This is one of the most breathtaking facts about life to me...If it wasn't for imperfections, we wouldn't be here. I wonder what humanity's brightest philosophers and thinkers would have deduced from such humbling fact.
A few people have asked about the 'laws of physics' in this video. I'm going have a bit of a stab at expanding on this. The law that is being referred to is the same law that compels Dawkins to keep looking at camera 2 at random intervals. Initially, this resulted in expressions in the footage showing cuts from one angle to another. However, over time, in direct response to pressure from the environment, that expression in the footage has lessoned to a point where we have something stable and that works. We can still see, though, that Dawkins is still 'compelled' to randomly look at camera 2, but because of how the expressions of footage have evolved over time, those random glances are 'absorbed' by the footage and don't have much of an impact - largely, I think, because they don't offer any survival benefit. It is important to note, here, too, that what we are seeing is not a 'final' state, and not the only 'workable' state. These laws seem to be universal, and evolution is never 'finished'. It's entirely possible that pressure from the environment may cause the footage to change again - we may see even see speciation with a new type of footage that just shows camera 2. I hope that clears things up a bit, and that I'm on the right track (honestly, I'm a bit of a novice at this)
but lets assume that there would be a "dna" which replicates perfectly and one that doesn't. Obviously as soon as there are changes in the environment the perfect replicator would die out as it couldn't adapt to the new environment while the imperfect one would most likely adapt. So in consequence, if there ever has been a perfect "dna" then it would have surely died out long ago.
It depends on the change of the environment. The point is that with a perfect DNA replication, there would be no changes in alleles, every individual of the population would be a perfect clone and so if the environment changes for the detrimental, the whole population would die out. But because of the imperfectly copying mechanism, there are different alleles and each individual is slightly different. So that if the environment changes, not all, but lets say 90% of the population dies. The 10% that survived would prosper, mostly because now that so many are dead and gone there is no more competition for food.
***** Ecological niches? You mean that the population of clones could survive in a left over niche? Sure, if one is left. Or you mean how ecological niches are populated? See speciation. One part of the population must become isolated from the main population and under selection pressure genetically drift off of the main population so it can't interbreed any more.
Holz Name Niches, ecological or otherwise. Even if every individual in a population had exactly the same DNA, i.e. were clones, variation in environment may contribute to changes in that DNA within that generation and in future generations, if I'm not mistaken.
MrTruth111 people believing random youtube videos with titles such as SCIENTISTS HAVE TO GO BACK TO THE BLACKBOARD or EVOLUTION DEBUNKED, BUY MY EBOOK NOW in 3...2...1...oh wait that guy's already here^
@@MrTruth111 You mean random RU-vid posters with no knowledge of science have fooled other random RU-vid followers to believe any bullshit that suits their preferred but not realistic views.
these questions are new, look the upload date: march 17,2015, my question is: where can someone post a question so Richard dawkins answers it in a video like those?
Interesting point about how mutation rates persist due to the laws of physics rather than by natural selection, but I'd have to disagree with you here Prof. Dawkins; there is evidence of mutation rate selection among viruses. Even though viruses could easily hijack the host cell's polymerases to replicate their viral genomes, many viruses actually choose to encode their own polymerases with significantly higher mutation rates than the polymerases inherent to the host cell. The thought among most virologists is that the expression of an error-prone viral polymerase helps to increase the rate of mutation, and thus the rate of evolution of viruses. This is one reason the flu virus is able to evolve so quickly. Another interesting tidbit: because the viral capsid is so small, the genome packaged within is often constrained to a relatively small size; there is thus selection for smaller genome sizes among many viruses. This makes it even more remarkable that viruses choose to produce their own polymerases, which are often encoded by massive genes. The fact that viruses would invest previous capsid space for polymerase genes solidifies the beneficial role of mutation rate tuning in viral evolution.
Isn't sexual reproduction a way evolution has "found" to multiply the benefits of mutation while minimizing it's negative effects? Basically, your projeniture gets to "try" a different combinaison of genes but they are genes that have already been "tested" through natural selection.
Hypothetically speaking, if DNA suddenly started replicating perfectly tomorrow, wouldn't we still get diversity because two (essentially random) people's genes would still mix together? We just wouldn't get the random mutations. Is the suggestion that we would eventually, say over a hundred thousand generations, 'average out' our DNA and have a single homogenous group? I think I understand that if DNA had always been infallible then nothing beyond single-celled organisms would ever have developed, but if I have buggered that up too please let me know!
