Revolutionary: Michael Behe and the Mystery of Molecular Machines

for thousands of years humans have invented ways to propel themselves through water but long before humans invented their propulsion systems nature developed its own methods of moving through liquid space not only in fission of the large aquatic creatures but in organisms so tiny they cannot be seen by the naked eye perhaps the most amazing propulsion system on our entire planet is one that exists in bacteria it's called the flagellum a miniature propeller driven by a motor with many distinct mechanical parts each made of proteins the flagellum motor resembles a human designed rotary engine it has a universal joint bushings the stator and the rotor it has a driveshaft and even its own clutch and braking system in some bacteria the flagellar motor has been clocked at a hundred thousand revolutions per minute the motor is bi-directional and can shift from forward to reverse almost instantaneously some scientists suggest it operates a near 100% energy efficiency all of this is done on a microscopic scale that is hard to imagine the diameter of the flagellum motor is no more than five millionths of a centimeter the bacterial flagellum is one of many molecular machines that scientists have discovered in the last several decades including energy producing turbines information copying machines and even robotic walking motors the origin of these exquisite examples of nanotechnology is a mystery that has generated heated controversy among biologists over the past two decades and it's a mystery that has transformed one man into a scientific rebel willing to challenge one of the most cherished ideas of the scientific establishment [Music] [Music] [Music] biologist Michael Behe is an unlikely figure for a revolutionary I never was interested in stirring up the hot just for fun I'm basically shy I you know don't like to give anybody unnecessary trouble a mild-mannered professor at Lehigh University B he received his PhD in biochemistry from the University of Pennsylvania one of America's top research universities he spent his early career as a member of the scientific establishment publishing peer-reviewed articles and science journals and receiving research funding from the National Science Foundation and the National Institutes of Health but by the early 1990s B II was toying with heresy another aspect of my personality is that I'm stubborn if I see something and I mention it and nobody has a good reason that they can answer me without I'll stick with it and and especially in this area I'm a scientist I'm supposed to want to know how biochemical systems came to be be he found himself with growing doubts about one of the central tenants of modern biology Darwinian evolution according to the modern version of Darwin's theory known as neo-darwinism even the most complicated biological features originated through a process of natural selection sifting through random mutations or copying errors in the genetic instructions stored in DNA for example a random genetic mutation might give a particular bird of slightly longer beat this small change could help the bird survive better and eventually its offspring with longer beats would come to dominate the population a longer beak size might not seem all that important but Darwinian theory asserts that over time many similar unintended changes could accumulate ultimately producing an organism radically different from its original ancestor according to Neil Darwinism new species and new biological features do not develop according to an intelligent plan instead they arose from the accumulation of thousands of small undirected genetic mistakes over millions of years the more Michael Behe study the staggering complexity of life at the biochemical level the harder he found it to believe the standard power when Ian's story the bacterial flagellum was one of the biochemical systems that fueled Behe skepticism the bacterial flagellum is literally an outboard motor that bacteria used to swim it's uses a little piece that spins round and around and round and pushes against the water just like a propeller does in an ordinary outboard motor on a boat in our everyday world and the propeller is attached to a driveshaft which is attached to a motor which has clamps holding it in place and and dozens of pieces that are required for it to do its job it's just a fantastic example of what science has discovered and that is molecular machines the first time be he saw a diagram of the flagellum he was captivated I look at and says wow that's really fascinating I wonder how that evolved then had turned the page and say go on do something else and just my any skepticism was defeated by assuming that somebody must know this because everybody says Darwin's theory is true but then B he read a book by geneticist Michael Denton Denton argued that Darwinian theory was in crisis because its mechanism of random mutation and natural selection wasn't capable of producing major biological innovations after reading Denton B his doubts about the origin of molecular machines like the flagellum grew then I went back and said well who does know how this could have evolved and nobody had anything to say about it even hand-waving speculations were hard to find B he began to dig deeper to find an answer Darwin's theory says you have to start with something that's working a little bit and then it will change mutate a bit and that helps a little bit and that'll be selected and then it improve a little bit more and a little bit more until you get the full fledged system I said well it does not look like some of these systems can be done that way because they need all of these parts you know if you don't have this one it's not going to work you can't take any of the parts away it's kind of sitting in my desk scratching my head you can't take the parts away you can't can't reduce it at all it's irreducible and it's so it's irreducibly complex I thought bingo that that encapsulates the the problem for Darwin's theory right there B he decided to write a book explaining his heretical ideas published during the summer of 1996 Darwin's black box quickly attracted attention Darwin supporters had insisted that there were no credible scientific objections to Darwin's theory but now a scientists at a mainstream American University was saying otherwise my editor called from Free Press and he says okay the the books going to be out in the beginning of August and the New York Times is going to do a review you know the week before it was reviewed everywhere the New York Times National Review Nature technical science journals popular