Dawkins re-examined: Dawkins' legacy

good morning everybody lovely to see you all um we are here to discuss the gene machine my name is Ganesh Taylor I'm your host and I'm not going to be doing very much because of these two gentlemen on either side of me so with no further Ado dawkins's selfish Gene has been hugely influential both within evolutionary biology and The Wider public sphere it is a beautiful simple story that genes and not organisms Drive evolutionary change but critics argue the story is simplistic the effect of a gene is not always the same and is dependent on its host and the cell environment Dennis Noble a pioneer of systems bio biology goes further arguing that the organism and not genes are in fact in charge so Dennis as you probably already know anyway is a is a world-renowned biologist and professor emeritus of cardiovascular physiology at the University of Oxford he's famous for developing the first ever mathematical model of cardiac cells in 1960 his most groundbreaking book the music of life was the first work in the field of systems biology to my left of course is Richard Dawkins who is a biologist and best-selling author he is one of the most famous scientists in the world but you don't need me to tell you that anyway with good reason his 1976 work the selfish Gene was the first ever real Blockbuster Popular Science book shaping how we have all understood Evolution and where we come from and since then of course he's written numerous other bestsellers including the blind watchmaker The God Delusion and climbing Mount improbable so I'm going to sit back and let you two take it away I I approach this with some trepidation because um Dennis Noble was actually my doctoral examiner Richard we're in the chair again so I'm somewhat nervous I hope I pass today um I would like to ask you to ignore all that was said about the selfish Gene to me the argument today is about one paragraph in Dennis's excellent book dance to the tune of life which is a wonderful book um except that it's wrong [Laughter] um the the sentence well the paragraph concerned is is this book will show that there are no genes for anything living organisms have functions which use genes to make the molecules they need genes are used they are not active causes now I think that's a wonderful sentence because although it's wrong it's clear it's absolutely clear and open and articulate and that makes my job relatively easy um because I want to show the exact opposite is true um the truth is is opposite genes use individuals use organisms as tools for their own propagation if Dennis is right then I've been wrong for 50 years and so have actually most of the people now working in the field um studying animals in Africa and where the the kind of assumption is that organisms are working to propagate the genes that uh that drive them now I'm I'm not saying for a moment that other things in the organism are unimportant the the rhetoric of Dennis's book I think is wonderful I mean it's it's a it's a beautiful evocation of the um the unity of the organism the fact that all the parts are working together as a system um what is wrong however is the view that genes are used in a way he's implying that when this cell needs to make a protein it goes into the nucleus and consults the library which is the genome and takes down the volume relevant to the enzyme that's needed absolutely and this is the this is the one we need we need to make this protein let's get the relevant Gene out and use it um that that that is Dennis's view he's nodding vigorously um and um absolutely I have no problem with that as a physiologist and this is a physiologist I was an embryologist for that matter that is indeed what happens but as an evolutionist what matters is that genes are causal agents contradicting Dennis's statement um they are not active causes they are active causes in the following well she has a better shut up and let should I sort of um how how do we ever recognize a Cause well I think the answer is this we do an experiment we manipulate you cannot show that something's a cause unless you manipulate and it's a very trivial example suppose you have a hypothesis that a crows every time a church clock um told So You observe a correlation that the the the clock tolls and the and the crows uh is that is is it causal the only way to be sure is to do an experiment climb up into the Clock Tower and change the clock or manipulate the clock ideally make the clock toll at random and then if the crows uh then you've shown a causal link in the case of genes we know that if you if you mutate a gene then it will change the phenotype more importantly for an evolutionist that change Will Go On to the Next Generation and the next and the next and the next and potentially forever um whereas if you change anything else no matter how important it may be causally in the embryology of the animal if you break a leg circumcise a penis do anything else it will not be transmitted into future generations and that's the crucial difference genes are causal in the sense that a change in a gene a mutation has a statistical consequence in in an indefinite number of future Generations now the reason that matters is that natural selection chooses between Alternatives and the choice between Alternatives only matters if it is potentially Immortal or at least if it goes on for a very large number of generations darwinian Theory which Dennis has a lot of criticism of in his in his book is a theory of differential survival of genes in gene pools and that only matters if the genes are potentially