If it's beneficial that mutation rate never reaches zero then why is it trying to get to zero? Is DNA trying to reach perfection, a state where it doesn't need to evolve anymore?
So that means if I keep 0 to 9 digits in a box and if I open it up after millions of years I would get some characters like 'a','d','k'? Or may be 'a' to 'z'? Or even may be a word? A raw image stored can be selectively manipulated to bring variety of formatted jpegs, but not the other way. The more you trim out the details the less you have. You may selectively breed the available details and call it new, and it may look so but we know that isn't the case.
I thought that I heard that it isn't even as simple as mutation in the sense of the DNA code "flipping a bit" so to speak, but that there is a certain amount of jumbling of code segments that also creates differences; so, mixing up of what is already there.
I suppose if there was evolutionary competition between a non changing DNA, and DNA which was "faulty" changing. It is fairly obvious how the changing DNA would come out on top, and force out the Non changer. Is there a philosophical lesson there about perfection ? Most of my best music ideas come from a slip of the hands. If I always played perfectly what I had first in mind, they would not have been discovered.
I'm not sceptical that evolution hasn't stopped, because it can't, but what I am interested to find out is just how much it slowed down, and why that actually is. The first theory that comes to mind is that there is no evolutionary pressure, therefore, the species doesn't have to adapt as much, it's perfectly fine where it is. That seems like the reasonable explanation for (if) the human race for example has slowed down in evolution. But, we just entered an era of genetic engineering, and, quite frankly, it will supersede old eugenics with new genetic manufacturing, and, also to be honest with you, the amount of progress evolution without intention could have made in 3.5 Billion years, is about to pale in what is going to be made in the next 1,000.
I have a question regarding evolution, for a future episode maybe : why do babies cry so much ?We have our brain wired, when we humans are a at their weakest conditions, to cry and alert all potential predators in the surroundings of our presence. It seems threatening to the survival of our species and yet, we still do it. What's the explanation ?
Flojito I would suggest that, as we are primates and primates are usually found to exist in social groups where there is collective care of young, it is more beneficial for a baby to cry to alert the nearest adult that they are in need of attention for whatever reason. Given that many predators use senses far more acute than hearing to locate prey, noise may not necessarily be as risky to survival as, say, lack of noise, where the nearest adults are not alerted.
I think it was somewhere in The Selfish Gene, where he mentioned something along the lines that it's probably just easier to evolve louder babies rather than more caring/aware parents. As for alerting predators, I agree that in social groups, it's probably more important to call the rest of the group rather than keeping yourself hidden. I can see two purposes this can serve: 1. The group can help you, which will often save your life. 2. Even if you can't be saved, warning the group of the danger can potentially save other members of your group, which are likely to share many of your genes.
Another thing that surprises me in this regard is that a sizable part of the population feels more anger than affection towards incessantly crying babies (myself included). That's why you occasionally get these cases of overwhelmed parents or caretakers shaking babies, even to death. Doesn't seem optimal, but I guess it's a tradeoff; preventing negligence is the #1 purpose.
Just my take on this question: Think of DNA as lineages, like phyla - it makes sense that if a DNA lineage stops evolving, then the organisms coded for by that DNA are likely to go extinct either because of environmental fluctuations, an imbalance of competition, or some combination of these factors. Therefore, a DNA lineage with no mutations could be more likely to die out. But then there's differential gene expression, including phenotypic plasticity. If there is enough phenotypic plasticity built into the invariant genome, it could provide a sort of buffer against changing environmental conditions, allowing the DNA lineage to continue. If all DNA lineages stopped evolving at the same time, I the biggest risk of extinction would come from a potentially dominant species - that was previously kept in check by a different (perhaps keystone) species - slowly tipping the scales and eventually taking over, running competitors to extinction and possibly starving itself in the process. Or possibly a virus that is easily transmissible within a species could be released from a competitive arms race with its host species (ie no more Red Queen arms race), allowing it to tip the scales against one or more species, leading to an extinction that could cause a domino effect and tear apart the whole system. Interesting thought...
I'm going to humbly disagree with the statement that natural selection _cannot_ favor mutation. In the immune system, certain regions of immune cells are called *hypervariable* because their genes mutate very frequently. This is favorable, as it is the mechanism that creates random variations in antibodies that are tested against an infection. When a new cell creates an antibody that binds strongly, it is selected by the immune system and reproduced. That was an *extremely* simplified explanation, but the essence of highly mutating genes being beneficial is the relevant point.
