mid-latitudes? So biopole has been mostly about trying to pinpoint, to track and trace, what are those key sources of nutrients in the polar regions? So we've been looking at sources from glaciers, from rivers and from land, and also from upwelling processes that happen in both of those oceans and also from the sea ice. And then we have this global ocean circulation system and then that travels around the rest of the world, kind of popping up a bit, if you like, in the equator and then back up to the poles again. So there's this conveyor that's able to take those nutrients all the way around the globe. To me, you're painting a picture of the poles being this kind of the fridge of the oceans, the place where all the food comes from. Exactly right. So that's the overview. What are the holes in the data that you're looking to fill? One of the processes that we're really interested in is the way in which zooplankton are able to take carbon down to depth. So we have some really nice data from the Arctic that there are a particular species, a group of animals called copepods, which in the polar regions have a really nifty way of dealing with that wintertime dilemma of no food in the water column and predators around. So they feed really happily on phytoplankton, those marine microscopic plants in the summertime. And then they take all of the carbon that's bound up within the phytoplankton from their photosynthesis and turn that into a carbon-rich fat sack in their body. And if we imagine that the biomass of these copepods worldwide is about 10 times that of the human biomass. Wow. And then as the autumn progresses, they go down to depths of 1,000, 1,500 meters and hang out in the water column away from their predators where they're respiring and they're releasing that carbon that they've stored in their fat stores into the ocean. So what we're trying to understand is how many of these copepods are there, where are they distributed, and how much carbon are they capable of taking to depth. We have data for the Arctic on these species, but we have absolutely nothing, no information on them in the Antarctic. And already we think that for the Arctic alone, that this process of taking carbon down to depth or sequestration, as it's called, could be in the order of two to three times that of the Amazon. Those are stonking numbers, given that the Amazon's known as the lungs of the world and there's all of the stuff about them breathing in the carbon dioxide. So actually more is going on at the Antarctic, you think? Yes. So you're getting a picture, a snapshot of the underwater world that just most people will never see. I'm wondering about what you see on the surface. Have you seen any of those huge icebergs that have been breaking off? Wow, yeah, we have been incredibly lucky. We've seen not one, not two, but three icebergs. and they are vast. I think the first one that we saw was about 76 kilometres long and about 45 kilometres wide. And then in our next cruise, we came across A23A. When you're on the ship, as far as the eye can see, left and right is just a wall of ice. That sounds incredible. Also kind of a bit scary, because it's kilometres of ice coming towards you, Yeah, it is scary. And there is a minimum distance that you have to keep away from that iceberg, because if anything falls off, you've got a tsunami that can come towards you or the ice can come back up and hit the ship. I think it was a really surreal moment the first time that we came across the A-23, because there we were standing on the Sedeva D'Anbra ship with this iconic, amazing person embodied in the ship. And by the way, he also appears on the tannoy of the ship. Sometimes you'll hear his voice say, warning, there'll be a fire drill. It's quite surreal. And you're like, oh, it's fine. It's David. It's very calming. It's amazing. But as we were standing on the ship looking at this iceberg, it was this surreal moment of here we are on this ship with this iconic person standing at this most amazing view and a pod of orcas just appeared and they were swimming in front of the iceberg and the iceberg has these beautiful cave systems in front of them and then you have these gorgeous black and white glistening bodies just bobbing around playing in the waves yeah really surreal. I feel like I'm talking to someone who really loves her job which is great. Thank you so much. Thank you for having me Marnie. It's been an absolute pleasure. So, inspired by Sir David Attenborough, we've discovered why some people get to blow out the candles on their 100th birthday cake. We've found out about a jellyfish that never gets old and we've just heard about what it's like to live on Sir David Attenborough. Still to come on the show, we'll be unwrapping the science behind landslide prediction, we'll be finding out about the speed of sight and I'll be discovering what new research on edge species has to do with Sir David. Stay with us. Use hundreds of templates and start your own design studio in no time. Thanks to smart AI tools, you write perfect text and you can see the photos of your products. And while you buy, you sell Shopify the rest. From the supply of supply and international processing to return. Want to buy a big business? Start for 1 euro per month and start today via Shopify.nl. leading their groundbreaking voyage around the moon. Splashdown confirmed. Humans are back in the business of going to the moon. But while the mission is over, the Artemis space program is just getting started. 