Nobel Prize Roundup
In the news, we dissect the achievements of the Nobel prize winners for science and medicine, ask whether paracetamol causes behavioural problems in children, and hear about the disturbance caused by cockatoos in Sydney's suburbs...
In this episode
00:55 - Nobel prize for Physics 2022
Nobel prize for Physics 2022
This week’s show falls during a very special week for the scientific community. That’s because it is that time of the year when the world celebrates the very best in research and discovery as the Nobel prizes for science and medicine are awarded in Sweden. We wanted to pay tribute to the work of these fantastic scientists, by explaining a little bit about the work the prize winners won for. The physics prize has been won for the subject that Einstein sceptically called, “spooky action at a distance.” James Tytko…
This year's Nobel prize for physics was awarded to Alain Aspect, John Clauser and Anton Zeilinger.
The official citation sets out the awarding of the prize “for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science.”
Let’s unpack this. Quantum theory is the branch of science that aims to solve the great cosmic questions that have captured the imagination of some of the most brilliant minds. It is the next frontier for scientists seeking to understand the fabric of the universe.
Yet despite the very big questions it endeavours to answer, quantum mechanics describes the behaviour of systems at the atomic scale and smaller. In the quantum world, matter has wave-like properties, in contrast to the more rigid and tangible view of the world posited by classical physics - that’s objects and phenomena we can observe with the naked eye - and set out by Isaac Newton.
Where our Nobel prize winners come in is in their work on a smaller aspect of the overall field of quantum mechanics: the branch called "quantum entanglement."
This is the idea that two particles, even separated by considerable distance, remain in touch with one another and even dictate the properties of the other.
One way to think about this is to imagine being given one of two balls. You are told that one of the balls is white and the other is black. So, by deduction, if you receive a white ball, you know the other ball is black.
But where this becomes interesting is that, in the quantum realm, until one of these particles - or balls - is examined, the properties of the other are not determined. So both balls are effectively grey until one of them is looked at. At that point, one turns white and the other black.
尽管这听起来令人难以置信,方面,条款and Zeilinger conducted the experiments to show that this phenomenon, theorised in the 1960s by Northern Irish physicist John Stewart Bell, is real. Though why it works, we have no idea. Even Einstein called it "spooky action at a distance".
Nevertheless, quantum entanglement could have many applications for use in the modern world: in quantum computing to help solve complex problems, and in encryption, useful for communications and banking.
Despite this breakthrough, there is much work still to be done in the field. From a theoretical point of view, a new Einstein is needed to blow our understanding of the nature of matter wide open. Progress like this, however, indicates that we’re on the right path...
04:29 - Does paracetamol cause behavioural problems?
Does paracetamol cause behavioural problems?
Kristin Sznajder, Penn State University
Paracetamol is the world's most popular painkiller, a crown it stole from Bayer's aspirin - the world's first trademarked drug - on safety and side effect grounds. It's also widely used - and regarded as safe - in pregnancy. But Penn State University's Kristin Sznajder has found a possible association between paracetamol use during a pregnancy and subsequent behavioural and sleep problems in children by age 3. There was a 20% increase in the risk...
Kristin - We had seen some literature coming out showing associations between using paracetamol or acetaminophen during pregnancy and problems with neuro behavioural child development.
Chris - And you wanted to find out whether it was a causal thing; does using this agent cause this to happen or might there be other factors that actually account for it?
Kristin - Absolutely. That's exactly what we were looking for. So one of the great things about our study is that it followed women from starting during their pregnancy through three years postpartum. So we were able to see what came first and we know that they're taking acetaminophen or paracetamol during pregnancy and to follow them to see how their children were at three years.
Chris - How many women did you follow up?
Kristin - We followed up over 2000 women.
Chris - And what were you asking them? Did you or did you not take paracetamol presumably, but how fine grained was the information?
Kristin - In their last trimester of pregnancy we asked everyone in the study what medications they were taking during their pregnancy, including vitamins. Also why they were taking the medication. So we were able to then look through the medications that they listed for each woman and see which medications had paracetamol in them or if they were just taking paracetamol alone.