publications the the term itself irreducible complexity entered the lexicon where it's still very alive it's become part of the scientific descriptive toolkit if you will at that point I realized that you know this was I had gotten into something I had not anticipated it got a lot more discussion than and I had ever dreamed about the bacterial flagellum was one of the central examples of irreducible complexity be he highlighted in his book if you take away the propeller if you take away the motor if you take away the clamps that hold it onto the cell's membrane take away any of a number of different parts it's not that the flagellum is going to spin half as fast as it used to or quarter it's broken and it doesn't work at all it's like taking the propeller off of an outboard motor on your boat and wondering how far now you can you can go in the water you can't go anywhere so that's a problem for Darwin's theory because Darwin's theory says that things evolve by working a little bit you know maybe not very well but a little bit and then a mutation a change comes along that helps it move a little work a little bit better and that helps the organism survive and have more offspring and so then another change comes along and another another and it gradually builds up to the final structure well that might work for some things but it doesn't work for systems that are irreducibly complex things like the bacterial flagellum because well if you wanted to build an outboard motor for a boat what would you start with when you start with say just an iron rod that you know in the future would attach a motor to the propeller well what's that going to do it's not going to do anything would you start with just a propeller well that's not going to do anything it's not attached to anything would you start with just a motor well that's not going to propel you anywhere so with irreducibly complex systems like the flagellum darwin's idea is dead in the water like a boat with an outboard motor that doesn't work natural selection selects or favors in variations that confer a functional advantage on a system many of the simpler versions that you could imagine of the bacterial flagella motor perform no function at all and so if you imagine trying to build a flagellar motor adding parts one by one until you finally get to the complete system you're going to encounter configurations of parts that confer no function in which the motor simply will not work at which point the evolutionary process will terminate it will cease to continue because the system conferring no function will not be preserved and passed on to the next generation d he didn't just challenge the Darwinian explanation for the flagellum in his book he also offered a controversial alternative explanation proposing that the flagellum was produced by intelligent design the fillet Gela motor and other molecular machines certainly look as if they had been designed by an intelligent engineer but Darwin and his modern followers claim that the unguided mechanism of natural selection and random variation could mimic the powers of a designing intelligence giving rise to the illusion of design in nature yet according to be scientists had now discovered irreducibly complex systems in biology that could not be explained by Darwin's mechanism perhaps be he reasoned the appearance of design was not an illusion after all the question is how do we recognize design how do we realize that something has been put together intended by an intelligent agents probably the only real way that you can do it without taking somebody looks at word for it that they've they have put something together is by recognizing what's called a purposeful arrangement of parts think of say Mount Rushmore you look at the rocks to the left of the images of the presidents and you know they don't look like much of anything and you look at the images the rocks that are in the shape of the images and you immediately realize that it was designed you know even somebody who had never heard of Mount Rushmore before from another country or would immediately realize that it was designed and the question is why well because the shape of the rocks are matched to each other they're ordered there together for a purpose and the purpose is to portray the image of the residents we humans are good at recognizing design if you go down the street and you see some neighbor's yard that has dandelions around it is a guy you should really take better care of his yard then you look to the right you see a patch of tulips you know nicely cultivated next to the mailbox or something you immediately know that the tulips were intentionally quit they're not to get all philosophical here but if you ask yourself how do you know you're not the only intelligent being in the universe it's because you see other people doing intelligent things like arranging words so that they make sense and into books and so on or arranging paint into paintings or arranging pieces into machines or doing intentional activities it's a very deep part of our own minds our own intelligence that we can recognize the effects of the intelligence of other beings in the purposeful arrangement of parts whenever we see tightly functionally integrated systems we know of only one cause that has produced those features and that causes intelligence that's what we know from experience and and so when we see a feature like that in living systems given there's only one known cause of what B he calls irreducible complexity or functional integration of parts and that causes intelligence I think we can reasonably infer that that same kind of cause was at work in the origin of that system in biological systems and therefore intelligent design isn't just an argument from ignorance it's an argument based on what we know about the cause and effect structure of the world that only intelligence generates irreducible complexity or or tight functional integration of parts and that's what we see in living systems therefore living systems were produced by designing intelligence even more than bees critique of Darwinian theory his proposal that biological marvels like the flagellum pointed to intelligent design provoked a backlash critics accused Behe of pushing religion not science although he is a committed Roman Catholic bee he explained he had never had any theological objection to evolution and he pointed out that his inference to design was based on empirical observations and scientific reasoning not faith me he also made clear that although he believed in God he didn't think the evidence of design and biology was enough to identify the designer on its own