able to survive in the gene pool for a very long time the ones that do survive are the ones that are that have a beneficial causal influence on everybody in which they find themselves successive Generations the genes find themselves in bodies again and again the ones that have survived over many generations will be the ones that have a causal influence on a long succession of bodies and now shut up amazing yes well I I love that introduction Richard because 30 years ago I did precisely that experiment let's go through it carefully because I think the experiment is important and this was work done with my colleague from Italy daru di Francesco and what we discovered in that work about 30 years ago was that a particular protein and therefore the gene it's an hcn protein so it's an hcn Gene that was responsible for the great majority of the cardiac Rhythm actually can be knocked out all the protein blocked and hardly any change in rhythm now I'll tell you something else that I think is very important to this debate that's what the great majority of genome sequencing and genome Association Studies have shown the association levels between the Crow and the the Bell or whatever it was I've forgotten now and the association levels are actually generally with a few outlier genes that are very clearly terribly important to the organism they can be overridden by the rest of the organism you see and that's exactly what was happening in our cardiac pacemaker work what we showed is the the Rhythm goes like that that's what's happening in your heart now and it goes with a particular frequency let's give it 80 80 beats per minute you block this particular component which we know as a matter of physiology contributes 80 percent of the rhythm-generating electric current you knock it out there's hardly any change in frequency can see now I think what is happening is that organisms are terribly robust they know how to manage with whatever genes they happen to have so what I think is happening there is simply that another network is operating when actually we've identified that Network too so we've done all of those experiments already and I think the genome-wide association study people have done this endlessly During the period in which for what is it now about 20 years of genome sequencing and what we find is that the actual Association levels are quite low and that I think is also important as a practical consequence because that's the reason why we don't have all the medications that were promised when the first human genome sequence was announced in great fanfares on both sides of the Atlantic in around 2000 with great nature paper of 2001 and that takes me on to another thing that I'd like to put to Richard which is this I think the evidence that as you put it the organism has gone in and changed its genes is evident in that 2001 nature paper on the human genome sequencing if you will want to look it up on your mobile phones it's figure 42. and what figure 42 shows is very interesting indeed they looked at the sequences for two major groups of proteins the chromatins and and transcription factors and what they found was astonishing when you look at the domains obviously you can look at it either as a genome sequence or as protein domains that are coded for by those genome sequences what you find is that whole domains have been pulled apart and put back together and slowly as an accretion of these domains now I think you Richard did the best calculation on this many years ago I think it was in was the watchmaker the watchmaker blind um very good book incidentally I full of Praise of your writing too and the you did the calculations that show how improbable it would be that for example the sentence me thinks it is like a weasel would arise by pure charms and what you think you I think you did there was to show beautifully with the mathematical model that if you held the various bits that had been shown to be correct you would get there very quickly and I think that's what organisms have been do with their genes you see I think they do go in I think later on in the discussion I'll explain the mechanism by which they do exactly what you're asking for how do they go in to the nucleus and tell the nucleus what to do I loved the way you put that Richie you see so I think you were absolutely right but probably for the wrong reasons yes well now Dennis you're talking about something very interesting which is the robustness of this organisms and the ability to um as it will manipulate and change things um and that is a wonderful fact from an embryological point of view from an epigenetic point of view um but nevertheless in the long run as an evolutionist in the long run as the generations go by no matter how clever even if organisms do do change what effect genes have and I'm sure they do nevertheless in the long run what matters is changes in gene frequencies in populations and I'm talking as an evolutionist now not as a physiologist or as an embryologist perhaps we could say that genes do two quite different things in embryology what they do is influence phenotypes in highly complicated ways including the ways you've just enunciated but for an evolutionary point of view what matters is the ones that are still here Ten Thousand Years hence you actually use the the rather rather Vivid um image I think you said somewhere yes 10 000 years to keep a genome that's right if you were to put a genome but somebody put Dennis's genome in a Petri dish that's right yes um and and keep it um going for for ten thousand years well it wouldn't keep