Mutation Bias: Were We Wrong About Evolution?

Stated Clearly Patreon Page / statedclearly
Are mutations truly random? Yes-but not in the way you might think. In this video, we break down what scientists mean by "random" when talking about mutations and why it’s a bit more nuanced than you might expect.
While cells don’t decide which mutations they want next and then actively cause them, mutations don’t occur with equal probability across the genome. Factors like DNA’s physical structure, repair mechanisms, and (this is currently debated) even past selection pressures can influence mutation patterns.
Recent research suggests natural selection might shape these mutation biases, shaping genome structure to prioritize protection of vital genes-much like how your skeleton evolved to protect vital organs. But how much do these biases influence evolution?
FURTHER READING
Paper on mutation bias (featured in this animation) www.microbiolo...
Paper on a mutational hotspot in Bacteria: www.nature.com...
STATED CASUALLY VIDEOS
As mentioned, I have a series of videos on the papers claiming to show that mutations are not random. Here are links to those:
Essential genes (and random mutations) • Do "Essential Genes" d...
Are Mutations Random? • Are Mutations Random O...
What to make of non-random mutation in Arabidopsis thaliana? • What to make of non-ra...
SPECIAL THANKS
This video includes footage of old Soviet technology provided by the wonderful KZbin channel ‪@ChernobylFamily‬
Check out their work!
CORRECTIONS
We got a technical correction on the deamination diagram from viewer, @johnathancorgan3994:
Nicely done. Very minor nit: the cytosine structure is missing a hydrogen, and the uracil has an extra bond between the carbon and nitrogen

[@kventinho]

Genetics PhD here. I am just so blown away by this video. I didn't even think I personally could have condensed this concept so succinctly and so clearly as you did. The DNA toy is such an amazing teaching aid that I've never seen before (and uni professors SHOULD consider using this for lectures) and the way you perfectly tied the stochasticity and probability of mutational events to statistics classical example (rolling dice) is actually pretty cool. I never really thought of them this way before but it's definitely apt!

[@StatedClearly]

I think that's the nicest comment I have ever received. Thank you!

[@igorjee]

As another biologist, I couldn't agree more.

[@Frostyflytrap]

Phenomenal Stated Clearly video! I just learned that mutation hot spots/cold spots exist, and the use of physical models for demonstration was very intuitive and mind blowing!

[@calebr7199]

I love that frog eating those leaf bugs animation, such a good short visual example of predator selection

[@matterhorn731]

*Chameleon:* "Good sir! I am no frog! I am an amniote, same as you!"

[@calebr7199]

​@@matterhorn731 Oh, it was a chameleon! lol. I was so focused on the bugs I thought it was a frog!

[@koppite9600]

@@calebr7199 Depends on the vision on the predator. Camouflage may work on us but not on other eyes

[@Pottyde]

Yeah, so cool. The chameleon forgot to evolve better detection though... Pesky not-so-random chances.

[@ChernobylFamily]

Oh wow! It's a great honor to see our tech in your video! Thank you and all the best!

[@StatedClearly]

Thank you! I was just about to send you an email to let you know the video is up!

[@ChernobylFamily]

We'll write you tomorrow. We see some interesting ideas on collaboration in the scope of genetics and so.

[@thejesuschrist]

This was explained exceptionally well. Great work!

[@StatedClearly]

Thanks, Jesus!

[@atptourfan]

These are the best videos out there on evolution theory.

[@Lardzor]

@1:38 " but it can't be swapped out, with say, an elephant or a tesseract." - Citation needed.

[@ayybe7894]

You CAN substitute any specific base pair with an elephant.... once.

[@blzrdphoto]

No Citation Needed when it’s been “Stated Clearly”!

[@stm7810]

Timelord DNA be like:

[@PasseScience]

One of the most fascinating mutation mechanisms skeptics of evolution should consider is the process of copying and specializing entire genetic sequences. For example, when it comes to developing sensitivity to green light in addition to another wavelength we already perceive, evolution doesn’t need to start from scratch. A random duplication of the existing gene, followed by the independent evolution of both the original and the copy, can easily lead to a new, improved color sensitivity with an additional color. This "copy and specialize" process is an incredibly powerful tool in evolution, allowing complex adaptations to arise in just a few steps-what might otherwise seem almost impossibly unlikely.