all it could do was establish whether something was the product of intelligence over the next several years supporters of Darwin's theory aggressively tried to refute bees arguments and any quote argument or evidence against evolution that overlooks the fact that parts of this system have functions on their own is certainly not going to cut it their efforts ultimately culminated not in the lab but in a courtroom in a high-profile legal battle be he would soon find himself and his ideas on trial today the small town of Dover and southeastern Pennsylvania looks peaceful but in 2004 it became the battleground for a bitter conflict that attracted attention from around the world - conflict arose after the Dover Area School District required the reading of a short statement about evolution and high school biology classes the statement told students that Darwin's theory had gaps and continues to be tested as new evidence is discovered if further announced that there was a view that differed from Darwin's theory called intelligent design and if students wanted to learn more about it they could read a book that had been placed in the school library the statement concluded by encouraging students to keep an open mind when it came to any scientific theory on its face the Dover statement did not seem to be the stuff that epic battles are made of supporters of Darwin's theory however were furious they insisted that reading the statement was equivalent to the state endorsing religion ironically many supporters of intelligent design also opposed the Dover policy including Discovery Institute the non-profit think tank with many Pro intelligent design scientists were affiliated Discovery Institute actually opposed what the Dover School District wanted to do about intelligent design and we asked them to repeal their policy because we didn't want intelligent design become a political football the ACLU eventually filed suit alleging that the Dover policy was unconstitutional this board acted with a clear and unconstitutional purpose the case was assigned to federal district court judge John Jones a former trial lawyer and head of the state's Liquor Control Board Jones had a long career in Party politics most judges tried to stay out of the limelight but Judge Jones made himself readily available for media interviews he even speculated about a future film version of the trial telling reporters he hoped Hollywood star Tom Hanks would play him on the screen at the same time Judge Jones expressed interest in an earlier movie [Music] judge Jones told one reporter he planned to watch the 1960 film inherit the wind to supply him with historical context for the case in her at the win was a highly fictionalized account of the Scopes Monkey Trial of the 1920s where high school teacher John Scopes was prosecuted for violating a Tennessee law banning the teaching of human evolution historians have argued that inherit the wind reduced history to blatant stereotypes portraying the debate over Darwin's theory as a stick-figure battle between bigoted fundamentalists and open-minded scientists it was a strange film to watch for someone who is supposed to be impartial the key legal issue presented in the Dover case was the limited question of whether the school board acted with a non-religious purpose but lawyers on both sides wanted to expand the focus to place intelligent design itself on trial intelligent design is not science intelligent design is just creationism in its new name living a little more than a hundred miles away from Dover Michael Behe had mixed feelings about the case he was interested in science not politics but the ACLU was trying to place his scientific argument for intelligent design on trial so B he agreed reluctantly to serve as an expert witness in order to defend his ideas but bacterial flagellum soon became the trials poster child as ACLU attorneys tried to undermine bees credibility their first expert witness was Brown University biologist Kenneth Miller I don't think it's a valid scientific theory I don't think it's good education and I don't think it has any places in the classrooms in Dover Miller challenged B his claims about the flagellum head on he explained that molecular machines like the flagellum could have been built by natural selection from pre-existing components that originally had different functions Miller then announced to the court that he had developed a test that would conclusively prove whether the full of jela was irreducibly complex dr. B his prediction is that the parts of any irreducibly complex system should have no useful function therefore we ought to be able to take the bacterial flagellum break its parts down and discover that none of the parts are good for anything except when they're all assembled in a flagellum if dr. B he is correct if we take away even one part there should be no function the flagellum is built out of proteins and for his tests Miller said he would propose taking away not just one or two proteins from the flagellum but 30 if be he were right surely taking away so many parts of the flagellum should leave a completely non-functional Miller then dropped his bombshell when the 30 proteins are removed the remaining 10 proteins are not with a function instead they reveal something called the type 3 secretion system and some other bacteria this secretion system forms a simple and needle complex a moleculus of Rindge used to inject toxins into a host organism for Miller the type 3 secretion system needle complex supplied a definitive refutation of B G's claims about the flagellum it showed that evolution could have built the flagellum by co-opting a pre-existing simpler system what that means in ordinary scientific terms is that the argument that dr. B he made is falsified it's wrong it's time to go back to the drawing board nine days later B he himself took the stand and offered a detailed refutation of Miller's claims D he argue that Miller had misrepresented his eye of irreducible complexity be he did not claim that when one part of an irreducibly complex system is removed the remaining parts could have no function instead he argued that when one part is removed the system as a whole no longer functions in the case of the flagellum if you take away one of its key parts the system doesn't operate at all as a propulsion system as for Miller's proposal that the flagellar motor could have evolved from pre-existing parts with other functions B he responded that this scenario while logically possible was highly improbable it relied on the assumption that natural selection could co-opt existing parts and redeploy them to create the flagellum