going it would Decay as you as you rightly say however the information it could be preserved on paper you could actually write it down on a on a in a book on a you could carve the ATC and G um codons in Granite and and keep it for 10 000 years and then in 10 000 years type it into a sequencing machine which we already have and it would recreate an identical twin of Dennis Noble no I don't think it would you don't think it would no no uh why not well it would he would need one it would need an egg cell oh of course it would yeah yes yes I think we need in in ten thousand years they will they will have the technology oh I see okay and I now definitely need to follow up on a a different issue there and if I may Richard yes um because you see what it would need to be is a good self-replicator and you won't be surprised that I disagree with you on self-replication because I think that's a central feature because I think without the self-replicator I'm not quite sure that I understand what the selfish Gene idea really means now let me just explain briefly why it can't be a self-replicator the the way in which that arose goes way back to the quantum mechanics Pioneer uh in Schrodinger who in 1942 gave lectures in uh the university what not the university the Institute of advanced studies in Dublin he published it and what he said in that book is very insightful it was that whatever the genetic material was with his DNA protein or whatever it would be found to be a highly accurately reproduced molecular sequence and he called that an aperiodic Crystal the word crystal matters there because you see what you say Richard in your books is that it replicates much as Crystal does now I think that's partly true but unfortunately not sufficiently true is what exactly happens let's just go through it and there's got to be technical for about 20 seconds or so um what actually happens is as we all know the double helix discovered by Watson and Crick and Rosalind Franklin you remember those images that were produced I I see all the women and a few men clapping yes anyway what Rosalind was working on very interesting fact was not a crystal her work in that critical working out of the double helix was actually on the flexible thread that actually is the DNA in a Cell you can crystallize DNA that was done much later but not in a living cell otherwise you can never read it now why is the crystal metaphor accurate to some degree but not to sufficient degree and it's worth just going through the figures because they're very important what happens is the double helix unwinds is a c finds its mate because it naturally likes the other one that it likes to come in and link to it and the same applies to the T and and the G and so on so every one of them has a mate that's fine now that is a pure chemistry thing and you could say that's almost like a crystal forming itself because what crystals do is that the other molecules that are in solution like to in a lock and key fashion go into the crystal that's all fine so in the same kind of way and I think this is the reason why people like Richard say it is a self-replicator and rely on the molecular biology to say that they're quite right up to a point now the question is up to what point in all chemical reactions there's an energy a formation and breakage and from that you know how frequently it will go wrong it's about in the case of the nucleotides it's about one in ten thousand nucleotides now you might think that's fine if you wrote a scientific article of 10 000 words and you had only one word as a typo you would be very pleased but the trouble is that suffices for small viruses like Coronavirus because as a mutation rate of one in ten thousand each time it's copied would be acceptable if you've only got say 10 or 20 or 30 000 as a genome length we have got three billion and the difference is around a million fold now how accurate is DNA replication obviously that first stage which is Crystal like and I accept the metaphor there is accurate up to about one in ten to the four what is the accuracy when the cell actually divides and provides two new cells it's one in ten to the ten hardly a single that's rather like a proofreader of 10 000 books going through ten thousand books and making sure there's not a single error in the whole ten thousand books how is that achieved it's utterly amazing it's achieved by the living cell because what then happens as the problem of the breakages as we might call them in the DNA formation from the double helix and it's Unwound what then happens is the whole Army of enzymes go in and literally proofread the mistakes and I only know and that's why I say you'd have to put my genome in 10 000 years hence in into a living cell to do it now the question is which living cell and because you see that will provide all the material initially to enable it to be reproduced so what I'm saying is that it cannot be a faithful replicator except in the presence of its vehicle which is the living cell so I don't think there can be a need separation between the replicator and the vehicle proofreading is of course very important and that that is one of the ways in which true that self-replication happens what matters from an evolutionary point of view is that certain genes survive in the gene pool and others don't now the proofreading is very important that helps the thing along but what matters from The evolutionary point of view is the survival or non-survival in the gene pool of successful genes versus unsuccessful genes successful genes are the ones which statistically have a