Chris - Did you get some insights into how much they were using? So would someone tick the same box if they had one headache once and took one paracetamol versus someone who had really bad joint pain all through pregnancy and used it every week?
Kristin - We tried to get at that, but the data weren't very reliable. We actually have a new study underway that we're hoping to get better at the dosage and frequency of acetaminophen.
Chris - And when you crunched all the numbers, what was the relationship that emerged?
Kristin - We found an association between paracetamol use during pregnancy and attention problems and problems with sleep among children at three years old.
Chris - Was the effect strong or are we talking about it being just above chance.
Kristin - It's 1.2 times more likely. So I wouldn't say it's an extremely strong association, but the association was statistically significant.
Chris - And any clues as to who's vulnerable? Was this across the board or if you then begin to ask, are there certain groups in there for whom Mum takes a lot of paracetamol perhaps because she's got some other underlying condition and it's the other underlying condition that's causing this? Or were there other factors that could be discounted and you could say, no, look, this is purely because of exposure to paracetamol.
Kristin - I think one of the strengths of the study is that we were able to take into account those factors you mentioned. So because we asked why they took paracetamol or acetaminophen during pregnancy, we could then take that into account and we found this effect of acetaminophen as an independent effect. So it wasn't a fever or infection.
Chris - The other thing that is an important component of proving that something causes something else is it's got to be biologically plausible whereby you can say, well, we know how this thing affects the body, and if that happens, we can explain how that might translate into this outcome. So can you link a pregnant woman taking paracetamol and a child with neuro behavioural problems?
Kristin - Yeah, there has been research that shows paracetamol may disrupt cell development. So we think paracetamol could disrupt cell development and also results in placental damage.
Chris - When did paracetamol first begin to be used and when were we told it's quite safe to use this in pregnancy? Because it seems to me that we've got very good at diagnosing things like developmental disorders and behavioural problems in the modern era. There seems to be a lot more of it around now. Is that because we are better at diagnosing it? We're picking it up more, but it was always there. Or is there some kind of coincident onset of we're seeing more of these cases because there were more mums using paracetamol when they were pregnant?
Kristin - That's a fabulous question. I think we're really trying to disentangle that. I'm really not sure if we know the answer to that. I think we are getting better at diagnosing developmental delays, but I do think that we're still trying to figure it out. There could be several factors related to behavioural problems in childhood genetics and environmental exposures, possibly in utero. So we're really working to figure that out.
Chris - It's, as you say, critical though that we do, isn't it? Because this is one of the world's most popular painkillers regarded as one of the safest and very broadly used during pregnancy.
Kristin - Absolutely. This is something that really needs more focused research. Literature is emerging. There has been a call to action to reduce paracetamol use during pregnancy that came out last year and I think we're really showing these trends that people should be a little more cautious as they consider using paracetamol during pregnancy.
Chris - I do feel for pregnant women though, because they're frightened to do anything these days, aren't they? What should then a pregnant woman listening to this do if she has a headache?
Kristin - I think she should talk to her doctor to weigh the options and what she could do. Or maybe talk about what medications are safe with her clinician and maybe bring up some of these findings that we're talking about to see what her clinician thinks.
Chris - I think a lot of general practitioners are going to be confronted by patients walking in there with your paper and they can say, 'what do we do?'
Kristin - Well, maybe. It's the risks and benefits that people need to take into account.
11:03 - Nobel prize for Chemistry 2022
Nobel prize for Chemistry 2022
This year’s Nobel Prize in Chemistry has been awarded to Carolyn Bertozzi, Morten Meldal, and Barry Sharpless for their pioneering work in the field of “click” chemistry.
Conceptually, click chemistry is a bit like molecular Lego: it’s a way of stably snapping together the building blocks of molecules to efficiently construct bigger, more complex chemicals.
Imagine trying to assemble a complex piece of flatpack from Ikea: you have all the pieces, and you know what the end result should look like, but you don’t have enough pairs of hands to stop the thing wobbling all over the place while you add the next component. The result is that it falls apart faster than you can make it!
Click chemistry basically solves this problem by handing the builder a bunch of cable ties with which to hold the rights bit of his molecule together so it doesn’t fall apart during construction.
