What is Junk DNA, and Why Do We Have So Much?
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- Опубликовано: 18 сен 2018
- Have you ever wondered about junk DNA? Each person's human genome is 3.2 billion base pairs long and contains around 20,000 genes, but how much of that is garbage? Find out all you need to know about Junk DNA in this new episode of SciShow, hosted by Hank Green!
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Sources:
ghr.nlm.nih.gov/primer/basics...
www.newscientist.com/article/...
academic.oup.com/gbe/article/...
journals.plos.org/plosgenetics...
www.ncbi.nlm.nih.gov/pmc/arti...
www.nationalgeographic.com/sc...
www.nytimes.com/2015/03/08/ma...
blogs.nature.com/news/2012/09/...
www.nature.com/articles/natur...
blogs.discovermagazine.com/not...
www.genetics.org/content/186/4...
www.cell.com/molecular-cell/f...
www.frontiersin.org/articles/...
mcb.asm.org/content/32/24/4892...
biologydictionary.net/intron/
www.nature.com/scitable/topic...
www.nature.com/scitable/topic...
A "Shrek" reference is always a good call.
Albert Demello I honestly can’t think of a situation where it wouldn’t be a good call. So, I concur! (Side note: concur is an under appreciated and underused word!)
I also concur with your comment on the word, “concur.”
i'm not so shrek about this.
Tom, have you seen the movie Catch Me If You Can? There's a funny scene in that involving the use of the word concur 😛
I was only 9 years old
I loved Shrek so much...
Damn, even most of my DNA is useless.
Pixx it’s alright pixx. The rest of your DNA is vital.
@@TommoCarroll Dang u rite
it is all useless, since the rest made you. jk. i love u?
Pixx there you go buddy! See! It’s not all bad 😄
We are all useless.
Hank is freaking adorable. "I thought it was really good. I liked it!" 😂 I love it when people are proud and enthusiastic about what they do. It makes my heart happy.
Dialogue in my brain.. Hank says "They just jump around" ... my brain ... "well, there is a missed opportunity... Hank, "They just listened to House of Pain too much"... me.... "Give your writers a sweet ass Christmas bonus".
The existence of junk DNA happens in Genetic Algorithms as well. As genomes are mutated and bred, some very successful genomes (organisms) carry 'code' that isn't used or has no effect on the functional result when there are a limited set of input parameters. These typically will weed themselves out over time if the evolutionary engine places value on shorter genomes and more efficient code. But throwing around 'junk' in the evolutionary process is part of what makes it work. An organism in nature might have 'junk' that isn't functional for 'today', but might have been useful in the past and may be useful in the future. It's even possible that an organism has experienced cyclic reactivation of portions of the genome as conditions in the environment change.
So, basically, we're poorly coded and buggy... like a Bethesda game.
LOL true dat. Thank the nine for the unofficial patches.
@@alexthompson8977 Time to attempt a debunk, I'll be back in a couple minutes.
@@anotherks7297 ok I'll wait :)
@@alexthompson8977 Information seems good and Birney is well credited. I'd have to read a bit more from the actual published papers.
You pass.
@@anotherks7297 I see it as good evidence but alot of people(all from the evolutionary side) attack it savagely. Why? Because evolution needs alot of junk dna. So little to no junk dna = no evolution. Clearly you see why they have a problem?
It mainly boils down to what "functional means". You can get up to 80% of the dna if you use functional loosely. Or you can get a very small amount if you use function specificly. Another thing why people are angry is because if it is proven that most or all of our dna is useful then creationists get a big score and evolution gets a big hit.
The idea I was going with is DNA is a hoarder; for onions it's like the house full o' papers and junk; for pufferfish their DNA was decluttered and for us, we're at the drawer stage in the kitchen or room stage in the house where there's lots we might need and we've kept. Some of it is the inevitable plastic bag drawer, the old screw jars, the lego box the kids had when they were young, some of it is the copper wiring that could be used to put up the fairy lights in the patio we just have not got round to, or the sound system that's to go with them. I'm really impressed with all the coding analogies; you guys just rock.
5:31
Even if they are very tasty, and have all those layers. *_Like ogres._*
Electroflame 618 yeah, can someone please explain this for me?