[@koppite9600]

How does it know to keep it that way? Is it intelligent?

[@ayybe7894]

@@koppite9600 No, that's what natural selection is. Genes are just instructions for making cells, and get passed on. If there's a mutation that gives a beneficial edge, then that organism is more likely to survive and reproduce, and that mutation spreads. Rarely would any one mutation be enough to give a huge edge to any specific animal, so realistically a mutation just needs to not be very harmful, and then a bunch of smaller mutations can build up and accumulate to something that IS a huge advantage over time and many generations. This video showed the example of a slightly green bug evolving into a leaf over many, MANY generations, making tiny incremental steps towards being a leaf-bug by virtue of just getting eaten less.

[@ragg232]

​@@koppite9600It "knows" because of the nature of the molecules that make it up. (And by extension the atoms that make up those molecules) Fundamentally those molecules stick to other molecules of the same type. Similar to how a magnet will stick to another with one or more of the compatible poles facing each other. In fact, on the atomic level, they're held together by electro magnetism.

[@valkyrie283]

One of my skepticism about evolution goes back to the beginning. For sure current forces don’t have to start from scratch, but way back at some point they did. Now, I say skepticism because that’s just it, I’m skeptical. I think evolution is entirely possible, but I’m just skeptical of a lot of the theories based on the current evidence we have, and a lot of times I’m put off by the dogmatic adherence to one theory or another I run into a lot when evolution comes up in conversation.

[@emptyshirt]

@@koppite9600 If cells evolved any way of marking important genes as priority targets for repair or duplication that could be advantageous. Since cells routinely mark genes for promotion and supression useful genes are already easy targets. Any method of prioritizing gene preservation would improve fitness of lineages where the important genes are favoritely repaired, or copied. Priortizing the wrong genes would be disadventageous, so prioritization would tend to drift towards positive prioritization. That is how the "knowing" could evolve.

[@WillPeterson]

Bro, these models and analogies are so clutch! Thank you for explaining so clearly

[@Trucmuch]

This is a great video and so useful. When you see how the word "theory" is often twisted by people who want to deny science, it is important to clarify what "not random" actually means. To be honest, I think it's a poor choice of word (if not clickbaity) from the authors of those papers.

[@celltoself]

An excellent, informed summary of a complex topic carefully communicated. Thank you!

[@danielduvana]

This was a really good explanation of mutation bias! I’ve heard about this a bunch and knew the basic idea that it’s random but uneven distribution - however I had no idea about how different parts of the genome could be differently prone to mutation. Loved the demonstration you did

[@HeadCodeMonkey82]

You have a very effective teaching style. It made me realise my mental model of mutations was simply "radiation", I never imagined that the cell machinery itself could cause them. And thank you for the dice explanation for biased randomness, I expect to make a lot of use of that when explaining things myself.

[@FailSpace2]

This is seriously one of the best videos i’ve seen from this channel. the physical magnetic model simulating cruciforms is really helpful, along with the animations. Thanks a ton for educating us on the awesomeness of evolution!

[@Jaggerbush]

Ive waited a year for this!!!! I've never unsubbed - just waited for something other than a short. 🎉🎉🎉

[@bazoo513]

Random events don't necessarily appear with linear distribution of probability. So, using the word "random" for mutations is perfectly appropriate. (Edit: Duh! I did it again - commenting in the middle of watching the video. You said this two seconds after I hit "Send".) BTW, your wooden model of DNA is ingenious and _extremely_ illustrative. Great work - stated clearly indeed!.

[@denki2558]

It also shocks me when I have to remind internet peeps that random doesn't only mean uniform random. Happened twice this week on different forums.

[@peterbrockway5990]

Wonderful video. 2:50 "Random does not mean however that all mutation types are equally likely." As noted at 9:33 mathematicians have a notion of a _uniform_ distribution where all possible values are equally likely to occur. A given random distribution may or may not be uniform: it's a different concept. Back in the olden days English used to have things called _adverbs_ and we might say, with more clarity, that heritable mutation occurs _randomly_ without committing to any specific claim about the distribution of the changes except that the organism did nothing to alter that distribution.