The result is that, broadly, if we know what molecule we want to make, now we can use click chemistry to create it, but without the lengthy reactions, wrong turns, or low efficiency of the past.
From chemical manufacturing and engineering, to the pharmaceutical industry, the potential of the technique is huge. And because the technique can also be water-based and made to work without resorting to harmful conditions or substances, it can even be applied inside living cells.
This was the breakthrough demonstrated by Carolyn Bertozzi.
She added a “click” chemical to cultured cells, which incorporated them into the sugars they produce internally; this enabled Bertozzi to hitch up coloured dyes to track how key sugar-containing molecules are moved and processed, and even how whole cells move and migrate.
This has helped subsequently to reveal how cancer cells sidestep our immune systems and spread, and led to techniques that mean we can target radiotherapy directly to tumours meaning healthy cells nearby are less likely to be harmed.
th贝尔托齐说,她完全惊呆了e call from Stockholm. Sharpless, though, is likely taking it in his stride: he’s won the Chemistry Nobel Prize once already. For him, presumably, chemistry just clicks...
13:23 - Recycling Polythene
Recycling Polythene
John Hartwig, UC Berkley
A new way to break down and recycle plastic has been announced by scientists in the US this week. This is welcome news since the world produces millions of tonnes of plastic every year, yet less than 20% of it is recycled. Most ends up in landfill, some is burned and a significant amount ends up in the ocean where it degrades into potentially harmful microplastics. Part of the problem with plastic is that it's an unnatural chemical, which nature has no easy way to attack, so it just hangs around. But John Hartwig and his colleagues have developed a relatively low temperature chemical process that can break into the long chains of carbon atoms that make up polythene - or polyethylene - and break them into short molecules of the gas "propene", which is a valuable raw material for making many other materials. He told me how it works...
John - Polyethylene is multiple units of ethylene put together through carbon/carbon bonds, which are very stable bonds. So what we've done is a three step process where first we introduce a change to the chain that provides kind of an Achilles' heel where we can then cleave that chain. And maybe a good analogy is if you think about the polymer chain being actually a physical chain like you'd buy at the hardware store that has these links that are very stable and you can't pull them apart. But if we make a chemical change to our polymer chain that transforms one of the linkages to say a clasp like you have on a necklace, that could then be opened. Now we have a way to break apart those chains under milder conditions. But then there's two additional steps to rearrange the change and attach a very small molecule to break those down into very, very small pieces.
Chris - I was going to ask how many of these so-called "clasps" one would need to insert in order to get this thing to fall apart? And under what sort of conditions do you need to do this? Because one of the criticisms of recycling processes is that, if you're not careful, you end up with a bigger carbon footprint than the one you're saving!
John - Right. Fewer than 1% of those chains need to be transformed into a clasp. That transformation of the chain to the clasp, we do that at 200 degrees, which is a pretty low temperature for chemical processes.
Chris - And how do you actually do this? What is the mechanism by which you change those chains so that you can then do this modification and make them fall apart?
约翰-第一步是一个叫做脱氢反应genation, where we remove hydrogen: therefore the name. We do that with a catalyst. The catalyst has platinum in it. It's a platinum zinc catalyst. That's the best one we've found. And then once that chain link has been turned into a clasp, we use two catalysts. One that is the subject of a Nobel Prize in 2005, Olefin metathesis catalyst it's called. And so that basically would take two chains that would have a clasp, undo the clasp, and put the chains back together. And then we have another reaction that would take that clasp. We walk that clasp bin just a little bit into the chain and then break the chain at that point to make a small piece off the end and a shorter chain. And then we do that about a thousand times to turn the solid polyethylene into a gas propene. That's our final product.
Chris - Is this a single reaction that you can do those three reactions in one place? Or do you have to do one thing, feed into the next, and then feed into the next? How practical is this?
John - Right. We actually run it as two. We run the de hydrogenation first and then this moving of the class. But opening and closing of it, those two reactions are run at the same time. There's also a very closely related work that has just appeared also in publication and they run it together, but the yields are lower than in our case. So in principle, all three steps could be run together and practice. Our highest yields come when we run them separately.