13 Minutes, the BBC Space podcast, is looking back on their epic journey and discovering what the future holds for the Artemis space program. Just imagine what we as humans can do next. 13 Minutes presents Artemis II from the BBC World Service, Listen now wherever you get your BBC podcasts. This is Unexpected Elements from the BBC World Service. I'm Marnie Chesterton in Cardiff in the UK and this week I'm joined by... Chavisaj Steve in Mumbai, India. And... Tristan Atone in Helsinki, Finland. This week we are mainly marvelling at David Attenborough's 100th birthday. Happy birthday, Sir David. But in this show we always make space for a story that might have received fewer headlines than the birthday of Britain's. I'd say favourite person. I think it might be. Chavi, you are up this week. What have you got? So this is under the radar, a story that hasn't got the headlines. and as you may know I will give you a totally arbitrary bonus extra big piece of birthday cake if you can link it to David Attenborough. So I can link it actually to the fact that it under the radar not really to Sir David unfortunately because everything I can come up with a hundred is like dire and So I not even going to try I was in Nepal late last month and I was going to do a story on an early warning system that alerts people to landslides OK, and landslides are pretty common in the pool, right? Yes, yes, absolutely. Is that because of steep terrain and heavy rains? That's exactly it, Marnie. Every year, somewhere between 40 to 200 lives are lost because of landslides. And there's also cattle and structures, infrastructure. When I was traveling, I saw so many roads that had been reinforced because there'd been a landslide, or there were places where it was evident that there had been a landslide and it was still not really cleaned up from last year's monsoon. And in 2015 was the big one that everybody talks about. It was caused by a 7.8 magnitude earthquake and 250 people died. And it's a very, very big deal. Landslides are very important all over the world. But in Nepal, an early warning system could potentially save a lot of lives. And when you say early, how early are you talking? So I don't have that answer in hours. But in terms of notice, it's been enough that in many cases, people could even relocate their larger livestock and move them as well as the humans to a designated safe spot. Scientists at Tribhuvan University in Kathmandu started looking into it directly after the 2015 earthquake. And in 2018, they came up with a very local adaptation to landslide warning systems that are used elsewhere. And what they did is they basically melded together a bunch of different instruments and sensors, including an extensometer, which is something that records displacement and movement of the ground, plus a rainfall gauge and a vibration sensor and a soil moisture sensor and GPS. So all of these together put their inputs into a microcontroller, which acts like the system's brain, and then it's all wired to a threshold, which when it's crossed... Sets off some sort of alarm? hmm, exactly, a loud siren goes off. And in some places, an SMS appears on your phone. But there are three problems. One, big one, is that the sirens are not being maintained because funds have been diverted to other projects that are even more urgent. And then there is some early warning, but often it's not early enough. So things can change in a minute, right, if there's a cloud burst. And then even more concerning, there's new research published by the University of Melbourne scientists in Australia who found that the safe zones where people are evacuated to are sometimes on even more dangerous fault lines or terrain than the places that they are monitoring and need to be evacuated. And how did they figure that out? By accident, actually. So the University of Melbourne researchers got access to data from a European satellite, and this one bounces radar off the and it can map the terrain in really fine detail. The satellite, which is called Sentinel-1, just happened to fly over this part of Nepal in just the right way. And the images that it mapped happened to reach the lead scientist, mathematician Antoinette Tordesilas. And she was able to run AI through this data. And then she was able to tell the mayor the bad news, which is that the place everybody was being evacuated to, the designated safe spot, was actually not safe at all. But there was also good news because with this mapping, she was able to tell them that the high school was actually safe and they could change the place that people would be relocated to. And she was able to do this because they looked at the physics of how the slopes fail, along with all this amazing satellite data. So what now? So right now, the Australian team is collaborating with the same Nepal team that had deployed the earlier warning system with local modifications for the terrain. So they're using all of the on-ground sensors, as well as this new set of data from the satellites. And then they're overlaying all of it to make predictions on how much the slopes are changing and things like the fault lines. and then the pilot study will finish when the monsoons are over and they'll be able to find out how many lives they've saved. The previous system has actually saved more than 400 lives since it was deployed because they've been able to move people out of what were then really massive landslides. So they're hoping that during the monsoon this year, they'll be able to do even better. Thank you, Chavi, for a story that definitely was under the radar. Nepal's landslide early warning system. Good to hear that it's saved some lives already. And just a reminder to listeners that this is a David Attenborough themed episode of Unexpected Elements and you can email us on unexpected at bbc.co.uk and our WhatsApp number is plus 44 330 678 3080 or you can write to us I love a postcard and fun inside science fact did you know that if you want to get hold of David Attenborough you can't email him you have to send him an actual mailed letter and I have multiple