[@blaster-zy7xx]

There must be something floating around in the creatard world. I just received a claim by a creatard that mutations are not perfectly random and therefore falsifies evolution. I explained this exact concept more than once. Pearls before swine.

[@kf1000]

It makes sense that the dna itself would select toward having certain critical parts be more protected against mutation while other parts be open to mutations.

[@Dr.ChrisThompson]

Your videos are truly outstanding, and this is just another top notch contribution. I really appreciate how much effort you put into each one of these. And I always learn new things in each of your videos. Please keep up the fantastic work!

[@user-sb3wh3dd4v]

Excellent explanation! Great graphics. Good ( not boring ) narration! Liked and subbed!

[@ismailcalsr2226]

so happy you're back!! love your videos

[@AustinThomasPhD]

"Mutation is stochastic" is probably a more accurate statement than calling it truly random sensu stricto. It follows some general (though highly complex) patterns overall, but individual mutation events in individual gametes or somatic cells can't be predicted with high certainty.

[@johnathancorgan3994]

Nicely done. Very minor nit: at 11:40 the cytosine structure is missing a hydrogen, and the uracil has an extra bond between the carbon and nitrogen.

[@StatedClearly]

Ha, you're right! We need you on the review team.

[@StatedClearly]

FYI, I added a correction in the video description crediting you. Thanks!

[@DrZedDrZedDrZed]

Fantastic video, thank you for continuing to put out fanastic educational resources for so many years! Please don't stop!

[@nathanmartin2277]

This is a great video. I thought this was going to be about selection bias. We don't observe a lot of mutation to HOX genes (because mutation to those genes terminate the embryo). This was so much more interesting!

[@kellydalstok8900]

During the late 1970s and early 1980s I used to work with a vintage Burroughs machine that had to be programmed with the same kind of punch tape for every different task. Depending on the task this could take quite a while. Luckily they didn’t randomly mutate, but they could tear.

[@maartendj2724]

I was gonna say that random is not necessarily "anything can happen", but you explain this at the end. Great DNA model!

[@fastechx]

Great video! What do you use to create these? I want to create science videos too like yours in different language.

[@chrisray1567]

This channel is so underrated. It deserves to have millions of subscribers.

[@sorry6726]

Finally one of my favourite channel posted a video. I downloaded your videos in the past and showed them to some students and core creationists. And it was positive for them to take science in a better position than before.

[@whlewis9164]

So glad I found this channel. You are killing it, my friend. ❤

[@ericsilva6787]

This was incredibly well explained!

[@jasiekthejester7764]

It's a soothing sight to lonely eyes seeing a new video on your channel! Hope it's just a warmup! 😍

[@jaschabull2365]

This takes me back to my days as a college student just learning physical anthropology and general biology. Pretty neat to hear!

[@arashputata]

and that's why kids, a biologist must be good at probability and statistics! The concept of probability distribution is the key!!

[@possamei]

Really clear explanations with some intuitive vsualizations and analogies! Thank you for making this, it was really informative.

[@ytunnuyt]

Brilliantly made video, keep on the good work

[@BoneAppleTea]

These videos are great! Very detailed and easily understood. Schools should use these in biology

[@DouwedeJong]

Thanks for making this video. It is very informative and I learned something today.

[@torinmccabe]

One of my favorite misunderstanding of randomness is creationists who say certain DNA sequences are so unlikely as to be be impossible / God did it. They often rely on the false premise that you have to generate the entire sequence all at once rather rather than the actual process of small changes being built up over time.

[@Angelmou]

Another misunderstanding of most creationists is that they confuse the term randomness very often with "lack of meaning/sense of life" feelings in many cases as they approach the topic not with reason. An example I like to give is where you explain that the interlocking of complexity of water droplets to hundreds of snowcrystals follows specific nucleation mechanism for certain crystallization - it does not randomly snow at a hot summer day without even a cloud in the sky. Deniers of science of crystallization (or gain of complexity in nature) either demand snowpixies for snow to exist or they complain about when we talk about that we observe some snowflakes to immediately cease to exist again when they hit a hot tin roof or fall into a chimney to evaporate how "meaningless" or "void of sense" it would feel. They can't then debate even the stochastics behind. Like they do not want to face for emotional reasons why humans are just 1 mammal species among others. This means that some day humanity most likely shares the same fate like 99% of species of the past incl. many mammal species before (like the wolly mammoth) and just ceases to exist. So without a further plan or goal of an assumed planer "behind the curtain". Which causes there the major anxieties.