positive effect on their own Survival through Gene pools and the way they do that is via their phenotypic effects their effects Upon A succession of bodies in any particular body we have a combination of good genes and bad genes successful and unsuccessful and the body will die or not depending upon all sorts of factors that may get struck by lightning it may be eaten by a lion and wasn't looked looking and so on but on average if a gene is successful that what that means is that it has a beneficial effect upon a large number of bodies in which it in which it finds itself very often it will find itself in the company of bad genes and it'll die anyway but statistically on average certain genes will get through the 10 000 year time of the of more than ten thousand years millions of years will get through uh all those Generations because of its average statistical effect upon a whole lot of bodies and others will not get through because of their average statistical effect upon a whole lot of bodies that is natural selection that is why animals are so good at what they do it's why birds are so good at flying it's why moles are so good at digging it's why fish are so good at swimming it's because of the average statistical effects of a whole lot of genes working together in concert with one another to make good phenotypes and so all the complications of what's going on inside the body in embryology all the proofreading all the interactions all the things that Dennis described so wonderfully in his book are completely irrelevant if what you care about is the survival over many generations of certain genes rather than rather than other genes yes I I fully understand what you're saying Richard but I don't think you really answered my point because you see I was saying that none of that would happen without the cooperation at the least and I would say the very active cooperation of the living cell because as I said it's only a living cell that can reproduce accurately yes now I think what what we need to do here is to get another element into this because I think what you're really worried about is how can it be that the body can actually change the genome and that's the big question now the reason we know that it can is that we know it controls it that's the first step so let's see first of all how that can be done I have two very important colleagues have done the work I'm going to describe so I'm going to credit them dick Chen worked with me as a graduate student way back in the 1960s and is now working at the New York University of New York and um has done part of the experiments I'm going to describe an event for wreck who is a physiologist in the same Department as me in Oxford and what they've done is absolutely beautiful they've asked the question you see it's the relevant question that I think Richard is asking how can it be that the surface of the body or of a cell it might be that it's a unicellular organism then it would be the surface of the organism how can it know how can its nucleus know that there is a need to change and we now know how that can be done what they've shown is best described by imagining first of all that a single nucleotide is about the size of my fist and it said it's situated in the nucleus let's put that in the center of the cell if we did that on that scale the surface membrane of that cell would be way up in Scotland how on Earth can it be that a signal through a receptor on the surface can influence the nucleus and we now know how that can be done what they both found during different experiments in different cells was that calcium coming through protein channels in that surface membrane using the same metaphor way way up up there in Scotland creates a calcium concentration in a small Subspace underneath the membrane and that high calcium triggers a chemical reaction that produces a messenger and that messenger gets attached to some extremely important proteins in the cell those proteins are called tubulins and the name suggests what they do they form tubes literally they're a tube trains in cells and I'm not joking because what happens is those tubulins run all the way through from one edge of the cell to another they have little motors on them little molecular Motors and they can attach a messenger molecule to the motor and what then happens is phenomenal they literally walk along the tubulin it takes just a few seconds to go from that surface imagine on this scale way up there in Scotland to the nucleus what does it do in those experiments it changes the gene expression levels in the relevant genes that matter for that particular function now the only thing that's missing here and I'm sure Richard will pick this up very quickly so I'll say it myself is that those are very recent experiments done in 2016 and more recently 2018 I think it was anyway the important point is that we don't yet know how that induces genome change and I really mean actual change in DNA and yet we know also that those processes must be able to do that because we can show that let's take a tumor developing your body and it's a bad situation you're beginning to get metastasis so the doctors get out the radiotherapy and the chemotherapy they attack it and try to destroy it what happens the tumor cells themselves tell the genome to increase the mutation rate how can they do that precisely by the kinds of mechanisms I've just described because the mutation rate is under the control of what is happening in the body as a whole what then happens is phenomenal it happens in your immune system all the time it happens in