colleagues who were like well what do we do what do we do panic panic how do we write a letter and they've got responses from him and they absolutely treasure their responses so that totally clocks yeah spreading joy if that appeal to the written words has moved you to write to us our address is unexpected elements bbc world service cardiff cf104ga in the UK. Of course, we love reading all of your emails and messages on this programme. And last week we asked if you had any stories or anecdotes about Sir David. And we also reached out to some people in the extensive BBC network for their stories. To start things off, we have a voice note from Helen Scales, a marine biologist, broadcaster and author. a few years ago I wrote a book about the royal institution Christmas lectures in particular the ones about the natural world so of course I had to include the 1973 lectures by David Attenborough and his series was about the language of animals so I watched back his lectures the film I wrote the book and I got in touch with David to see if he might be so kind as to write an introduction and was so thrilled when he said he would and in fact the note that he wrote for me is something of a confession and he says that essentially he tried to back out of doing the lectures. He wrote to the BBC to say he wanted to break his contract. The BBC did eventually persuade him to give the lectures and if you get a chance to watch them back you'll see they are really charming. The animals don't always do what he expects, the mice don't respond to the squeaks of their mother, the porcupine won't come out of the box without being lured with a trail of bananas. I think my favourite moment is when David comes out with a ring-tailed lemur in his arms. The lemur called Tammy and feeds him some grapes while he discusses how lemurs use stinky smells to communicate with each other. Luckily they don't do that actually in the room but it's just this really lovely interaction between David and Tammy there in front of the cameras. Yeah it's really gorgeous. So the reason Helen told us that he was unsure about doing these lectures is because they're televised live and he was worried about all the animals misbehaving. So, you know, they say never work with children or animals. And the absolute irony of this is that who was the person who made the decision that the annual lectures ought to be broadcast live? Yes, it was Sir David Attenborough back when he was controller of BBC Two. Real editor vibes there. Yeah. Now we've got another correspondence from Andrew Wilson, who's worked on the sound for wildlife documentaries. Oh, I know. For 40 years, including the iconic David Attenborough series, Blue Planet and Planet Earth. I think we were recording narrations for the original Blue Planet series. And he was coming down from London where he lives, but he was running a little bit late. and I was just waiting in reception with a cup of tea in my hand and I saw him coming down the road. So I opened the door to let him in. And just as he came through the door, there were a couple of students the other side of the road, a couple of young girls walking up towards the university. And they spotted him and went, oh, look, it's David Attenborough and sort of waved. And he turned and gave them a smile and a little wave back. And he came through the door and I said, why doesn't that ever happen to me? He looked at me like I was mad and he said, well, you've either got it or you haven't. And I thought, yeah, you have got it and I really haven't. Poor sound guy. Poor sound guy. Always just behind the scenes. But his sound is amazing. Isn't the music just always terrific? It's really, really lovely. So we've had a lovely email from listener John. Tristan, can you read this one? Sure. John writes, About 65 years later, I travelled to Komodo Island with my partner and her niece. They were born and brought up in Java, Indonesia. Perhaps Sir David had a much greater subliminal impact upon my life than I could have ever imagined all those years ago. Oh, that is lovely. If anyone is inspired to tell us any more anecdotes, then I've given out the details several times. But thank you to everyone that wrote in, including Randy in Rochester who gets a special mention because a couple of weeks ago we had a frog themed episode and he writes you talked about frogs and you asked listeners to send you letters from countries that have frog stamps well I just had to write I love to write and I have lots of stamps to use up oh wow he really used up a lot of stamps one two three four five six So the stamps on this letter include two ornate chorus frogs, a blue spotted salamander and an American kestrel. So full points to Randy. Do keep all of those emails, messages and letters coming in. Next up, do all animals see at the same speed? That's after this. Ella here and I'm back with the answer to the quiz. Earlier I asked you which of these species is not real. A. The dinosaur Tiankosaurus atumbori B. The flowering plant Serdavidea solanona C. The echidna Zoglossus atumbori And the answer is A. Tiankosaurus atumbori I made up the name of this one. There is, however, a herbivorous dinosaur called Tiankosaurus nedigo apophorema, which is a portmanteau of the surnames of the cast of Jurassic Park, one of which is Richard Attenborough, David's older brother. But worry not, David Attenborough does have a whole genus of dinosaurs named after him, marine reptiles from the early Jurassic epoch called Attenboroughsaurus. Well done if you got that right. And I really recommend checking out the other things named after David Attenborough. Our listeners don't just send in their emails and messages, they also send in questions. and being a helpful bunch we try to find them answers. It's time for Ask the Unexpected. And