Shrek. God I'm getting old
@LowellMorgan Shrek 1, to be more precise
Hank eats ogres. Jesus Christ, the man is a savage.
someBODY once told me
As a genetic epidemiologist (and biologist) I thank you for making this information approachable to the general pubic. As time goes on we actually find more and more function for DNA sequences we previously called 'junk'. How much is actually functional may never be known though. Humans are complicated.
"How Much Junk Is in Your DNA Trunk?"
I'm 100% trash, fam.
Speak for yourself. 🤔🤔🤔
During my genetics degree I did an essay called " non coding DNA junk or func" 😂
How did you get a degree in genetics when you can't even string a sentence together?
Answer: your Stupidity gets USED against other humans.
Trendywendy10 haha! Please tell me you got additional marks for your title? My dissertations (2!) titles were suuuuuuper boring, especially compared to yours!
More papers need to have this kind of tittles. A bit playful? Sure, by still gets the point across and man, English papers (aka most papers) have a tendency to be very stoic.
@@catmagic2226 My optimistic nihilism says "they shouldn't care".
Raven, posting a comment on RUclips is less formal than a dissertation. A few minor mistakes aren't the end of the world.
Why did you capitalize "Stupidity" if it isn't a proper noun? That's a minor mistake, so you're both not 100% perfect.
Great video! For me, this was the sweet spot in terms of depth and technical details. I hope the Complexely Team makes more videos like this!
This sort of presentation is _exactly_ why I love SciShow. A lot of work went into this presentation and it shows. I am constantly proud to support this channel and Complexly in general.
Holy damn, there was so much informations in the episode. I'll need to watch this one multiple times to even start understanding some of it. Great video!
As a molecular biologist I can say I enjoyed this episode immensely! Thanks!!
I love that you bring science to us in a way easily understood, but not treating us like we are dumb! Keep up the good work!
"They jump around, because they listen to House of Pain too much." Classic.
My deoxyribonucleic acid brings all the boys to the yard...
HK hahaha this was a thing of beauty. Brought a happy tear to my eye
🎼And they're like, it codes more than yours, and they're like it codes more than yours, I could split you but I'd have to code
I get the reference, but I don't get why you made the reference.
@@maracachucho8701 so u dont get it then?
Maracachucho the “milkshake” in the song isnt a literal one it actually refers to the *Ahem* -junk in her trunk
Wait, my DNA is like the trunk of my car? There's a dead body in my DNA?
Well, eventually...
Oof
FBI OPEN UP
I know you joke (or do you?), but it's pretty common to have an expansive slew of dead genetic info stripped from the corpses of viruses that once attacked your body and planted into the sequence as a reference tool for future use. Basically, that section of your DNA is an encyclopedia your immune system and such can refer to whenever it meets a new viral infection and plan its attack accordingly.
It's like with that one assassin bug that carries around the heads of its slain prey as an armor. Nature is scary.
Silly bugger, you're not gonna get far without a shovel =P
That was amazing! You guys always do such good work!
Some "junk" genes can also produce small, noncoding RNAs that work to break down mRNAs as a method for controlling gene expression through a process called RNA interference, which is an interesting mechanism. Speaking of which, could you do an episode about RNAi? I may be biased, since I've done some undergrad research into it, but I think it could be a very interesting topic.
Thank You and all who work on Scishow
5:33 The memers would be proud.
wow! that was amazingly good! an epic amount of tricky information presented so succinctly and clearly... microbiologist Hank, shining!
I love how Hank gets all envious over the amount of dna an onion has compared to himself. Lol
You guys are awesome. Thank you
This was very nice, I appreciate the amount of background
The “House of Pain” reference was awesome!!🤣
Legit just had a seminar about this lol love your vids!
Great episode indeed!! I thoroughly enjoyed it!! Thanks!!👍🏻👍🏻😃
I love this channel so much :)
might be one of your best videos
Hank Green is hilarious, i love this fella!
I thought it was really good to see and I liked it too! Especially the Shrek reference. Great vid. Got my sub 👍
i loved this episode, the jokes were on fire : D
As a mathematical and computational biologist, I quite appreciate the honest coverage of this video (and the courage required to not shy away from the complexity of it all).
Great video!
A concept I picked up from "The Extended Phenotype" by Richard Dawkins, was the evolvibility of a species can be a trait that natural selection can work on. So all that junk DNA can lend variable traits to a species by copy/paste mistakes in the DNA. The more mistakes that junk DNA makes, the more variation in the species, the more apt a species is to evolve, therefore giving that species a leg-up in adaptability.