motor there are some examples where I think such a thing can happen but that's not going to help in irreducibly complex systems like again the flagellum suppose you said I want to build a mousetrap and I'll go into the garage and try to co-opt some old things that I find there for use in the new mousetrap and you see that a mousetrap needs a spring and in your garage you have an old clock so you pull out a spring from that and you see that the mousetrap has a metal bar and you've got a crowbar in your garage and you see that it's got another metal piece the hammer and you've got you know the fender of a bicycle well you can't make a mousetrap from all those pieces because they have been fit for their other roles and they will not work as pieces of mousetrap unless they are extensively reworked or refitted and that of course is intelligent design even under a Darwinian view you would not expect pieces to be laying around that would be fit for roles in other complex systems because you would expect natural selection to shape them very tightly to the role that they are currently fulfilling and so to be used for something else they would have to be reshaped retooled before being used and then you have the problem with irreducible complexity all all over again [Music] but what about Millers bombshell that type 3 secretion needle complex didn't that prove that the flagellum had evolved from a simpler structure through undirected natural selection B he had a surprise of his own he pointed out that a number of evolutionary biologists actually thought the needle complex had evolved after the flagellum and if the needle complex arose after the flagellum there is no way it could have been used by the evolutionary process to build the village Elam in fact it was possible that the needle complex actually devolved from the flagellum but if that's the case you know that doesn't help Darwinian evolution at all because you know having a fantastic machine which degrades to give a simpler machine as is not an impressive example of the power of Darwinian evolution that might be compatible with intelligent design is certainly incompatible with Darwin's theory or at least it doesn't help it at all but there was an even more fundamental problem with Miller's hypothesis according to B he even if the needle complex had existed before the flagellum that fact alone did nothing to show how it could have been transformed into the flagellum by natural selection acting on random genetic changes it's not enough for advocates of co-option to identify a single possible intermediate structure instead they must show that a series of intermediate structures existed that could have maintained some function at each stage in the evolutionary process but in the case of the bacterial flagellum experimental evidence cast down on that idea we know from genetic knockout experiments that the 29 part the 28 part the 27 part the 26 part version of that machine simply will not function it will not work as a as a rotary engine and so building up through those stages of non function is not going to happen because there's nothing there that will confer a functional advantage on an organism that will then passed on to the next generation and therefore the evolutionary process will terminate when it encounters one of those non-functional thresholds in this alleged sequence from something simpler to the flagellar motor in the final days of their trial Bea's testimony was backed up by another biologist named Scott Minich a microbiology professor at the University of Idaho many conducted lab research on the flagellum the year before Minik had come out in the scientific community as a supporter of intelligent design he co-authored a paper for scientific conference with philosopher of science Stephen Meyer in the paper many can Meyer argue that the flagellum was best explained by intelligent design as many told the court his decision to submit the paper had been a difficult one at the time he was in Iraq as a member of the Iraq survey group searching for biological and chemical weapons for the US government things had begun to deteriorate in terms of the military situation at that time we had a deadline to get this paper submitted it was looking at the flagellum is an argument for irreducible complexity and intelligent design Steven made his final edits I had made mine I was in the top of the perfume palace in one of the Saddam's complexes near the airport this large dome structure up on the top floor and the deadline was midnight in London to get this paper in to participate and I was hesitating you know do I really want to do this whether the consequence is I'm gonna lose my job I'm gonna be able to support my family I was alone up there with one other young military I think it was a corporal and just in a mortar round went off estimated that it was about 300 meters away it catches your attention I mean it's a pretty loud explosion but then another one came in a few seconds later and this one was much closer probably about 200 meters we were estimating and then another one came in whoever it was we're walking these rounds right towards you know the perfume palace and so then I said well you know I may not be here tomorrow boom I hit the send button and it was done MINIX decision to testify at Dover proved to be personally costly there were people in my university I don't know who they were but they went to the president complained they went to the University of Washington where I had affiliate status because I teach medical students through the University of Washington system in Idaho trying to get me fired saying I was incompetent if I believe in this stuff nobody asked me ever what I believe I never taught this in the classroom but I ended up getting censured on the witness stand minute reiterated the evidence that the type 3 secretion needle complex had developed after the flagellum he also challenged co-option scenarios as highly speculative and biologically implausible but in the end it didn't matter a few days before Christmas Judge Jones issued his ruling he didn't just strike down the dover school policy as unconstitutional in a blistering 6,000 plus word for teeth he also concluded that intelligent design was not science thank you judge Kang this is an absolutely thrilling decision many scientists and the news media lavished praise on the judge Time magazine featured him on its cover as one of the world's most influential people in the category of scientists and thinkers PBS later staged an elaborate reenactment of the trial for its documentary titled Judgment Day intelligent design on trial the documentary showcased