Chris - And what sorts of yields can you get? Is this a practical and viable, as in industry ready technique? Could we see this digesting plastic bags anytime soon?
John - Well, the answer to the last question is it will take a lot of time to develop, but the answer to the first question about the yields and whether it's practical, the yields are very high. Almost 90% gets converted into propene. And even on waste plastic, the yields are around 50% and they're probably higher because those plastics aren't all polyethylene. They contain fillers, colours, dyes and various other additives to them. But it takes decades between the time of a first paper like this and when it becomes practical. So we need to have the catalyst be very, very stable to be able to run for a long period of time, make many molecules of the product maybe a hundred thousand times. And right now we're at maybe a hundred instead of a hundred thousand. So we have a lot of development to do, but we hope this provides motivation to do the work and demonstration that it could become feasible in the future.
Chris - The problem plastic has at the moment - it is a wonderful material when we first make it and first use it - it becomes a pain when we get rid of it. It's valueless almost, isn't it? When it's a waste material. Does your process mean that potentially we return value to waste plastic? And does that solve our problem in the sense that it incentivizes people to pick it up?
John - Well, that's exactly the idea. So what we want to do is to take aims back apart to the small molecules like propene that has only three carbon atoms in it and is a feedstock chemical to make all sorts of other things. That's the idea of this kind of recycling, we call it chemical recycling or advanced recycling.
19:24 - Nobel prize for Physiology or Medicine 2022
Nobel prize for Physiology or Medicine 2022
This year’s nobel prize for medicine and physiology goes to Svante Pääbo, a Swedish geneticist, for completing the “seemingly impossible” task of sequencing the genome of our extinct relatives, the neanderthals.
But why was it deemed seemingly impossible? Well, for around the last 30,000 years, homo sapiens, which is to say us, have been the only species of hominid left on the planet, meaning any samples of neanderthal DNA, such as bones, would have undergone a lot of degradation. DNA is a resilient molecule but, just like any other, will fall apart given enough time. DNA loses half of its genetic content every 521 years, which meant that any useful material left in 100,000 year old samples would have been sparse at best. This also doesn’t even begin to cover the amount of bacterial contamination that the bones would have gone through in the past few millennia.
Recreating the neanderthal genome, then, would be the equivalent of trying to do a billion piece jigsaw, with a blurry reference picture, while most of the pieces are nearly identical. Small wonder, then, that the process took the best part of 20 years.
But, even against such fearful odds, he managed it. Along the way he created and refined several new techniques of repairing and sequencing DNA. He designed ‘clean rooms’ dedicated to handling ancient DNA, which protected his fossils from being contaminated by living humans. And advances in sequencing technology, aided in no small part by the Human Genome project, meant he could decipher the DNA found in ancient bones.
The findings of his work show that, up until 40,000 years ago, we were frequently mixing with neanderthals. Even after 1400 generations, up to 4% of our DNA can be traced back to them. In his own words, they still contribute to what we are today. This knowledge of our genetic makeup can have massive health implications, in fact a paper co-authored by Paabo concluded that the coronavirus caused more severe symptoms in people who had inherited a segment of Neanderthal DNA.. Knowing what we are made up of means we can more effectively understand how best to treat illnesses that have strong ties to our genes.
但相比之下,我们知道哪些部分摇来摇去m our ancestors can also show us what parts of us are unique to homo sapiens, and perhaps highlight what allowed us to become the success story we are today. In the words of Johannes Krause, a palaeogeneticist at the Max Planck Institute for Evolutionary Anthropology: “We’ve never come so close to understanding what makes humans humans.”
Make no bones about it then, Svante Pääbo is the deserved winner of this year's nobel prize for medicine and physiology.
23:01 - Could DART save the world?
Could DART save the world?
David Rothery, Open University
It's made a mint for Hollywood, but is the idea of nuking an incoming asteroid - to avoid an Earth impact that might otherwise wipe us all out - rooted more in reality than science fiction? Last week, NASA's DART mission slammed an impactor weighing half a tonne into a tiny moon orbiting an asteroid to see how practical the approach might be. They estimate, long term, that the collision might move the moon about 1% closer to the asteroid. Now the dust has settled, Open University planetary geologist David Rothery has been taking a look at the aftermath for us...