I like this cutting edge stuff.
I wonder if a use may be found for the non-"functional" DNA. Hard to believe a system would long support that much excess. And might it not be some kind of insulation, superstructure, energy supply? As Hank points out, it's still early; there's much yet to be decoded, many more processes yet to be understood.
That onion bit made me laugh. "It shouldn't take 5 times as much DNA to be an onion"
Thank you so much for this information...
I'm sure tons of people would be disappointed without a definitive answer, but I care more about my personal growth in understanding the evidence.
I love how he said it was a good episoode and he really liked it lol!
OMG I forgot I had this in my watch list, I learned about this is my Biology class 2 weeks ago LOL
I wonder when or how many times certain plants and animals have evolved, when certain things branched off from each other, and how slowly or quickly they did it, and if that effects the amount of junk DNA they have, if at all. I'd love to hear an answer to those questions and if there's any correlation between the two.
"...variants of protein from a single gene."
Sounds like something from computer architecture for some reason.
I might have to watch this one a hundred times to get it all digested.
So much discussion over pairs of pants. Amazing.
I'm not sure if there are new writers or if Hank is just making more jokes, but I've noticed more levity in some recent episodes, and I like it!!
Great video. Tarts also have layers!
I remember hearing a thing in regards to certain plants having more genes than us: "can you survive having huge chunks of you removed and just grow them back? Can you live in the harsh elements with no protection? Can you last months without food or water? Etc."
Like with an onion.... You can take the onion plant out of the ground, cut off all the shoots/leaves and roots so it's just the bulb, then store it in a cupboard or fridge for months (so no food or water for the onion)... And it'll still grow. Sometimes on its own, but otherwise just by sticking it in some soil.
Humans can't lose most of our body and then be deprived of food and water for months and still remain alive. So like. I think it makes sense? Onions are more incredible than people give em credit for.
I am so mesmerized by Hank’s ears.
"I thought it was really good, I liked it."
100% Right with ya there.
Curious, could some stretches of DNA be one time use? Could some DNA be used for some structural reason?
My class just finished our functional genomics discussion on ENCODE and Graur's sassy pushback paper. Lol this video would have been a great review for our exam.
Excellent summary of a very complicated and controversial subject.
Genes thumping to House of Pain, I see what you did there Hank!
Sh*t doesn't matter yo.I like 100 % of my DNA.
best title ever
If a piece of gen doesn't make proteins or stick to anything but the space it occupies still need for other things to happen that means it's not junk.
I'm craving a Pop-tart right now. That must must be my junk food DNA kicking in...
as a staff in a molecular biology lab, watching this is like hearing one of my colleagues explaining our work XD
From where I am from -as far as I know- back then (some 50 years) those industrial birth rates of ~15 kids, required for a population to be able to maintain some 80% of its genome functionally active, were not that rare to find.
My core family is small in number, particularly. However, many of my closest relatives are almost right there, near the mentioned rate. In one family, there are 11 cousins. Others have around 8 or 7 kids. Moreover, my father equally grew up in a house of 10 brothers and sisters.
Knowing of many other families that, back there, were big numbered, too, I wonder how far back this tendency goes on. Also, how this could affect, if at all, the genetic relationship inside the society I live on? Any idea, anyone?
The mechanism of DNA is very sophisticated. The non coding regions might have a role in controling the molecular machines that work on DNA itself. There might even contain a second code that decide which gene should be avtivated.
Or maybe it’s INACTIVATED DNA.
Robyn I think that still falls under useless.
Robyn - Good insight.
An excellent RUclips account nah. Still means it could be activated and also my have been activated in the past.
Robyn - Good point.
Might be handing having partly coded dna ready to be made into something useful, in case we need it. Could be part of the development process of new useful stuff. Partly completed job that didnt go anywhere at the time, but may be ready to go quickly when conditions change...
Time to clear my cache
Some of those junk DNA need the bite of a radioactive spider to activate.
lets just make a bunch of clones with a control and some with "junk" removed and see if they work.
Just make clones LOL 4Head its so easy 4Head
...
“It just doesn’t do anything “ aka “we just don’t know what it does yet.” but more arrogantly.