[@JohnSmith-ik8nt]

Which you still don't have evidence of it's beginning, while God exists and he told us how to live

[@Angelmou]

@@JohnSmith-ik8nt We have several research bases how DNA mechanism came to be with RNA reductasis like Uracil to thymine (5 methyl uracil). Deities are envisioned as thoughtorgan & especially thoughtprocesslacking thinkers. Like some people envision squared circles, as well. Since when are men-made guesses about vaporous minds without bodies (and specific organs) specifically male in their gender btw.? So a "he" did not tell anything to anyone. We have menmade texts, which are claiming to speak in the authority of the concept of at least 1 god (1 thoughtorganlacking thinker) mostly due to false advertisement for those texts. In reality the menmade texts even have the audacityto claim the numbers of those asserted vaporous noncorperal entities, beside their gender and whatnot.

[@rizdekd3912]

@@JohnSmith-ik8nt At least people think God exists and told us 'how' to live. So...we still don't have evidence of 'its' beginning.

[@FinalMorningstar]

mutations have never been shown to create new limbs, or parts, just adaptations on the existing ones.

[@dongeonmaster8547]

Great video. I love this series.

[@mrapistevist]

Good video. Good example.

[@bigmac8574]

Very good video. Thank you sir.

[@capivara6094]

Babe wake up, new Stated Clearly video dropped

[@bazoo513]

3:56 - Not directly relevant, and it appears that this actually was from a Soviet computer, but I used punched paper tape on, among others, Hewlett-Packard HP-2000 and Data General Nova 1220, both American computers. Before that, punched paper tape was routinely (and globally) used in telex machines ("teletypewriters"), successors to telegraph and predecessors of fax and other more modern means of communication.

[@WorthlessWinner]

They're still random with respect to fitness effects

[@welcomewonder1604]

Hmmm. Not an expert, but I think I read a while back that the mutation cold spots have been selected for, such that they tend to protect the more fundamental cell/organism functionality. So I think in terms of deleterious mutations, mutation bias actually does influence the danger posed by mutation to the fitness of an organism.

[@StatedClearly]

Mostly.. see my video on the Arabidopsis paper. I do think Monroe is correct to say that this catch phrase is misleading. Over time, it seems that natural selection can put essential genes in cold spots. kzbin.info/www/bejne/b4C9ZH2BqbSIZ80

[@anirban7493]

Ah finally a Ctated cleaarly video after so long💙

[@anthonyvachon2337]

Hey Jon, where can I find the magnetic model of DNA that you briefly showed in this video? Thanks!

[@StatedClearly]

I made it, so there's only one.

[@StatedClearly]

I'll make a video showing how to make them. It's a bit more time consuming than I'd like.

[@talkpopgen]

Excellent and timely video! Mutation bias ~is~ such an important component of evolution, but boy is it easy to sensationalize into obscurity.

[@StatedClearly]

Yes, this is exactly why we made this video! I wrote Tiffany trying to get her view on how big a deal mutation bias really is (vs the hype), since she's one of the leading experts on it. She had the same frustration with the media hype that I had. So much so that she funded the animation!

[@tophers3756]

I don't think this could be explained any better to the average person. That includes me.

[@stowcreek1999]

Awesome video!

[@Hansulf]

The kind of videos KZbin needs.

[@blzrdphoto]

This video blew my mind. It never occurred to me that DNA could “accidentally” stick to itself. I am very interested in that magnetic DNA model. I bet my kids would love it.

[@StatedClearly]

I made it in my basement. I'll have to find a company that wants to mass-produce them.

[@blzrdphoto]

@ until then I might have to break out the hot glue. Sounds like a fun project.

[@ayybe7894]

@@StatedClearly a "neat toy / demonstration that is time consuming to manually create" seems like the perfect thing to try and 3d print. I am sure at least several viewers would appreciate a printable 3d model on thingverse!