bacteria all the time because they change their genomes in response to antibiotics and what they do is very simple you remember that difference between one in ten to the four and one in 10 to the 10 that depends as I said on the cell having these repair mechanisms the proofreading mechanisms but you see they can be down regulated that process can be down regulated and what that does is to produce literally millions of new DNA sequences that can then be selected now the selection and I agree there is a kind of natural selection here within the organism now the question is very simple to those new new sequences get to the germline you bet they do and that I'm afraid is where I think the big hole in the theory lies because once you can do that you can get what for example Zhang and his colleagues have shown in a paper published in 2018 I can send all these references to anybody who sends me an email so if you're worried about whether I'm telling the truth just send an email and I will send you the reference what they showed was that a small non-coding RNA that's a little bit of Technology but a new a new sequence generated by the organism can pass to the germline cells which become eventually of course the eggs and the sperm and what that will do is then tell the Next Generation to inherit the metabolic characteristics that were conveyed by that I'm I'm sorry to say this because I know this is a dirty word amongst mostly evolutionary biologists but Landmark is back very simple all right right by the way the um the the the the walking mechanism is simply beautiful it is absolutely films absolutely uncanny um at one point Dennis I thought you were confusing um gene expression which of course is obvious I mean yeah no it didn't confuse them we don't um I that's why we I went on to explain how those changes can then be communicated um because that that's an extremely important distinction indeed yeah there's there's no no dispute whatever about certain G is being turned on in some cells and others in other cells that's that's what embryology is all about however what Dennis went on to say is that there's evidence that it actually gets into the germline and um Lamarck is back uh well if Lamarck is back um in if we're an indefinite number of generations I'm impressed um if it's only for a couple of generations I'm not um but let's suppose that it is for a larger number of generations if that's true then I would have to revise what I say to include any change in the germline then now now becomes admitted into the charm circle of replicators and that's fine um I doubt it um but but I I don't want to be dogmatic about saying that the the the DNA in the existing germline is all there ever was if on some other planet and maybe on this planet it's true the germline can be altered then that's fine we Inc the the broad Church of The Selfish Gene can Embrace that um as I say I doubt it yes okay yes but look I think the one thing to to perhaps make clear to the audience is this is happening in everybody in this room because we had the pandemic that arrived with coronavirus now of course we've fortunately developed vaccines against the virus and that's been our great saving uh Grace but what would have happened anyway with a lot of people dying of course would have been that our immune systems would have done exactly what we're describing that is they would have used that mechanism for hypermutating that is mutating extremely quickly to produce millions of new DNA sequences and then that is used to be what then it gives you the immunity the acquired immunity obviously now what Richard is questioning is okay maybe that can occasionally be passed to the journal line we don't know that yet whether an immune response can be passed to the journal line and I would readily say we don't know that yet but what is important is Rich's point about how temporary it is now it's very important indeed and I agree with Richard about the importance of temperiness or permanence because it seems to me that what these mechanisms give is the option for The evolutionary process to as it were try it out if there's an environmental change that makes it very difficult to survive and all organisms are under stress and they alter their genomes and pass some of that even temporarily onto the next Generations what the next Generations can do is to find out whether they do experience that change environment or not if they don't then it's great that it's temporary you don't have to alter the main genome if it is more or less permanent and goes on for many generations then how can it get assimilated in the genome Conrad Waddington showed how to do that way back in the 1950s incidentally his book the strategy of the genes has been rightly republished in 2014 so you you can buy it again it was published in 1957. he did beautiful experiments on fruit flies he induced changes with very tiny gentle Persuasions as it were from either heat or ether or some other experimental techniques in which he could as he would persuade a few of the fries to show a new characteristic and he actually determined how many generations would you have to continue to do that in order for it to become assimilated into the genome it's about 14. it's not very long now what he was showing is what he called genetic assimilation I think it was a great mistake that Waddington was ignored by The evolutionary biologist not a shame the Waddington effect was actually selection I mean it was not by him well the the flies that didn't respond correctly to the heat shock yeah died yes that's right so it was