Secrets of the Cell with Michael Behe (Season 1 Compilation)

[Music] machines they enable us to be creative and produce spectacular structures we also find magnificent structures in nature and each of these living structures was also built by machines machines that are far more elaborate than anything that humans have ever built in fact this log is currently being decomposed by tiny fungi that are vastly more complex than this drone i'm mike behe welcome to the unseen world of organic micro machines every living thing in the world is made of cells microbes are single-celled organisms advanced life forms have trillions of cells inside a cell is a bustling operation of interconnected molecular machinery so sophisticated it would put any modern high-tech factory to shame this intricate machinery is what gives the cell its remarkable abilities to process energy execute genetic instructions and replicate all with unbelievable efficiency i'm a biochemist a scientist who studies the molecules of life there's never been a more exciting time to be a life scientist this is a golden age of discovery in molecular biology stunning breakthroughs in our understanding of the most fundamental unit of life the cell have been coming faster and faster [Music] my own view of the cell took a turn years ago i was in a lab at the national institutes of health doing postdoctoral research i was discussing the origin of life with a fellow postdoc as she and i thought about the cell we wondered how could its complex membrane proteins metabolism genetic code how could all that have formed by the accumulation of undirected changes so we were both sort of stunned by the notion but then we just laughed it off we figured that even if we didn't know the answer somebody must know well in the 10 years after that i didn't come across any science publications that adequately answered the nagging question exactly how did the cell get to be so complex everything i read presumed that those biological mysteries would eventually be solved by darwin's theory of evolution being an evolutionist myself that was fine with me then i came across a book titled evolution a theory and crisis by a geneticist michael denton it addressed profound problems with darwin's theory it asked hard questions about the origins of life and it showed that science didn't have the answers no matter that everyone assumed it did or assumed that it would eventually or something i was flabbergasted by the book i began to look at biology with a fresh set of eyes and i started asking questions lots of questions that's what this series is about asking questions not about the why or when but about the how of biological origins [Music] as i said there's never been a more exciting and fun time to be a biologist so i'm really looking forward to jumping into this series and i hope you'll join me [Music] we all love cars for their beauty and performance but except for guys like these not everyone really understands what's inside [Music] is this what you're looking for not even close you could stand over there oh okay i'll just stand over here in a way cell biologists are like auto mechanics each cell has an astonishing number of intricate parts way more than any car we study what the parts are how the parts work together and even which parts of the cell can be left out without causing too much harm if you understand the inner workings of the cell you can understand a lot about all living things what makes them thrive what makes them fail and what causes them to evolve we'll cover more about that later right now i want to look at the topic of complexity [Music] you and i are made of about 40 trillion cells they comprise every part of our complex human anatomy but the truth is that we can reduce the number of parts and still have function if we lost an eye an ear or a hand it would be very unfortunate but our lives could go on the same applies to this rather complex drill it has some cool add-ons but i could take off this battery gauge through this led light for a few other gadgets and i'd still have a working drill but how far can i reduce its complexity and not ruin it i don't want to take apart my drill so let me move to another example this mousetrap the complexity of this machine entails five parts the platform the spring the hammer the holding bar and the catch now if i reduce the number of parts from five to four if i take away the holding bar or the spring or any other part it wouldn't work every part is essential i call this irreducible complexity so does this apply to biology too do we have examples of irreducible complexity in life try this one here's a bacterium a single cell microbe some bacteria have a flagellum which is like an outboard motor on a boat it rotates to propel bacteria through liquid and it's necessary for their survival in order to swim to search for food the flagellum has a number of parts a drive shaft a universal joint a rotor bushings stator even a clutch and braking system the motor of the flagellum has been clocked at a hundred thousand revolutions per minute and as with the mouse trap removing even one component of this elegant machine destroys its function and renders the bacterium shall we say dead in the water the flagellum is irreducibly complex now we know that this was assembled in a factory but how is the bacterial flagellum developed in nature keep in mind the flagellum is irreducibly complex all the parts have to be in place or it does not work could it have been developed blindly in stages let's say in the distant past the bacteria first gained a drive shaft later on a rotor then a stator and then the rest then the parts got in sync as a high performance engine the theory of evolution tells us that given enough time any organic structure we see today no matter how complex could have slowly and fully developed by random unguided forces we'll come back to the topic of complexity in our next video which will examine the power of evolution we don't typically ponder the elegance of bugs especially the annoying ones but scientists and engineers have come to realize they are actually mechanical marvels nothing we humans have ever built even comes close in fact a growing field of engineering called