the type 3 secretion needle complex which was depicted as devastating evidence against bees argument for intelligent design VIII he and MINIX detailed responses at the trial were conveniently left out for many people certainly those in the media the case for intelligent design of the flagellum I'll appear dead killed by an impartial federal judge it didn't take long for that assessment to begin to unravel science is not decided by judges a number of legal scholars who don't like intelligent design criticized judge Jones for actually going way beyond the legal questions the part of Kitzmiller that finds intelligent design not to be science is unnecessary unconvincing not particularly suited to the judicial role and even perhaps dangerous to both science and to freedom of religion professor J Wexler Boston University School of Law more questions were raised when critics did a detailed analysis of Judge Jones critique of intelligent design and made an astonishing discovery more than 90% of Judge Jones analysis of intelligent design was basically cut and pasted from legal documents given to him by lawyers working with the ACLU right down to the factual errors in their briefs so when they would misquote someone like biochemist Michael Behe he would misquote Michael Behe with the same misquote because he didn't even bother to go back to the record to Rivera Phi the quotes he just cut and pasted but perhaps the most revealing development involved the bacterial flagellum during the trial attorneys challenging the school district confidently assured judge Jones that the flagellum was easy to explain in Darwinian terms however just a year later one of the scientists who had advised the ACLU in the case co-authored an article in a science journal that made a startling admission attempting again to refute these ideas the article conceded that the flagella research community has scarcely begun to consider how these systems have evolved in the years after Dover it became clear that the answers offered by Darwin's supporters during the trial were not enough to silence questions being raised by scientists like me he the controversy over new scientific challenges to Darwin was continuing to spread not only in America but around the world and Michael Behe and the bacterial flagellum was still playing starring roles as a major scientific exhibition in Europe was about to show [Music] 2009 marked the bicentennial of Darwin's birth and the 150th anniversary of his landmark book on the origin of species around the globe supporters of Darwin planned a year-long celebration in Germany one of the largest Darwin anniversary events took place in the city of Stuttgart at its State Museum of Natural History the exhibition was directed by german paleontologist goethe Beckley one of the museum's curators we had about 100,000 visitors on the complete exhibition together with a program that was accompanying this exhibition was one of the largest if not the largest event in the course of the domineer celebrations in germany Beckley decided to use the exhibition not just to celebrate darwin's theory but to make clear to the public that there was no debate about Darwin's ideas among scientists in order to refute the growing idea of intelligent design Begley decided to include a display on the bacterial flagellum the reason why we selected the flagellum as he hosts the chives to basically expose intelligent design was that the bacterial flagellum has a kind of iconic status we build a mobile model of the bacterial flagellum and have this animation to show that it could originate naturalistically the exhibit highlighted the type three secretion needle complex as an explanation for how the flagellum could have evolved in addition to an exhibit about the flagellum begley came up with a display to dramatize for visitors the overwhelming scientific evidence for Darwin's theory it was a balanced with books art and the plan was on one side of the balance we would have all the books against evolution books by creationists intelligent design proponents and on the other side of the balance we would have one book the original species but the balance goes down on the side of the one book because this is the real heavy evidence but the display didn't have quite the result intended and I made one big mistake I read the books on the lightweight aside the apparent lightweight Sun and what I recognized to my surprise is that the arguments are found in those books were totally different from what I heard either from colleagues or when you watch youtube videos where the discussion is around intelligent design versus neared of Indian evolution and I had the impression on one side that those people are mistreated their position is misrepresented and on the other hand that these arguments are not really receiving an appropriate response and they they have merit one of the books Beckley read was Darwin's black box read novels by a black box would be basically introduces this concept of irreducible complexity Beckley soon realized that proposed Darwinian explanations for the origin of the flagellum didn't work the type 3 secretion needle complex was no help because it probably developed after the flagellum this is a reduced flagellum motor and not a precursor of a flagellum motor in addition the suggestion that natural selection could have gradually built a flagellum by co-opting parts from other systems didn't make sense it is graphically convincing but if you know the ontogenesis of the the flagellar motor then it is completely ridiculous it cannot where you cannot build the flagellum by just adding outside of the cell wall some some protein elements on it and make the the flagellum longer and longer this kind of scenario doesn't make sense in terms of the ontogenesis of the structure like be here a couple of decades earlier Beckley began to dig deeper and so when I read those books on intelligent design and on the books part might be he and Bill dam ski and the the purposes Steve Meyer we're not existing them so I thought there is some merit to it and I made contact with some of the representatives of the intelligent movement the next thing I found out it that there are much different from what I expected they're open-minded there they're not religious fanatics who try to push a kind of theocratic system onto society under the label of intelligent design they are really interested is this neo-darwinian story really true or is there scientific reason to doubt in Beckley didn't fit the usual stereotypes of a Darwin skeptic so many people will think as somebody who comes to doubt the neo-darwinian process and and embraces