selected I'm agreeing with you it only looked like numbers maybe the only point in the evening where we totally agree that was selection yes I absolutely agree I'm agreeing with you what Waddington was doing was a simulation of a lamarckian experiment for quite a different reason and I think it comes back to your opening question to to me do you still hold to the idea that it's agency that organisms have rather than a DNA now I do because you see I think what organisms are doing is partly through their social choices effectively choosing which genes they will allow to survive that's what what social social selection yes oh I mean well who you mate with for example we're back to Darwin's idea of sexual selection well we are as a social selection so ideas why why drag the mark in then I think that's the markian because it's part of the use within the social context you see what what landmark was insisting on um was the idea that use and disuse was itself something that could be inherited and I think this is something of course it starts culturally but it becomes something that can be inherited through the fact that you are as organisms choosing the characteristics that you want to survive in the later generations why do we marry anybody isn't that why we do it I mean this this is perfectly darwinian what you're talking about yes absolutely I agree and darwinian Darwin was a lamakian I'm not joking no you're not no in 1868 he published his theory of genuis which is precisely the thing we've now discovered as their exocellular vesicles today so I absolutely totally agree with you Richard Darwin was indeed a landmark and I'm a good darwinian yeah you're a sixth edition Darwin yeah um Darwin in the sixth edition of the original species did uh flirt with lamarchism that is true um that's a historical fact but it's not a very important biological fact oh I think it's extremely important okay well um no seriously Richard because he he he collaborated with this is not very well known he collaborated with physiologists in the last 20 years of his life between 1872 and 1882 he collaborated with my predecessor as the chair of physiology um Burton Sanderson and he collaborated with his student George romanes in a very simple set of experiments because you see took lamarchianism so seriously that he invented this theory of generals and I better just very briefly explain what that is he realized as Richard as beautifully explained that you've got to explain how it can be that the body can in its changes due to use and disuse communicate any of that to the germline otherwise all of that information is Richard beautifully expressed it earlier on would be lost so how can that be communicated he couldn't see what could possibly do that so he invented an idea and he admitted it was an idea which was that tiny particles put out by the cells themselves which he called genules would be able perhaps to pass through the bloodstream down to the germline that was his way of explaining there could be Soma to germline expression but he readily admitted at the time this is just a hypothesis because he couldn't see them now with 19th century microscopy indeed you could not the 20th century microscopy and 21st century microscopy even better we've been able to do so and it's the experiments are simply beautiful just go online and ask to look at extracellular vesicles made evident by labeling molecules fluorescently so they literally glow green yellow red or whatever it might be enables you know this is this particular RNA this is this particular DNA and so on and that escapes the limits of light microscopy you can actually resolve down to a very tiny particles indeed they're called extracellular vesicles those have been shown experimentally to be passed to the germline that's how the rnas and dnas the new rnas and dnas get to the germline so I think that if he was alive today I think Charles Darwin would be praising and cheering the discovery of extra cellular vesicles they are his generals and they carry out the function that Darwin proposed now why did you spend the last 20 years of his life collaborating with George romanis is because he actually thought this must be right so I don't think it's trivial that Darwin was a lamakian okay I think I do think this is actually quite misleading um what Darwin's generals was supposed to be about was investigating the the current state of the body and passing it on to the next Generation so the generals were going all around the body and they were um detecting changes in the body um the sort of classic Lamarque and examples like the blacksmith's arms getting muscular and the giraffe's next stretching and things like that um Lamarck thought that those were inherited Darwin in his later years thought they were too uh and um the general Darwin's generals were going around the body in the bloodstream and picking up information about the current state of the body the modifies date of the body the acquired state of the body and going to the germline going to the gonads and imprinting the information into the germline now that is a very radical idea that's precisely what the exocellular physicals are doing well yes but but they're not it's nothing to do with blacksmith's arms it's it's it's it's the they may be doing something if you're right about the immune system you know you seem to be suggesting that what happens is that when when the immune immune system uh reacts to an infection like covid and um and we become immune to it that immunity gets passed on now I know I deliberately said we're not yet sure about that