You are wrong to say that mutation is minimised to the limits allowed by physics. Surely it is optimised - if a sub-species mutates too slowly it is overtaken by others and mutating too fast destroys previously established traits.
But aren't variations needed anyway, to adapt to different environments such as tropic / temperate / arctic as well as very humid or very dry environments? A phenotype perfectly adapted to one place may be woefully unsuited for another.
Ever since I read 'The Selfish Gene', I had the doubt why does the mutation rate keep slightly above zero, always tending to zero but never reaching there. I personally preferred an explanation a zoology professor in our college gave me: An infallible DNA is very susceptible to extinction, hence it would not survive for long anyway. But I find it embarrassing that I knew the physics before and did not connect the dots. The basic concept is that perfect self replication would violate what is called the 'Law of conservation of information': The origin of patterns in the universe can all be traced back to patterns that were before; that everything is causally related to one another so nothing can be lost.Perfect replication means you cannot establish a point of origin by simply following the mathematical logic; every level in replication can be called a point of origin. Also, the statistical solution of replicators shows that they cannot really perfect the method anyway; the trend would be towards zero, but it will asymptote. Even if conservation of information is untrue, self replicators cannot create perfect copies of themselves because that's the way they are; but a conscious creature may design a perfect replicator. But none has done so to date and no information as of yet is gained or lost.
But what about recombination and crossover events and the like in meiosis? Mutation isn't the only way sequence changes come about -- although I suspect without mutation these things would not be able to compensate enough.
Seems a very human thing to put labels like 'success' and 'failure' onto a repeating chemical reaction, such as evolution describes. It would be better to say that interractions with the surrounding environment increase the likelihood that a particular pattern is repeated, so that's what occurs.
***** But genetic mutations happen due to factors outside the cell affecting the cell, whether it be a deficiency of something the cell needs or damage to the cell.
***** It is, however, the gene itself that PROMPTS the individual organism to try to reproduce. Individual organisms themselves have nothing to 'gain' by reproducing, only the gene does. The gene doesn't always prompt the individual to reproduce either; kin selection, such as sterile daughter bees helping their mother produce more siblings for them, as opposed to trying to reproduce themselves, also passes on genes. The individual organism is simply a puppet of the gene, which manipulates it for its own 'goal'.
***** 'it's the individual organisms themselves which drive evolution', that is putting the cart before the horse. evolution is a result of natural selection. natural selection is in no one's control. animals including humans live and reproduce. evolution is passive. genetic variation is what produces every behaviour in an organism in reaction to it's environment, one way or other. an organism cannot act beyond what it's genes allow. this includes the individual organism's ability to pass on it's gene too. micro and macro is a misleading usage.
MichaelKingsfordGray that just depends on how you define 'artificial'. when you consider that humans themselves are subject to evolution and the laws of nature, there really is no such thing as 'artificial'. it is all natural selection. for the domesticated animals it is just natural selection acting through another species. just like the fungi that grows only on ant farms.
This question "If DNA was infallible" doesn't really make sense if asked like that. It's like the chicken and egg question. Also, it misses out of a vital aspect of DNA which is the crossing over process during meiosis. During cross over, DNA *wants* to be fallible, in the sense that it exchanges parts of the paternal and maternal chromones, and aggressively so; it really wants to be redesigned. Thus, I would also say the "fallacy" of DNA aka being prone to mutations is actually the opposite: A fallible DNA would be one that *never* changes its original form, as it would never be able to bring forth an organism that is adapted to new environmental conditions.
Of course even without mutations there would still be variation through meiosis and exchange of genes on prokaryotes. Evolution would just be limited to existing genes then.
True, but there will no change in the gene pool(as in no information will be added to the DNA) hence the population will go extinct with the change in the environment.
Please like if u agree, What makes us naturally like people like Dawkins is their talent and a lot of fueling from their likable faces..we all are inclined towards pretty things, for example we would want to play with a cute kid over not so cute kid, all though they both are the same species
What we might call genetic defects, do those help provide that variety we need in order to evolve, and are we actually diminishing that variety by only allowing the propagation of genetic traits that we deem desirable?
How are we "only allowing the propagation of genetic traits that we deem desirable"?... I see undesirable people with useless traits popping out kids all the time... In fact, desirable people are relatively rare and probably only make up a small fraction of our genetic propagation... In America, we literally pay the undesirables to have more kids
Sean Woody I was being nonspecific because we do that in lots of different ways, all of which make sense to us as civilized people, but not necessarily as a species.