[@abrahamziga159]

I would like to buy a magnetic DNA model for me and my childrens​@@StatedClearly

[@Snakeyes244]

This was excellent! Thanks

[@matswessling6600]

eh. "random" just means that the property descibed gas a stochastic variance, it doesnt say anything of the distribution of this variance. Specifically it does not imply that the distribution is such that all variants are equally probable.

[@joenathan2135]

eh. You should watch the actual video.

[@matswessling6600]

@ i did.

[@eliasednie]

I think epigenetics allows for more elastic gene expression than "make-or-break" mutations. Something something fractal genes might be more forgiving of a tweak here or there, depending on environmental pressures.

[@PasseScience]

We are back!

[@danieltomitch7048]

What a GOD TIER video, I'm in love with it!

[@kristijan8518]

This argument comes down to how you define random. Some physicists claim that random doesn't exist, just lack of information.

[@Paulus_Brent]

Random means that the process is so complicated that we will never be able to follow the chain of causes and effects, and that we must describe it in terms of statistical probability functions. It doesn't mean anything more than that.

[@FilterYT]

You are awesome! Thanks

[@judewarner1536]

The breaking strength of a uniform wire, fibre or tape is proportional to its length, as well as it's fundamental tensile strength. The computer tape, in the example, has the predicted breaking position, based intuitively on the highest concentration of holes, further away from the right, and the stretching force is biased by the dominant hand. The breaking point is, thereby, shifted away from the dominant side and towards the shorter distance from the "fixed point", the left hand. Had the weak spot been centrally placed the tape would likely have split exactly on one of the two sets of maximum perforation. Nevertheless, a good physical allegory.

[@rhayat10]

We could ask: Are the mutation hot spots/cold spots distributed randomly? That is to say, could there be selective pressure to keep certain regions relatively mutation-free, while encouraging mutations in other regions?

[@TonyTigerTonyTiger]

Good. But not once did he say the phrase that has been around for decades: saying mutations are random means they are "random with respect to fitness".

[@lorenzreiher1407]

If i heard "mutations aren't random" i would assume that to mean that it's more likely for say a beetle to mutate red skin rather than blue skin, or for something in its eyes to mutate than in the legs. It seems that the color one is sort of true, given that there are more cases of albinism than xanthism. But i mean in cases where the expression is encoded in the same way of the gene, so it would take the same "route" and effort to express red skin as it would blue skin, but obviously most animals would need quite a different and much more complex and therefore unlikely series of mutations to produce blue pigments than to produce white or yellow pigments.

[@stefaniac781]

I thought that "mutations are random" meant that the environment does not "induce" those mutations, but just selects them.

[@johningham1880]

If, as I suspect, this is an optimal strategy, then I would imagine it was only a matter of time before evolution started tuning its own hyperparameters.

[@bobaldo2339]

Thanks for the informative video. The title is, I believe, a bit unfortunate, as it could be click bait for people who don't believe in evolution (or that the world is round, etc.)

[@ragg232]

You can't please everyone

[@ragg232]

@@bobaldo2339 You could explain this as being similar to flowing water. As water tends to flow downhill due to gravity, mutations tend to "flow" towards specific kinds. Hope this helps.

[@charlesmarshall7045]

Good video.

[@bjd1980]

I want a tutorial or materials list of your model!!!!

[@YarPirates-vy7iv]

How did you find out about my elephant tesseract genome project?

[@indeecjo]

As a person with no biology background. I love watching your videos.

[@infinitemonkey917]

Any thoughts on the warnings about synthetic mirror life?

[@blakeweigel6475]

Is this the same person narrating as the old evolution videos?

[@rer9287]

random simply means the is either not enough information to know the outcome or there isn't enough care to know. When someone posits an exception to this, they are committing and argument from ignorance fallacy.

[@johnkeck]

Excellent!

[@Lardzor]

Does mutation bias include 'non-viable' mutations? I assume many mutations will result in a fertilized egg that dies early in it's developmental process. These mutations occurred, but are not likely to be observed in any study.