大卫-飞镖在一年前推出了先wn as a near earth asteroid, called Didymos, which has an even smaller moon. The moon's called Dimorphos. It's 170 metres in diameter. Didymos is about 800 metres diameter. It was deliberately crashed into the moon of Didymos to see what change could be made to the orbit of Dimorphos. The point is, in the future, we might want to change an asteroid's trajectory if it's heading towards the Earth. So this was an asteroid redirection test tried out on a moon because when you've got a moon in the regular orbit, it's easy to see what's happened to the trajectory. You can just measure the orbital period of a moon, see how that's changed by the impact. And there was this almighty collision and the plume thrown up from this collision was seen by telescopes tracking it from the Earth and also seen by a little CubeSat which the DART probe released a few days before impact, which was filming from space and saw the impact as well. And the way the ejecta has been flung out is intriguing people. It's come out in streamers rather than a continuous cone. So that's interesting. But that main science that's going to come from this is how has this asteroid moon been disturbed in its trajectory?
Chris - We don't think, though, that there are any objects which are on an Earthbound collision course at the moment do we? I mean, just to kind of calm people down, this is not because NASA knows something?
David - There are no dinosaur-killers lurking out there! There's nothing that's going to disturb global climate for a decade. But if one of these things hits the ground in a city, it will destroy that city. So you don't want it to happen. So we do want to know how to deflect these things away if we know that there's one coming. And the idea would be to get it several years - several orbital paths - before it's going to hit the Earth, because you only need to disturb the trajectory just a little bit so it misses rather than hitting. So the longer in advance we can do this, the better. But what we weren't sure is, if you slam into an asteroid, is it going to fall apart? The surface of Dimorphos is just made up of massive interlocking very large boulders and I guess smaller stuff in between. Now it's a rubble pile. Was it going to fly apart or was it going to stick together and the whole thing be disturbed in its trajectory as a single mass. It seems that the latter has happened, which is good news. It wasn't blasted into smithereens.
Chris - Because that matters, doesn't it? Otherwise you turn one threat into a thousand threats.
David - Absolutely, yeah. And it's good that that doesn't seem to have happened in this case.
Chris - Are they going to go back and have another look or will all of the observations now be from Earth?
大卫——仍然有数据从LICI回来ACube, which is the Italian CubeSat that was deployed by DART itself. But there is a follow up mission as well. It's called HERO. It's a European Space Agency mission, which we launched in 2024 and two years later will arrive. It will be able to see the crater formed on Dimorphos by the impact. And I guess it may refine the orbital period of, and the shape of, the orbit of Dimorphos around Didymos. But we will have that from ground based observations as well. By measuring the orbital period, which you can tell from the Earth, we know how much the moon's trajectory has been disturbed by this impact. But the follow-up from here will add another layer of information into that. So it's going to be a well studied system. They're both interesting shapes. They're both made of rubble, so in their own right they're interesting objects as well.
Chris - And does the planetary geologist in you want to know more about what these objects were made of? Because obviously doing things like this does expose to us what they're made of and they're intriguing things because they date from the very same material that formed the solar system four and a half billion years ago.
David - So I don't know how primitive this object is in terms of what processing has gone on. Some of these asteroids have been damp in the past and water has migrated through them and altered the minerals. It's too faint probably to have a very good spectrum of it. I'm speaking outside my sphere of knowledge now, but, looking at the pictures, the jagged rocks of all sizes on the surface probably give it quite a bit of cohesive strength. What's gone on to process this material so it's just a rubble pile intrigues me. And yet it's a pile of rubble which seems to have hung together pretty well under this sudden impact. If you hit this thing slowly, it might break apart. If you did it fast, the shock of the impact will tend to make these interlocking pieces hold together better. So if you want to deflect an asteroid, you've got to do it at the right speed as well. So there's a lot to learn about how to deflect asteroids. This was just the first well controlled step towards doing that.