intelligent design probably was religious from the very beginning probably as an evangelical Christian and has his ax to grind his his religious ax to grind I came via totally different path to the views on I don't know I'm coming from a family background which is totally secular agnostic was not baptized didn't join any kind of religious education never went to church so I was completely irreligious was not even interested for most of my life in in philosophical or metaphysical equestranaut was interested in nature in animals and and Natural Sciences Beckley publicly disclosed his support for intelligent design for the first time in 2015 as Bentley was thinking through his doubts about Darwin in Germany and American scientists was conducting lab experiments that would expose just how daunting the challenges facing Darwinian explanations rarely are Douglas axe earned his PhD at Caltech he then spent 14 years doing research in molecular biology at Todd labs in and around Cambridge University ax was skeptical of Darwinian evolution and he wanted to find ways to actually test what it could and couldn't do when ax returned to America he formed biologic Institute to do just the axé doesn't work on the bacterial flagellum but he and his colleagues and Gager and Massey Reeves have conducted experiments that help address the feasibility of Darwinian explanations of the flagella those explanations depend on the idea that natural selection can easily reuse existing parts and adapt them for new functions but axes experiments raise two problems for this and other Bell whinnying claims I refer to these is the big problem in the little problem one is the big problem of inventing an entirely new protein structure to do something new and the smaller problem is tweaking in an existing structure so that it does something slightly different clearly one of these is more challenging than the other and my work early on showed that the bigger problem was was beyond the reach of evolution you have to get too much right in order to get a new structure to form in order for accidental causes to get these new structures so my colleagues and I am gauger in particular started to look at the smaller problem which is can you take an existing folded structure and evolve a new function for it and somewhat surprisingly we found that even this smaller problem is too hard for Darwinian evolution at least in the cases that we've examined the number of changes you have to make to an existing structure to get a new function to be performed by it is beyond what you can get by random mutation by Darwinian evolution critics abhi he has suggested that natural selection could build complex new machines such as the flagellum by co-opting simpler molecular machines made up of several protein parts but as his research seemed to show that co-opting even one existing protein to perform a slightly new function was beyond the reach of the Darwinian mechanism after dover b he published a new book that helped explain why he showed that building many complex biological structures and even new proteins would likely require multiple coordinated mutations many many different biological processes will require multiple mutations before they're going to have an effect but according to B he new studies and population genetics show that coordinated mutations were beyond the reach of natural selection in many cases long in the short is that if you need more than one thing to happen at a time the in probability of getting the correct two mutations goes up exponentially if you need to change one particular subunit of DNA well there's three billion subunits in a mammalian cell so the odds if you need one particular one that's well one in three billion okay well that sounds like a lot but there might be billions of organisms around yeah or at least over time but if you need to that means you need one or three billion times one in three billion it goes up exponentially you have to multiply them together and so you very quickly run out of of probability these analysis helped explain why a growing number of lab experiments have demonstrated the limits of the mutation natural selection mechanism since the late 1980s Michigan State University biologists Richard Lenski has been running a long term evolution experiment with E coli bacteria a staunch supporter of Darwinian evolution Lenski wanted to follow a population of bacteria over time and see what new functions would evolve I'm a big fan of this experiment because it it does not put out a model it's not a computer model it's not a theory what he did was let evolution happen on its own and say what did it do 20:14 Linsky and his researches had grown over 60,000 generations of bacteria that's equivalent to say a million years in the lifespan of a large animal like us and there have been trillions upon trillions of different bacteria that have been born and died in his flasks although often cited as providing evidence for Darwin's theory olinsky's experiments are perhaps most revealing than what they haven't produced we don't find a new protein with a new fold with a new function by and large these are deletions insertions rearrangements of information that's that's already present he didn't see anything like the evolution of some new complex system like the flagellum nothing remotely like that at some point you're gonna have to show that you have a gene with one function has now evolved into a gene with a different function different protein folds and we're still waiting what we see going on in the vilensky laboratory and other places too is that Darwinian processes or random processes degrade information they do not build it they are not putting in new information they might tweak something here there and at the margins you can have differences about what you call information taken together this flood of new data has raised a powerful challenge to claims that natural selection can explain the origin of new functional genes and proteins let alone a complex biological machine like the flagellum at the same time new hurdles to the DOE inian mechanism are also being raised that are specific to evolutionary accounts of the flagellum itself for example evidence has continued to accumulate that the type 3 secretion needle complexed was not a precursor to the flagellum after all the flagellum definitely came first mutation density studies show that genes and bacterial flagella have experienced more mutations than genes and type 3 secretion complex's genes that have experienced more mutations are generally presumed to be older we find flagella across all phyla of the bacteria very deep the mutational