we have a question from Adam in London on a surprising variation in the natural world. I was recently researching some information on peregrine falcons and was surprised to learn they see at a different speed to us humans This was a new concept for me but did not realize there is a speed of sight My search results online indicated we humans have a range of seeing speed I wondered if you might be able to provide some light on the speed of sight. Do individuals have a fixed speed? Or does it vary? And what induces variance if so? Thank you for your question, Adam. So is there a frame rate, I guess, to how we see and why does that vary if it varies? Okay, to answer, we reached out to Dr. Clinton Harlem, who researches the speed of visual perception in humans and animals at Trinity College Dublin. And he began by telling us what exactly the speed of sight is. So speed of sight is basically how much visual information you can process over time. So usually we measure that in sort of frames per second. And that's kind of like how a computer monitor works. So it refreshes at a certain rate and our eyes do the same. So that all has to do with the brain and the neurons and how fast visual information gets sort of sent to the brain and how the brain then acts on that information. And it all has to do with how you live in your environment and how you have to interact with it. If you live in a very dynamic environment and you need to be very maneuverable and very fast, then of course you also need to be able to see very fast. So animals have a frame rate for processing visual information, which is affected by the way each experiences the world. Clinton told us that peregrine falcons can see two to three times faster than humans because they need to effortlessly track and catch fast moving prey. Their visual processing goes up to 129 frames per second, while ours sits at around 40 to 60 frames per second. So there is a range to human speed of sight as well. But what causes it? So it does vary. And there are a lot of things that can affect how fast we see. So when you think about all the external factors, they all have to do with what it exactly is that you're looking at. Are you looking at something very far away or close by? or is there a lot happening in this visual scene that you're looking at and are all these things moving or not? But also what color this specific thing is that you're looking at and whether you're looking at it in bright daylight or in the dark. And then on top of that is all our internal things that are happening as well. So if you're a little bit tired, for instance, then our nervous system tends to get a bit more sluggish. So we see a bit slower. And the same thing happens after you've had a couple of pints. but it also varies quite a bit from person to person. And there are certain diseases, especially things like things that affect the nervous system or brain damage that can all affect how fast you see. But there's also a lot of variation just in normal, healthy people. And generally that doesn't really mean much in day-to-day life. So we're still trying to figure out if seeing things at a certain rate actually means you're better at something, for instance, or not. one of the areas where you probably would see a difference is in these very, very elite level things where the selection pressures for the best performance and the best reaction times are really strong. Thank you to Clinton Harlem there. And thank you to Adam for your question. Listeners, if you have any questions and you'd like the Unexpected Elements team to have a stab at answering it. The email address is unexpected at bbc.co.uk or you can send us a message or a voice note to WhatsApp. It is plus 44 330 678 3080. So Sir David Attenborough turning 100 has not gone unnoticed by our colleagues over in news which is good because that means that we can pick the news peg of David Attenborough's 100th birthday for this entire show but it does mean that there's quite a lot of Attenborough related content on the airwaves at the moment and when I was listening to the radio earlier this week I caught a discussion of his influence on a group of wildlife documentary makers who'd worked with him and this was on a BBC World Service programme called Outside Source. So here's wildlife documentary maker Victoria Bromley. David has been a witness in his lifetime to the very quick change to where we've arrived at today. And as I say, he has a very deep understanding of that. But he, again, still has this approach of excitement, of curiosity. He's certainly not somebody who's afraid of new developments. He's very excited by technology and new approaches. And it's something that's also defined his career. he's seen what's possible. And wow, the changes that he must have seen over his century. And that was the big thing that struck me is what must he have seen, not just seen, but shared with us, highlighting the life cycles and the threats facing other species that share the planet with us. In wildlife conservation, animals get the lion's share of the attention, pardon the pun. But according to research that's out this week by the Royal Botanic Gardens Kew and the Zoological Society of London, the world's flowering plants are in serious trouble. So this report shows that just over a fifth of the evolutionary history of flowering plants or angiosperms at risk of extinction and that just under 10,000 species are considered edge species or species that we should prioritise for conservation. So that is one of the co-authors, Dr Felix Forrest, who I didn't even notice is a case of nominative determinism until my producer Alice pointed it out. Well done Alice. So Felix has calculated the genetically distinct plants, the ones called edge, and as he said, a fifth of them around the