28:47 - On the origin of limbs
On the origin of limbs
Phil Donoghue, University of Bristol
The evolution of animal limbs is a subject that has perplexed palaeontologists for a long time. Fossilisation is a very rare occurrence - less than 0.1% of all species ever to have lived have become fossilised, and so finding missing links in evolutionary biology is very difficult. This was the case for the origins of limb development, until very recently. Galeaspida are an extinct group of jawless fish, dating back as far as 430 million years ago. But, until recently, only their heads have ever been preserved. I spoke with Phil Donoghue, from the University of Bristol, about this new galeaspid discovery, which sheds light on the moment that these early fish developed the paired fins that may have led to our own arms and legs.
Phil - The real frustration, despite having tens of thousands of these fossils, is that all we've had until now are their heads. And the discovery that we've made now is a series of specimens of galeaspids, which preserve the rest of the body, providing us with insights into how the rest of the body plan of jawed vertebrates evolved.
Will - From what I've seen of it, it is a striking looking specimen, this fossil. But for the benefit of our audio listeners, what does it look like?
Phil - Well, it's a beautiful fossil, but beauty is in the eye of the beholder. It's basically a dead fish, and it's preserved at least as we see it, with the bottom of the body facing upwards. And it's fairly squashed. But the amazing thing is that it has a series of paired fins that extend vertically, almost entirely three dimensionally extending up from the body. It's the kind of preservation you never see in fossils of this type. And these fins extend all the way from the back of the head all the way to the tip of the tail in a way that we don't see in any living vertebrate and indeed any fossil vertebrate until now.
Will - And how did you come about this fossil?
Phil - Luckily, I had a graduate student about a decade ago with whom I started working on galeaspids. He's since gone back to China, and he and his colleagues made these amazing discoveries and were generous enough to invite me and to help describe them and interpret them.
——当你看见了,给了你什么that this fossil, this galeaspid, was the one that you were looking for?
Phil - Well, it was easy, really. It wasn't just a head. There was another three quarters of a body extending from the back of the head. And it had anatomical features, which we really didn't know that galeaspids possessed. And the key thing are these fins, really. All jawed vertebrates have a pair, unless they've lost them, a pair of anterior appendages, whether they're fins or whether they're limbs, and a pair of posterior appendages, again whether they're fins or whether they're limbs like our legs, and they're set entirely separate from each other. But in this galeaspid, which is probably the first vertebra to have paired appendages, they extend all the way, as I say, from the back of the skull all the way through to the tip of the tail. And what this suggests is that this is the precondition from which separate fins and limbs ultimately evolved.
Will - And whilst this might sound like a bit of an obvious question, why do you think they evolved the first limbs? What was the evolutionary advantage to it?
Phil - Well, the evolutionary advantage seems to have been if you extend from a cylindrical body, if you extend paired structures out, they appear to just generate lift. They allow you to effectively swim without putting any energy into the system whatsoever. It's just a product of the geometry of your body. The fins that these organisms possess weren't muscular. They couldn't move in any way, like the fins of all living, vertebrates and limbs,of all living vertebrates. That's a phenomenon that evolved seemingly much later in vertebrate evolution. But nevertheless, it's this precondition, this is adaptive benefit of being able to locomote without expending any energy seems to be the reason for why paired appendages first evolved.
Will - And how does this discovery change our preconceived timeline of appendage development?
Phil - So previously, again, based on fossils, if you set aside our new evidence from galeaspids, it seems quite clear that a more advanced group called the osteostraci, they just have seemingly just paired equivalent of our arms. So a pair of anterior fins. And these were flexible and these were muscular. And so we don't really see the equivalent of pelvic appendages, the equivalents of our legs until the origin of jawed vertebrates. So all of the evidence coming from developmental biology trying to understand the developmental basis of how fins and limbs have evolved, has been interpreted within this framework from the fossil record, suggesting that pectoral fins evolved first and pelvics evolved later. But the evidence from galeaspids suggests that actually, no, that's not the case. These are just peculiar conditions of derived osteostraci, for instance. And the condition in galeaspids suggest that the primitive state in which is one in which you have continuous fins extending from a pectoral through the pelvic position all the way to the tip of the tail. And it's actually the separation of that continuous zone of competence for developing fins that the differentiated anterior and posterior paired fins ultimately evolved.