densities are great for bacterial flagella we find them arranged in the same genetic Arrangements on the chromosome across general across families for the most part there's been some rearrangement it was part of the aboriginal chromosome of these organisms in contrast type 3 secretory systems we find in a very narrow range of gram-negative bacteria they've been imported and the mutational densities are much shallower which means there are newer structures compared to the the flagella the supposed killer explanation against B he has turned out to be a dud the needle complex can't explain the evolution of the flagellum because it didn't even exist until after the flagellum but there's more Darwinian explanations of the flagellum assumed that parts already existed that natural selection could reuse in order to build a flagellum this may well explain some features of the flagellum but there's a big problem key for Gela parts are turning out to be unique they don't appear to exist anywhere else they are only found in the flagellum and if they didn't exist already natural selection wouldn't be able to use them to build something else even if all the necessary parts were there for natural selection to co-opt its now becoming evident that just having the parts of known wouldn't be sufficient complex structures almost always require a specific sequence of assembly when building a house a foundation must be laid before the frame can be put up and the frame must be completed before the roof can be added in a similar way a flagellum must be built in a carefully orchestrated process that is governed by assembly instructions encoded in the DNA merely having the various parts of the flagellum available in the vicinity of a bacterium isn't enough even if you had just floating around a type 3 secretory system or a hook protein or a rotor or a drive shaft you've got to put these things together and biological systems aren't put together like Lego bricks you don't just stick them together there's a very precise sequence of expression of these genes these protein part products that allows the machine to be built piece by piece somewhat like the assembly apparatus in a in an automobile factory that assembly routine involving multiple different genes and regulatory proteins is itself arguably an irreducibly complex system you remove any one of those genes or one of those regulatory proteins the flagellum is simply not going to get built it's something will shut down the biosynthetic pathway if if one of those key elements is missing so co-option and in an attempt to get around the irreducible complexity of the finished product posits a bunch of parts which could only be plausibly put together by another irreducibly complex system so you haven't really solved the problem the existence of assembly instructions required to build a flagellum isn't simply a challenge to Darwinian evolution it also provides evidence of intelligent design encoding the assembly instructions requires massive amounts of biological information but where does that biological information come from the genome is full of information it has literally a sequence of DNA letters which tell the machinery of the cell what to make it's like a blueprints we know of a cause that can produce digital code hierarchically organized information integrated circuitry and that cause is intelligence in fact that's the only known cause that we know of based on our uniform and repeated experience the basis of all scientific reasoning about the past that we do out know of that can produce information and therefore it is possible to infer from those effects information information processing circuitry back to intelligence as the best causal explanation of those complex molecular machines more than two decades after the publication of Darwin's black box the challenges to Darwinian explanations of molecular machines like the flagellum have become even more daunting as a result evolutionary biologists are scrambling to find new unguided mechanisms in order to avoid facing the alternative proposed by Behe and others that biological systems reflect intelligent design Michael Behe raised ideas that even now are reshaping how we understand biological systems the man who describes himself as I helped spark a revolution well one things I like about Mike B he is that he's very he's a very humble and unassuming guy he's not full of himself yet he's a player on the world stage scientifically people all over the world know of his idea of irreducible complexity they know of the idea of intelligent design because of his work and it's really reframed the debate whether you agree or disagree is one way or another you've got to now address the question of the origin of these irreducibly complex systems that we find in living systems whether we're talking about the flagellar motor or the ATP synthase or the kinesin walking motor protein or the circuitry or the gene expression system or whatever it is the biology inside the box is really complex and it's an integrated and functional complexity that requires some kind of an explanation and I think just by highlighting that Mike has reframed the debate in a way that I think has changed the way people think about biology in the 21st century for Behe the most satisfying part of his intellectual journey isn't getting recognition it's opening minds I remember in particular a time I was talking at the University of Massachusetts at Amherst and also on the stage and also talking it was not really a debate but a kind of a different perspectives on issues was a lady named Lynn Margulis who was a very prominent biologist a member in the National Academy of Sciences and there were about a thousand students in the audience there was reporters from the New York Times the president of the university was there I was it was great and after discussing it I had a number of students come up saying exactly that that they hadn't thought about it from this perspective before they thought either that you had to be for evolution you know quote unquote or for creation quote unquote or that you know you couldn't have scientific reasons for being skeptical of Darwin's theory and they kind of scratch their heads and say yeah I don't have to think about that and that's the moments that a teacher like myself just lives for [Music] get ready for the revolution it's coming to you now it's coming to you now [Music] a generation stop well Game Change [Music] get it brother [Music] come [Music] feel the rush bicha favorite song [Music] raishin please Oh [Music] I'm ready for the [Music] [Applause] [Music] [Music] you [Applause] [Music] [Applause]