What i dont understand is and Pardon My Bad english. The atmosphere back then was a Different one than The one from today. So did The Evolution of Species Commit to The Environment because The atmosphere most certainly did not change because of ongoing evolution of species by natural selection. Natural selection and living is only possible if the atmosphere allows it. But I don't know of any change of the atmosphere by natural selection
So, there is something that I don't get it. Crystals are infallible in reproducing their chains? We have some crystal variety, so it can't be infallible too, don't?
Hund Redfire Dawkins compared the too and some hypothesis tell that crystal like structures could have been the first types of genetic organization. So, what do you think? Crystallization has less errors and that's why it has not so variation as life?
Hund Redfire I know that the arrangement of atoms in crystals are simpler than the genetic information. I'm not concerned if it can be read, but if has more or none or fewer error as DNA.
“The only reason that mutation rate doesn’t get to zero is because of the laws of physics”. That might be true, but it seems like one of those dogmas that merits more investigation.
***** There are levels of perfection. You say Heisenberg's Uncertainty principle as though that prevents macro replication, yet manufacturers manage to duplicate phones that work just fine. If DNA is above the level where "uncertainty" makes a difference, I don't really see how that applies?
Hund Redfire Thank you for your invaluable contribution to the conversation. Were you also the kid who put up his hand to tell the teacher he DID NOT know the answer to questions? What a little attention seeker. Sigh.
Hund Redfire Please accept my apologies. Your terse answer made it appear as though you were being sarcastic. Thank you for the fuller response - much more informative.
Add cosmology in there as well. Cosmic rays hitting the germ cells are known causes of mutation, and being a germ cell that gets hit means that change is passed on to the offspring for selection to work with.
If one species had a mutation rate of 0, thus cannot adapt at all no matter how much time passes (it can't even mutate to a state where it mutates again, for obvious reasons), and one species had a very low mutation rate, the second species could adapt. If then some gradual geological shift happens, only the species that can adapt will survive long-term, while the other species only had its advantaget previously, when its lower mutation rate meant fewer early deaths due to malformation. But long-term, which evolution is all about, the one with no mutation HAS to be weaker. How would a dinausaur fare today, for example? Probably not that good I suppose
The faster that creatures die, the quicker they can mutate as a species. So, did natural selection actually choose features that lead to death, over immortality... as a survival feature?
He's looking at the second camera. You can see footage from it in one of the previous two question videos. Why they chose not to use any footage from it here, who knows.
The thing is this is all prerecorded . They can only edit it either with camera switching or with one camera but dawkins looks away every once a while . Annyyy way i'm here to hear what he has to say not to see him look into a camera
We All Have different like and dislikes, to me and many others even Evolutionists scientists know that DNA is like a blueprint, of what we will turn out as a person ,eye colour,hight,etc,that we inherit from our parents ,therefore the Question comes up ,why do we die,why do we go to the grave so early ,when it looks like we are designed to live longer ? The answer goes back,did some thing go wrong in Mankinds start in life ? Answer, Roman's 5:12 DId or was a law broken that up set that blue print, and that's what we have inherited as a human race ?
I am not trying to be racist and have been trying to get rid of the idea of race. But I shall not deceive myself. I wish to raise a question or two. Has the appearances of different races and ethnicities got anything to do with evolution, and are different races the key for humans to split in the evolution chart? And also, what is the effect of inbreeding on evolution? But we still are all cousins.
+George Severn Yeah, kinda. It is still decent with modification but we are not different species because part of the definition is that we can have viable and fertile offspring with any other human on Earth, ergo the same species. The differences arise due to adaptable mutations: less melanin and the presence of lactase in N. Europeans to compensate for the lower amount of sunlight which would lead to a Vitamin D deficiency. People in Asian developed the bit of skin around their eyes to protect them from the wind. Humans that stayed in Africa developed even more melanin to protect from harmful radiation. Etc. It is completely expected if you have isolated populations that are geographically isolated for a long period of time for independent mutations to occur and then for some of those to be beneficial and become widespread leading to the physical variance that we observe. I think that it is perfectly possible that given enough time two groups of isolated humans would evolve into different species and would become unable to produce offspring with one another (imagine the sperm have a mutation on one of its receptors that no longer allows it to interact with the egg of something).