biomimetics is making breakthroughs by mimicking biology for example studying the eyes of flies led to the development of advanced optical sensors the physics of dragonfly wings allowed increased efficiency of wind turbines cockroach mechanics paved the way for increased agility in robots a honeybee algorithm helped to optimize the internet and the tiny plant hopper is helping scientists to maximize the strength and rotation of gears what gears in a bug that one got my attention i thought humans invented gears those perfectly precise interconnected drivers that have transformed machinery for centuries well it turns out that biology is far ahead of our engineering the plant hopper launches like a rocket and can jump more than a hundred times its body length that's like an olympic long jumper hurtling across not one but two football fields using special cameras scientists at cambridge university discovered that the planthopper coordinates the motion of its legs with these incredibly precise gears making long leaps accurately requires that the legs be in perfect sink if one leg flexed even a fraction of a millisecond before the other the insect would lose power and tumble erratically as one leg begins to move the interacting gears start the other leg too with the teeth engaged the gears spin at a whopping 50 000 teeth per second and the bug is propelled with maximum power and coordination as science learns more about the structures of living organisms we seem to be finding limitless examples of mechanisms that are both precise and purposeful both remarkably configured and beautifully functional so what accounts for the stark purposiveness of the machinery of life for over 150 years evolutionary biologists have thought they had an explanation darwin's theory of evolution darwin proposed that all life evolved simply by variation that occurred within a species then natural selection determined which one survived for example let's look at bear evolution scientists believe the polar bear in the arctic evolved from ancestral brown bears in adjacent regions here's a possible scenario many thousands of years ago a bear cub was born with a mutation in its dna the change gave the lucky bear the ability to eat a high fat diet like seal blubber so the mutant bear and its descendants could hunt seals for food generations later a baby bear was born with another mutation that altered its color the subsequent change from brown fur to white was useful in the snowy environment for sneaking up on prey more such helpful mutations followed so variation in the ancestral species of the brown bear followed by natural selection for the harsh snowy surroundings were responsible for building the magnificent polar bear in small steps we can see fascinating evolutionary changes in species but modern science now know something that darwin didn't know that the changes in the species that we can see are driven by molecular changes in genes and dna that we can't see at least not with our eyes now for a few sixty four thousand dollar questions what precisely are those helpful mutations in dna how exactly do genes change if brown bears can give rise to polar bears does that mean we'll see future genetic changes making new species will we humans mutate into super-powered [Music] x-men we'll open that box in our next episode on the effects of mutation [Music] dogs are easily one of the most diverse species on earth geneticists tell us it's likely that each of them descended from one animal the wolf these breeds look very different from each other but they all share much of their dna with those early wolves and that's what makes them dogs now let's move inside the cell and see how this works dna is found in the nucleus of the cell it consists of a long chain of chemicals designated by the letters a g c and t some sections of dna are called genes they contain the specific instructions for making the proteins that form the cells that give the dog its traits in our last episode we saw that dna in brown bears had mutated to form polar bears well how does that work a mutation in a gene occurs when there's a change in its sequence often this results in breaking one of the instructions for forming the animal in this case the mutation was in the specific gene that determines fur color the disabled gene is unable to give instructions to make colored fur so the mutant fur is white the change in bears occurred long ago wouldn't it be great if we could observe mutation today in real time well we're in luck critical work has been done in the laboratory of richard lenski who worked with a species of bacteria called e coli the lenski lab has been growing generations of e coli and flasks for 30 years in the early 1990s they saw that the descendant bacteria began to grow faster than their ancestors that was great news for the happy e coli but why was this happening a decade later they were able to determine the mutation that caused it what they found was that a certain gene in the e coli had been destroyed losing that gene ended up helping the bugs grow faster [Music] then they looked at a dozen other helpful mutant genes in the e coli and saw that they too had been broken mutations had left the genes either crippled or completely disabled but that seems odd how can breaking a gene help the organism imagine you have to drive to a destination on one tank of gas or you'll die given the weight of your car you'll never reach your destination on just one tank so you toss out the hood a seat floor mats and the cigarette lighter the lighter degraded car gets you to your destination and you survive [Music] so breaking genes can help e coli adapt to a lab environment and broken genes help the polar bear adapt to the arctic how about our dog friends in just the past 20 years scientists have actually discovered many mutations responsible for traits of breeds and again the mutations don't construct new genes most of them break or damage pre-existing genes for example increased muscle mass in some breeds derives from degradation of a myostatin gene we also know what mutations caused a yellow coat short tails even the lovable friendliness of dogs towards humans compared to less friendly wolves so a dog can be changed by