Channel: Discovery Science

Views: 210,442

Keywords: science, philosophy, biology, evolution, Darwinism, neo-Darwinism, human origins, science and faith, intelligent design, Discovery Institute, Charles Darwin, biologic institute, icons of evolution, darwin's doubt, Stephen Meyer, Jonathan Wells, Douglas, Axe, Evolution News & Views, Michael Behe, William Dembski, John West, Jay W. Richards, Darwin Day in America, Darwin's Black Box, Privileged Planet, irredicuble complexity, edge of evolution, Evrim, Akıllı Tasarım, Doğal seleksiyon

Id: 7ToSEAj2V0s

Length: 59min 55sec (3595 seconds)

Published: Mon Sep 11 2017

Reddit Comments

[u/MRH2]

From scanning it quickly, it seems to spend a lot of time on the bacterial flagellum. Unfortunately it doesn't discuss one of the most amazing features of it: how the flagellum is built from inside the cell! https://www.youtube.com/watch?v=v1NnMmw8v80 There's another video somewhere about how the correct length of the hook and the flagellum are determined (so it knows when to stop building it). Amazing.

There seems to be some stuff about the problems with protein evolution, but no other Molecular Machines - which is disappointing. I'll end up watching it anyway.

[u/DEEGOBOOSTER]

I wonder how long it will take for videos like these to be put into Youtubes "Limited State" because they disagree with the content.

[u/Shoninjv]

That was a nice video.

[u/ThisBWhoIsMe]

Evolution is an intelligent design theory, but it offers no explanation of where the intelligence comes from . (Actually it's a falsified theory, falsified by the missing links)

intelligence: The ability to acquire, understand, and use knowledge

information: the communication or reception of knowledge or intelligence

communication: information transmitted or conveyed

instructions; Imparted knowledge

gene: a linear sequence of nucleotides along a segment of DNA that provides the coded instructions for synthesis of RNA, which, when translated into protein, leads to the expression of hereditary character

gene expression: the process by which information from a gene is used in the synthesis of a functional gene product

expression: the act of making your thoughts, feelings, etc., known by speech, writing, or some othermethod 

synthesis: the production of a substance by combining simpler substances through a chemical process

product: something that is the result of a process

process: a series of actions that produce something or that lead to a particular result

gene product: the biochemical material, either RNA or protein, resulting from expression of a gene

genetic code: the set of rules by which ##information encoded## within genetic material (DNA or mRNA sequences) is translated into proteins by living cells. Translation is accomplished by the ribosome, which links amino acids in an order specified by mRNA, using transfer RNA (tRNA) molecules to carry amino acids and to read the mRNA three nucleotides at a time

code: a system of signals or symbols for communication 

translate: to transfer or turn from one set of symbols into another

flagellum

In hurricane Harvey and hurricane Irma, were any new buildings built, or were they just destroyed? There was a lot of random natural selection taking place, we should expect to see a few new apartment buildings and restaurants assembled. Lot easier than a flagellum.