I know you did and I'm glad you said what we are sure about is that other things are passed on metabolic disorders are passed on and sexual preference are passed off the rational preferences in what in what way passed on it's passed on in planarians and that's been demonstrated again all of these references I'm very happy for people to email me and ask for them um but that's been shown very recently by toker and his collaborators in work in Israel and I think that is actually a 2021 and how many generations well what they're showing okay come back to the point I made about temporary and permanent because you see temporary is actually an advantage if you don't yet know from an evolutionary perspective whether the change is valuable or not I think it's great you see that epigenetic changes and and temporary alterations of the germline are not necessarily passed on through many many thousands of generations because if the change in the environment is is really temporary you don't want a permanent response so I can see the evolutionary logic of doing it in that kind of way you keep it soft until it needs to become hard and then you let it become hard you let it then become assimilated into the genome well that's fine I mean that that's coming back to the Warrington effect in a way to some extent yeah yes I think this is why I said that Waddington was um badly ignored or or sometimes called the Baldwin effect sometimes called um yes but I think what what's happened today is that we actually now know the precise mechanisms by which it can happen we know the molecular biology we know the cellular biology of it so what I'm saying is it's time for evolutionary biology to catch up I mean yeah if I may ask in that case how long would it need to be I mean you've asked a few times I'm really taken by this sort of temporal thing how long would it need to be to have an effect do you think in order to be evolutionarily interesting then it it needs to be something that we we see as a change in the gene pool um and uh changing the gene pool would be would be I mean I can't put an actual number of Generations on it but but it's it's it's it's it's not a proper darwinian change if it's just um uh for example the the there's there's evidence that starvation effects yes and these are um uh as it were I mean epigenetic effects on our changes in the as the embryo develops changes in the expression of genes in different parts of the body so in liver cells certain genes are turned on in kidney cells are the genes Eternal muscle cells and other genes are Terminals and those are epigenetic effects now there is some evidence that those epigenetic changes can be inherited into the Next Generation and possibly the grandchild generation that's not a a proper gene pool change yeah I think Richard is right on that but what we would need to do is to look at the effects after billions of years and that's exactly what the Human Genome Project did in its nature paper of 2001. remember I've heard to figure 42 of that paper you see there the evidence that those genomes were changed by moving great chunks around in the genome not time I guess to go through the detail of that but unfortunately that's fairly clear evidence that it must have happened during evolutionary time scale fascinating it's obviously also important to say that increasingly with modern Technologies people are starting to look at sort of the genomes of um other humanoid species and looking into the past to sort of get more information on on perhaps what our more recent ancestors look like and it might be quite interesting to sort of see whether or not that those pieces of data can can add to to this conversation in in due course what bothers me is is Dennis is saying Lamarck is bad because because in order for Lamarck to be back it seems to me we would need to have something more like the blacksmith's arms effect where where an adaptation and I mean there's plenty of adaptations that happen in lifetime you your muscles develop when you when you use them it will be wonderful maybe on some other planet it happens that when your muscles develop when you're you get a suntan when you when you all sorts of adaptive changes like this get inherited and that's what Lamar was suggesting and I think to say that Lamarck is back is is going to give a misleading impression because people will think you're saying that something like the giraffe effect the blacksmith be very precise it is that the inheritance of use and disuse is now evident that's the way I would well well yes is it I mean you're not going to go out and say that that that adaptation as we see it in the field as as animals develop camouflage as animals develop stronger bones as they as they use them stronger muscles as they use them that would be a proper lamakian effect that would be a real adaptive change as a consequence and reduce and disuse when we know that the rnas that communicate all of that can be transmitted to the germline oh my gosh so we've got part of the evidence that of obviously I mean what I would want to say on this is this is open field for experimentation in the future that's what we need we need to be open to those possibilities on that delightful note please can we take a moment to appreciate the Civility and eloquence with which these two gentlemen have debated and disagreed this moment can you sign my book Dennis oh my gosh look at this oh this is fantastic look at this foreign [Applause]

Channel: TiMMoTEuS

Views: 59,994

Keywords:

Id: uLC0akD1WOE

Length: 48min 48sec (2928 seconds)

Published: Fri Jun 09 2023