34:11 - Mitochondria gene trade
Mitochondria gene trade
Patrick Chinnery, University of Cambridge
Cambridge scientists have discovered something surprising is going on in our cells that we’d overlooked for years. Structures called mitochondria - which used to be bacteria before they merged with our ancestors’ cells billions of years ago in a partnership that now supplies us with the energy that keeps us alive - contain their own bacteria-like DNA, separate from our main cellular genome. But Patrick Chinnery has discovered that pieces of mitochondrial genetic code periodically cut and paste themselves into our chromosomes; and this is especially true in cancers, which might explain some of the growth and resilience characteristics that cancers display.
Patrick - We got the first clue a few years ago when a group in the United States reported the transmission of mitochondrial DNA from fathers to children. This was a crazy suggestion to the field. So we went looking for an alternative explanation, and what we found was that it wasn't the mitochondrial DNA that was coming from the father, it was the nuclear dna. But what had happened is bits of the mitochondrial DNA had gone into the father's nuclear dna.
Chris - We should clarify the mitochondria, which are these cell powerhouses are in the cell, therefore they're in the egg cell that gives rise to an individual. They're not in the sperm. They're not transmitted from the sperm, which is why you're saying there's that distinction. You get your mitochondria from your mum, not from your dad.
Patrick - From our mum. They thought it was coming from the dad. We've shown it's not the case.
Chris - How did you prove that that was what was going on?
帕特里克-所以我们在基因组学与同事合作England who've been carrying out the hundred thousand genomes project. People across the whole of the NHS have been contributing samples to this, and we looked at the genomic sequence of over 60,000 individuals and 12,000 cancers and looked for the signature of these bits of mitochondrial DNA across all of these individuals.
Chris - How is it getting from the mitochondria, which has got its own little circle of DNA inside these structures inside our cells, and it's getting from a totally different part of the cell into the nucleus, the headquarters of the cell, and into a chromosome in there. How is that happening?
Patrick - It's a very good question and we don't know the answer to. We're embarking on a programme to work that out. We think what's happening is that as the mitochondria recycle, bits leak out and cross into the nucleus through holes in the membrane that surround the nucleus itself and integrates them into the chromosomes, which is how the nuclear genomes packaged.
Chris - The mitochondrial DNA has got instructions in it that keep those cellular powerhouses happy. It it's how they operate. What's the consequence of pasting bits of those genetic instructions into the main chromosomes in our cell? Is there one?
Patrick - It all goes back to how mitochondria originated and the idea was when they first came into the cell, they passed on certain functions to the cell. To do that they passed DNA. So actually what we're seeing now is a consequence of that process. All of this was thought to happen billions of years ago, but actually we've measured it happening in families and, in one in 4,000 families, a new bit of mitochondrial DNA goes into the child. It's never been seen before at that rate. And in cancers it's even faster.
Chris - What about the reverse direction?
帕特里克-它不会发生,有几个reasons why that might be the case. One is that you've got many, many more copies of mitochondrial DNA in Excel than the nucleus. The other is that there are holes in the nucleus that allow mitochondrial DNA to go in, but not the other way around.
Chris - Right. Okay. So it is a one way street and the consequences of this stuff going in, you mentioned cancer, and it does appear to occur more frequently in cancer cells when you look. Now, is that just a hallmark of the fact that cancer is a genetic disease and therefore a genetically unstable cell? It's more susceptible to this happening or is there more to it than that?
Patrick - We've looked at where these stick in the nuclear genome and looked at the pattern of that. And what we found is that they sit nearby breaks in the genetic code. So anything that causes your genetic code to break up will attract these, bits of mitochondrial DNA that effectively behave like bandaids in the short term to repair the genetic code. So in cancer you get a very unstable nuclear genetic code and one consequence of that is the mitochondrial DNA can find its way in there.
Chris - Could it endow the cell that's cancerous with enhanced properties to be even nastier?
Patrick - It could, and we found rare examples where, in actual fact, the inserted mitochondrial DNA probably caused a cancer by disrupting a gene that's protective against cancer.