world are under threat. So why is that a problem? So edge species is a species that represents a lot of evolutionary history that is unique to it. It could be the sole representative of a fairly ancient lineage. But edge species is also a species that is threatened. So edge is two components. So it needs to be a species that is isolated on the tree of life and that is threatened. It's been shown that if we protect a certain proportion of evolutionary history, we've also increased the chances that we're protecting the various features of biodiversity. And among those features are the things that we as humans are using, like for food, for medicine, etc. So by protecting more of that evolutionary history, we increase the chances that we're protecting the plants that we use right now, but also the plant that we could be using in the future. For example, a plant that might have a cure for a particular cancer or a source of food that could alleviate malnutrition in parts of the world. So there's a lot to lose, but identifying the edge plants gives conservation scientists a list of priorities, what to focus on first. So what exactly is being saved though and where? Oh, everywhere. I mean, this is global efforts. So Mozambique, Mexico, Nepal, where you just were, Chavi. Mali, Philippines, India. I did ask Felix for his favourite tree and it's something that they only just discovered over a decade ago and it only grows on the top of mountains in the cloud forests of Honduras and genetically it's incredibly distinct. That's very cool. I know. Also on the list of edge plants they've got something called the titum arum which is a large i mean ridiculous like two meters tall plant that flowers once every five years and when it flowers it stinks like a corpse another one of the edge species is a plant called the wallamie pine and it's not only a conservation good news story, which is a rare treat. But it also brings us back to David Attenborough. Now, William e. pine is something that was known only from the fossil record up until the mid-1990s, when it was by chance rediscovered in the Blue Mountains of Australia. So it was a complete surprise to find that species still alive, because it was known only from the fossil record. so there was a big program to try to propagate them and distribute them across the world and one of the first one that was planted outside of australia was the one that was planted by david atembero and you can still find the specimens the beautiful specimens not too far from the orange reac queue and it's doing well and it's doing very well yeah those those trees are very happy in the uk so there you have it bbc manager wildlife presenter 100 year old and tree planter, another string to David Attenborough's bow there. Can I just finish up with another clip from wildlife director Victoria Bromley talking about why Attenborough is such an inspiration? What's so impressive is to think of all of his travels, all of his understanding of not just, you know, natural history, but also how our world has changed in the course of his lifetime. I think a lot of people, having seen the big changes, particularly since the 1950s and the impact that humans have had on our planet. It despair, but what's very inspiring about David is he probably has seen more of the world than anyone. He has a very comprehensive understanding of the state of the world, and yet he still has hope. That's a good note to end on. So what have we learnt over today's birthday celebrations for Sir David Attenborough? Well, we've learnt that 100-year-olds may have extra special proteins that have helped them reach a great old age, We've learned about the immortal jellyfish that can turn back into a juvenile. We've learned about tiny Antarctic plankton that may lock up more carbon than the Amazon. We've heard about Nepal's landslide safe zones that might not actually be that safe. And we've heard why a peregrine's eyesight is just faster and better than ours. Tristan, Chavi, out of all of that lot, any favourite facts from today? I think the speed of sight. It's just something I'd never thought about before. Tristan, any favorite fact from this week's show? It wasn't really a fact, but you know, Chauvi said that jellyfish cells never lock in their identity and that a nerve cell can become a hair cell. That image of the jellyfish with the bowl cut haircut has been definitely floating around in my head quite a bit. It's such a good image. like Beatles wigs in the sea floating around. Well, it's time to bring this party to a close. But before I go, I should thank my guests for turning up and being wonderful this week. I should also thank David Attenborough, even though, you know, he didn't come to this particular party. But this is part of, I'd say, a week-long celebration over different bits of the BBC. as Sir David Attenborough turns 100. But for now, in Mumbai, India, thank you, Chavi Sachdev. Maha Dunan, I'm so happy to be here. And in Helsinki, Finland, thank you, Tristan Ahton. Thanks for having me. Au baha. So, party bags for all. I'm Marnie Chesterton. The producer was Alice Lipscomb-Southwell with Ella Hubber and Robbie Wojciechowski. Do join us next week for more Unexpected Elements. The crew of NASA's Artemis II mission have returned home safely after successfully completing their groundbreaking voyage around the moon. Splashdown confirmed. Humans are back in the business of going to the moon. But while the mission is over, the Artemis space program is just getting started. 13 Minutes, the BBC Space Podcast is looking back on their epic journey and discovering what the future holds for the Artemis space program Just imagine what we as humans can do next 13 Minutes presents Artemis II from the BBC World Service Listen now, wherever you get your BBC podcasts