[@StatedClearly]

Mutation bias doesn't stop non-viable mutations from happening. Mutation bias isn't a good or bad thing, it's just a thing. That said, some researchers are claiming (and this is still being debated) that natural selection can exploit biases. They say selection favors the protection of essential genes over non-essential regions of DNA, which reduces birth defects: kzbin.info/www/bejne/b4C9ZH2BqbSIZ80 These studies are done on sperm, eggs, pollen, and seeds instead of offspring. This lets them catch fatal mutations in their data before natural selection can purge them. Some purging still happens, though, in the early stages of gamete production.

[@Lardzor]

@@StatedClearly Interesting. That implies that natural selection has insulated mission critical portions of DNA from excessive mutation, either by burying them inside the DNA ball, or by using sequences more resilient to breaking. It makes sense that this research would use gametes so that non-viable mutations would be included. Thanks for the response.

[@styleisaweapon]

Just started watching. In the world of artificial evolution, crossover is the most important factor. A system with only mutation isnt any better than hill climbing.

[@trjberg]

At 4:00 - I have seen people working with such things. (Sweden.)

[@Dilimdal]

Only pure random thing in our known universe is quantum, for now

[@Siskovski]

Tesseract in the DNA?! That would be something Zeus would have had

[@rohithpokala]

Babe wakeup. Finally, stated clearly uploaded his new video.

[@totalfreedom45]

The three greatest scientific theories so far, passing *_all experimental tests_* with flying colors, are evolution, special/general relativity, and quantum mechanics; we venture beyond them at our own peril. 💕☮🌎🌌

[@marverickbin]

Oh, I want a dna toy now

[@spliter88]

did you do something with your voice here It almost sounds sped up because your voice is higher and a bit synthetic sounding

[@GabrieleCannata]

Those dice are wrong...

[@puncheex2]

If you think that paper tape was used only in the Soviet Union to store programs and data, I'm here to tell you that you are wrong. Good old American paper tape had exactly the same problems. Well, until American plastic tape came along. Poor old 0x7f always got the bends. You've never programmed until you used an American Flexowriter with a CDC 910.

[@JohnSmith-ik8nt]

Called it

[@ChadToney]

I’ve heard teeth can evolve faster than other physical attributes. Is this an example of what you’re talking about?

[@koppite9600]

What are teeth in the first place?😂

[@StatedClearly]

I've not heard of a hotspot in teeth genes, but selection is super strong for teeth in mammals, since they're so essential in survival. We'd expect teeth to change with selection pressures pretty fast.

[@ayybe7894]

@@StatedClearly a fun example of that is Wisdom Teeth in humans. We've changed culturally MUCH faster than evolution typically works, so we don't NEED wisdom teeth anymore. Our bodies don't know that yet, and we don't really select for "non-impacting wisdom teeth" reproductively lol

[@koppite9600]

@@StatedClearly That tooth is part of how it was created.

[@FlandiddlyandersFRS]

​@@koppite9600 Prove it.

[@GottfriedLeibnizYT]

It's such a breeze of air to watch something scientifically accurate away from all the toxic and misguided creationist contents.

[@Pottyde]

Si they aren't random. Got it. 👍

[@osobaum]

Quality

[@bestuan]

some parts of the genome are more/less likely to mutate? underwhelming

[@feynstein1004]

All mutations are random but some mutations are more random than others

[@AbyssalManta]

I laughed

[@ayybe7894]

@@AbyssalManta I mutated

[@Snewbew]

As a brazilian Portuguese speaker, the translation isnt very good it feels very unnatural in the way it speaks also does have that AI generated inflection that feels really weird on the ears

[@Snewbew]

This comment was supposed to go on the short, for some reason it got sent to the video

[@StatedClearly]

@@Snewbewthanks for the feedback. I guess it has a way to go, but better than nothing for now

[@mdesm2005]

thumbs up

[@meeklynobody3230]

Not conscious of the mutation

[@DreadEnder]

1:10 yay Bath Uni! I honestly had no idea Bath university owned the Milner centre for evolution. That’s awesome since it’s my backup university of choice Not to be confused with the Milner centre of creation, a private evangelical institution in the United States dedicated to spreading misinformation about science and medicine and promoting conservative Christian beliefs.

[@FlandiddlyandersFRS]

That's some transatlantic irony right there.

[@DreadEnder]

@ you don’t know the half of it!

[@florentinobajo]

+1