breaking genes but it comes at a high cost the broken genes very likely will never return to their original working state the dachshund with short leg jeans won't be returning to anything resembling a labrador and we won't see the polar bear mutate back to its old self eating berries [Music] in short helpful mutations are not a dna upgrade getting a newer smartphone is an upgrade it's more helpful because it has completely new features but mutations don't install new features in dna they only make changes to existing ones a mutation is more like disabling your gps it may help to save your battery but it doesn't add a new function we're told that random mutation is the main driver for evolutionary change and that evolution is responsible for lower forms being upgraded to higher ones yet the latest scientific results show new species are made by breaking genes by devolution not evolution is there another piece of the puzzle that we're missing is there some unknown some x factor that boosts the capacity of evolution to gradually generate higher and higher life forms i'll let you think about that for a bit and i'll see you next time when we discover the x factor [Music] [Music] [Music] as we search for the x factor that accounts for the complexity of life we have to follow the evidence so what have we seen so far [Music] let's begin with the cell what was a mystery to charles darwin is now well understood we know that the cell encodes and transmits information that regulates the size and shape of living things and we know the cell is comprised of insanely complex machinery what's more much of it is irreducibly complex all the parts are necessary in order for an irreducibly complex system to work irreducibility is evidence that all the parts were formed intentionally with the end purpose in mind not randomly over time finally darwin's explanation for complexity was evolution where random small variations over many generations progressively led to life of greater and greater sophistication but science has just recently discovered that variation comes from genetic mutation and that even helpful mutations usually break genes that's not evolution that's devolution so what is the evidence for some x factor that accounts for biological complexity let's think about it if you were to come across this formation for the first time what could you conclude from examining it there's no apparent evidence that shows when it was made who made it or how it was made but we do have clear evidence that it was not arranged randomly it was planned by an intelligent being the purposeful arrangement of parts that is the way the only way that we recognize the work of a mind and the more intricately the parts are arranged the stronger the evidence that a mind was at work the x factor that accounts for complexity is intelligence an intelligent being is responsible for much of life the exquisite and purposeful design found throughout nature is overpowering evidence you might say hold on a second don't we have to see the arrangement being put together to decide for sure that it was done on purpose after all we can see how an intelligent builder constructs a home if we can't see or understand how design occurs in nature why should we believe there is an intelligence behind it well it's what we can see that is the whole point [Music] suppose three visitors from a distant place stumbled across this surprising stone configuration that they had never heard of before not knowing how it was formed one visitor might think it had been chiseled the second guesses that power tools were used the third might suppose it was cut by lasers but none of them would conclude that mount rushmore was formed accidentally through gradual random erosion by wind and rain they would immediately know it was purposely designed just by perceiving the intention behind the work the purposeful design of nature was nearly universally held common knowledge for millennia some thinkers such as the philosopher aristotle believed that purpose was built right into nature others such as galen the esteemed physician in rome thought that purpose had been added to nature but almost everyone educated or not religious or not realize that life was intentionally designed going beyond biology other fields have acknowledged purposeful design through the ages astronomy chemistry and physics all reveal arrangement and order science took a detour from that strong consensus when charles darwin proposed random unguided evolutionary causes now we know that darwin was right for the case of small changes in life but the void of evidence for large random evolutionary changes supports the enduring consensus of purposeful design so who is this mind one thing we know is that it must be phenomenally intelligent to be able to design life what's more a mind is at least as intelligent as its work has shown it's likely much more intelligent [Music] but it's clear that errors do occur in nature babies are born with birth defects good people get cancer why as i said earlier i count myself among those biologists who think that science alone may not be able to answer the question of who or why perhaps philosophy and theology are needed for that but the identity of the designer is a separate question the bottom line is that just like those travelers encountering mount rushmore for the first time we can see the evidence if we carefully study it we can know with certainty that life was designed by a mind [Music] in this short series we only scratched the surface of the topic of the elegant purposeful arrangement of the parts of the cell and how that points so strongly to a mind but the discussion continues on the series website please go there for a deeper look at these topics finally thanks for watching this series i hope it has expanded your own appreciation for the elegance and design of nature [Music] you

Channel: Discovery Science

Views: 73,512

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, Evolution News & Views, Michael Behe, William Dembski, John West, Jay W. Richards, Darwin Day in America, Darwin's Black Box, Privileged Planet, Icons of Evolution, evolution news

Id: gw94qm4qdn8

Length: 29min 18sec (1758 seconds)

Published: Tue May 03 2022