On the premise that DNA is infallible would not therefore lead one to conclude that there would be no diversity. The DNA would still be able to mutate, though the mutations would not be random. Humans do not use natural selection, so natural selection is not intrinsically linked to evolution. The species would still evolve. DNA is nothing more than a program, if you think of it like a computer program that can reprogram itself in order to suit its environment, then that would be an infallible program. There would still be diversity and there would still be evolution. Its ability to reprogram itself would make it infallible.
Strongly disagree! It’s not about physics laws. Evolution did favor the DNA copying process, with the right degree of mutations needed to propagate effective variation. Other comparative DNA copying processes with too many or too little mutations did not survive to tell the tale. We are merely witnessing the one of many processes that was robust enough to carry out evolution to this day.
Dna is comprised of a large string of four different nucleotides. Though this string replicates with very high accuracy, it is possible for a single nucleotide to be replaced by another while retaining the replicating nature of dna and the stability. To put it this way, for this not to be the case, it would mean that there was only one possible stable bond, that there wouldn't be any other molecule that could fit in there without jeopardizing stability. A big takeaway from chemistry is that that are many different ways to arrange even the same atoms into a stable configuration. Since there are different possible bonds, even if the bond is very unlikely to occur, every one in a while it will occur just by happenstance.
choo xing yu You're best reading this if you want to know what causes changes in DNA: en.wikipedia.org/wiki/Mutation#Causes . The reason Dawkins used 'laws of physics', is because basically everything is beholden to the laws of physics, as biology is a subset of chemistry and chemistry is itself a subset of physics. It's all a matter of scope.
It is at least possible that random mutation never reaches its physical minimum because DNA that does mutate has a higher chance to produce a reproduction mechanism (a biological organism) that will survive shocks. The more resources go into the development of the reproducing organism the less mutation is present because fatal mutations become more costly to the species as a whole. DNA proofreading proteins are evidence toward that assumption. While very simple organisms can afford to allow for more mutations as a single individual of the species does not represent a significant investment of resources. The longer a species keeps a similar ecological position and shape the less mutation occurs as strands with better copying accuracy are more successful and mutants die out. This is at least my guess.
I wonder if we - humans are "messing" too much in our evolution process? Like with dog breeds there are some breeds that are unnatural or even harmful for ex. buldogs can't breath, we also pass on some genes that in a natural selection would extict by now because everyone can have kids. I for ex. do not have or want kids but I have a genetic condition called Ehlers Danlos syndrom. It's only "usefull" if you're a dancer or a gymnist but I'm a psychologist and it causes me a lot of enjuries and pain. I was born with a defect of both hips and if I was born as a zebra I would be eaten by a lion by now. Because I am a human in a civilized (more or less) country I have potential to pass that awful genes.
I'm just confused when thinking about how a reptile could give birth or spawn into a birds or mammals or apes. please explain in detail or at least make me understand how it works?
Science and magic are the same thing, like two sides of the same coin. When Dawkins says DNA, what he really means is 'soul' and when he says mutation what he really means is 'polymorph' and when he says extinction what he really means is 'power word kill'. The ancients at Lake Geneva knew all this.
A common misconception Sandwich247. DNA is what makes a person a person, as the same way a soul also the essence of a person [1]. This essence is a code, the same way your soul is the code, copied from the code of the supreme perfect being of which we are just shadows, i.e. natural selection [2]. I studied for years to become a sixth circle evocationist and third circle abjurationer. So I understand these subjects at a much greater level than you. 1: Book of Vile Darkness 2: The Republic - Plato
Totally wrong, if DNA was infallible we would have less illnesses and malfunctions but STILL we would have variations. Variations have nothing to do with mutations. 99,99999999999% of mutations are harmfull. Luckily our cells have sophisticated error checking and repair mechanisms. Mating is the way to go for variation. We look (and animals too) for healthy partners, we don't look for mutations. They claim birds evolved from reptiles, but I don't think a reptile with a bunch of feather stumbs would make it a disireable mate.... Btw, how is the information theory debunking going on Dawky? Any luck yet? Figuring out how to trick people with another bait and switch?
What if a million other things that also aren't the case? You see how just saying "what if" by itself is meaningless and thus pointless? There needs to be something more than saying "what if" something is actually not what it appears to be; otherwise there's nothing there for anyone to care about or do anything about.
Then where are all the transitional creatures today? If evolution started wouldn't it be an ongoing process? If we have been here for so long we would be stacked 5 high by now, look at the population increases just in the recent centuries. Oh, and why the heck did we evolve to need shoes.....oooops!