You are a seriously good presenter.
The eighties references are strong in this one!
8:30 describes my grandparents pretty closely: they had 12 children. All of them survived to adulthood and lived to their 90’s and 3 of them lived past 100. My Aunt passed away at 107 years old and she was sharp & spry right to the end. (Same with all my aunts & uncles)
Their parents, my grandpa & grandma, were born at the end of the 1800’s. They lived to 97 and 94, respectively.
I’m the daughter of their youngest child (my dad) He was born when my g’ma was in her late 40’s and my g’pa was in his early 50’s. Even crazier, I’m the youngest kid in my family... I wasn’t born until my dad was 46 & my mom was 44...
One of my best friends is a molecular biologist studying the proteins within mitochondria. She recently discovered some new ways to cause cancer.
This kind of explains why I can create sound with my ears?
Thank you for the Shrek reference, Hank.
Hank flips us off @ 6:30
Most of what I got from this is we have a lot of R/W space and onions have way more than we do.
the ogre line killed me!
Have an extra special thumbs up for that House of Pain reference! :)
What about the part of genes that controls how cells grow and connect togeher to form the human body?
I think one thing you left out is that some of the "junk DNA" may be structural. The base pairs are slightly different and some repeated sequences could affect the folding of the DNA chains which in turn affects other factors like stability and gene expression.
Cant help but think of Kevin Costner's Waterworld and how my dad has webbed toes 😂😂
Nothing more frustrating than pyrosequencing what you're sure is an oncogene only to find out it was in a noncoding region. Thank gourd for adaptive Informatics and next-gen
Came for the because. Stayed for the House of Pain ref.
Junk~ DNA
My Friends : "YES"
Please make more bee-related videos thanks I love you
I remember thinking as a student that junk DNA could simply serve as a statistical target for random mutations. If most of your genome was functional, then a random mutation would be more likely to change an important gene, likely leading to problems. However, like a game of battleship, if most of your genome is junk, then it is less likely that a valuable gene will be hit by a random mutation.
For that to be the case, there would need to be some mechanism that increases mutation rate in a larger genome (which may well be the case). Otherwise it would be like expecting your car to be less likely to break down when you park it in a car park with loads of other cars in it.
No matter how much DNA you have, the mutation rate of your genes will stay exactly the same. Not to mention that the prime way of developing new traits, is not random mutation, but gene duplication and modification, for which some junk DNA to be embedded in indeed helps.
LeonMustapha
whenever i park my car in a park car together with lots of other cars over night I expect some little matchbox cars to arise.
Hank looking scruffy today!
Lets just say enough for a whole lot of spunk
Part of that almost sounds like pre-roll on a video tape. Helps set the timecode & iron out any tracking which is incredibly important, but basically useless in regards the actual program itself.
whats tracking on a video tape, and how does junk dna track human dna?
I'm gonna change phone, that moment, you won't have any way of stalking me anymore.
And I won't lend my phone to anyone anymore, thanks for helping me with my trust issues dickhead.
Wow. I barely learned today about how DNA codes for proteins with mRNA and all that stuff. Now I can actually understand lol
Hi guys. Nice video.
Just a feedback. I had problems with the subtitles. It is appearing something like a “ghost subtitle” behind the captions. I don’t know if it’s a RUclips or my iPad problem.
Thank you.
I would suggest looking at evolutionary development and genetic switches. I would postulate that much of the "junk" is utilized in various switches. We may have sequenced the entire human genome, but we really don't know every single switch in our genome or what they are specific for. Many switches are only used during embryonic development and once their function is done, they turn off.
According to current data there are some families/subfamilies of transposons that are still moving in the human genome (Alu) not to mention that transposons play a huge role in gene evolution and speciation
"That doesn't mean anything is happening there aside from stickiness"
why is there a segment of a scishow about the sock under my bed
I love how it is near universal that ogres have layers now ❤
We need these non-coding, intergenic regions for chromatin structure etc.. Google for example "TAD"s (Topologically associating domain) which forms higher order structures of our DNA/chromatin and thereby controls its activity, stability, accessibility and more. Then we have regions close to the centromers ("center" of the chromosome) and the "ends" of the chromosomes (telomers) which act as some kind of spacer/shield.
Jump around, Jump Jump, Jump Around \o/
Thanks for the Shrek reference!