Chris - The reason for asking that, I spoke to someone recently who published a paper in the journal eLife where they said, 'well, when you look at a cancer, it's under enormous pressure. The cells are being squeezed and squashed all the time. And if you look at the effect of being squeezed and squashed on the cells, it seems to make them tougher.' And they've built experiments where they're saying, 'what doesn't kill you makes you stronger.' And it's quite literally the case with these cancers. If they squeeze the cells, they get nastier. They're more resilient, they're more robust, they're more likely to spread around the body. They also said they're more likely to have the nuclear membrane that holds all the chromosomes in break apart temporarily under those circumstances. So do you think then, I'm just speculating here, what they're seeing is a product of being likely to spew out bits of genetic material all over the place and make the process you've seen happen.
Patrick - Could well be. We don't know whether or not this is hitchhiking on the back of something that happened before the cancer formed or whether the actual cancer mechanism is leading it to happen more often.
Chris - And just briefly then, Patrick, can we turn the tables on this and if we know this is happening, we know that these things are a bandaid for cancer cells, can we unstick that bandaid and use it as an Achilles heel for cancer?
Patrick - Good question. That's for future research, Chris.
Chris - So you don't know. Interesting, though, he didn't answer the question, which means you probably already have a research project I'd say on that. Is that true?
Patrick - Possibly
38:24 - Cockatoos become bin raiding menace
Cockatoos become bin raiding menace
Barbara Klump, Max Plank Institute of Animal Behaviour
The suburbs of Sydney are playing host to an unlikely battle of wits. Residents putting their bins out for collection have found themselves confronted by hungry cockatoos eager to open up the bins and help themselves to the leftovers. To deter bin-raiding, locals are resorting to increasingly complicated ways to safeguard their trash, but the indefatigable cockatoos are just working out how to get around them, and teaching each other into the bargain! Cockatoos are one of the most intelligent bird species and can copy an action after viewing it only once. Indeed their bin raiding antics have spread through the suburbs so quickly that now commercially-available cockatoo locks are doing a roaring retail trade! Will Tingle spoke with Barbara Klump, from the Max Planck Institute of Animal Behaviour who’s been following the arms race, on both sides: people sharing defense ideas, and birds sharing plans of attack…
Barbara - Over time more people protect their bins but also more people escalate the method they're using from more low level protection to higher levels of protection. This was in direct response to the cocaktoos solving some of the methods. So we think that this might be the beginning of what we call like an innovations arms race where one species changes the behaviour in response to what the other species is doing.
Will - There have been cases of arms races between two species in the natural world. You've got your bats and your moths, you've got your netws and your garter snakes. But these cases are more arms race based on evolutionary adaptations and physiological changes. So is this the first case that we've seen of an arms race based on behavioural changes?
Barbara - So I don't know whether it's the first case of a behavioural arms race, but it's certainly the best documented I would say. Because when we look through the literature, we were actually quite surprised how little there was. So there's mention that it might be happening between killer whales and their prey. And then of course lots of like anecdotal observations where people have told me they have like their personal arms races with the squirrels that try to get into their bird feeders. There is definitely this interaction happening, but I think it hasn't been studied in detail so far. But I think it would be very interesting to study this in other species as well because as you say, most arms races that we know of are on these like really large evolutionary time scales, but with like behavioural or innovations, arms races, this happens much, much faster. And that allows us to also like study it in much more detail. And I think it could be a really fruitful like future research avenue.
将——你看到胡的军备竞赛吗mans are gonna be involved in in terms of wildlife interactions changing in the future?
Barbara - I could imagine that it will increase just because cities expand and we will share more and more of our space with wild animals. So that naturally also increases the chances for human wildlife conflict, but it also increases the chances where such arms races can develop and then can be observed and studied. So I would imagine that it will increase in the future.
Will - And how do you see this one ending? Do you think cockatoos are going to win or do you think humans have managed to lock them out?
Barbara - That's a very interesting question and I don't know. So currently we know that the cockatoos can open some, but not all, of the protection devices that people have come up with. But that doesn't mean that they won't learn to defeat them in the future. And I think there's so many other factors that play into this arms race as well that, yeah, make it quite difficult to make a prediction. But I can tell you that I'm super excited to find out in the future.
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