Introns

In the 1970s, when scientists compared the sequences of DNA in genes with the sequences of RNA encoded by those genes, they made a puzzling discovery: the DNA of most genes in animals, plants, and other eukaryotes contains too much information. The extra segments of largely useless information were named introns, and they must be cut out of RNA before the protein is made. Exons are the portions of the gene that remain in the RNA after the introns have been removed.

  • Relics of Eden

At every turn evolutionists are faced with inventing yet another story. But that’s ok because, to paraphrase dazz, they are used to it by now.

At some point in some lineage in the history of life it must have been advantageous to insert crap into the genome. But that’s simply not allowed, under the central dogma. Even so, some mechanism must have evolved to make it possible to insert crap into the genome, and then yet another mechanism evolved to remove the crap from the DNA so that protein could still be produced from genes in spite of the fact that genes had become filled with junk.

At some point, the evolutionary story stretches credulity.

Assume a gene without an intron. Now imagine a scenario in which some piece of crap of indeterminate length gets inserted into that DNA sequence. Imagine more than one. Imagine that protein manufacture continues unabated in spite of the insertion. Imagine now an imaginative mechanism arises to excise the crap out of the gene. Let your imagination run wild!

It’s simply difficult for me to believe that “it just happened, that’s all” is rational. It throws rationality, and science, out the window.

What is the most recent and the most plausible explanation for the rise and fall of introns?

302 thoughts on “Introns

  1. The purpose of your posts, though, seems more to dazzle than to inform.

    They inform the ID side. I know most IDists are probably not being fed this stuff from anyone except me. How do I know this? Do you see any other IDists argue against junkDNA the way I do? Nope.

    I also know for a fact that I probably have more specialty in this area than the average Joe IDist because IDists have recruited me to do fact finding missions like I’m doing at the NIH every almost every week during the fall and spring.

    I’m merely sharing some of my findings.

    These aren’t ‘new perspectives’. It’s just Google-copy-paste. I (and anyone else), am perfectly capable of going out and reading the literature

    Someone as bright as you could do all the look up like you said. But I’m trying to help out perhaps some of the mentally challenged in our community like (er….er) — I better not name names.

  2. Mung,

    Lazy denialism at its worst. I honestly don’t know what motivates people to go on the internet daily just to say variations – and not many variations, at that – on “Nah. Don’t buy it”.

    OK, you don’t buy it. Nothing will persuade you to buy it. Got it. Got it bloody years ago.

    Try this. It won’t be what you seek, but to dismiss such painstaking work as ‘creation myth’ is a little unjust, I feel.

  3. stcordova,

    Do you see any other IDists argue against junkDNA the way I do? Nope.

    Yes! Every last one of them! The ID community is convinced to its boots that junk is a ‘myth’. You are preaching to the choir, who snap at your offerings like sealions at sardines. “Look! It’s complex!”. “Yes! Yes, it is! Tell us more!” It’s like shooting fish in a barrel.

  4. Larry, to Mung:

    It’s never a good idea to assume you can challenge evolution just because of personal ignorance.

    Mung — a lifelong resident of Dunning-Kruger Street — didn’t get to be the most prolific commenter at TSZ by letting his personal ignorance stand in the way.

  5. stcordova: They inform the ID side.

    They please the ID side.

    Your nonsense doesn’t inform anybody, but the ID side simply doesn’t care, they want “must be a Designer after all” gee-whiz stories, just like you do.

    Explanation and understanding are the opposite, the enemy, even.

    Glen Davidson

  6. stcordova: They inform the ID side.

    Why only one side? How is “information” supposed to not be informative to some?
    The answer is that IDiots are much more likely to buy that fallacious crap that you call information. You’ve been told countless times that nobody claims that ALL introns are non-functional. Do you tell that to your readers? no, you don’t: misinformation. You’ve also been told just as many times why non-function is considered the null hypothesis, and you keep ignoring the positive arguments and evidence available to support it. Do you tell that to your readers? no, you don’t: Liar Liar, Pants on FIre

  7. stcordova: Prior to Darwin’s time, extravagances in biology were seen as something that was put there in order to make observers wonder at the genius of the Rube Goldberg Machine Maker in the sky.!

    What kind of insecure asshole designer does wacko complicated designs just so you can wonder at his genius? Your god is such a dweeb.

  8. keiths: Mung — a lifelong resident of Dunning-Kruger Street — didn’t get to be the most prolific commenter at TSZ by letting his personal ignorance stand in the way.

    My quest for knowledge* is insatiable!

  9. Dazz:

    You are preaching to the choir, who snap at your offerings like sealions at sardines. “Look! It’s complex!”. “Yes! Yes, it is! Tell us more!”

    At least the choir at TSZ is getting bigger than the one at UD. 🙂

  10. John Harshman: What kind of insecure asshole designer does wacko complicated designs just so you can wonder at his genius? Your god is such a dweeb.

    Reminds me of Torley’s argument that God created the natural laws so that they look fine tuned (only one set of laws and constants works, the rest can’t produce anything) so that we could notice it had to be Him. Too bad he also created logic so that we can notice that would obliterate the fine tuning argument.

    Dweeb, dweeb goddy

  11. dazz: Reminds me of Torley’s argument that God created the natural laws so that they look fine tuned (only one set of laws and constants works, the rest can’t produce anything).

    And God created life because fine-tuning isn’t adequate to provide for abiogenesis.

    So, since God didn’t fine-tune the universe to make abiogenesis happen, life’s appearance is due to a miracle. Praise Jesus.

    Somehow the contrary claims just don’t bother them.

    Glen Davidson

  12. GlenDavidson: So since God didn’t fine-tune the universe to make abiogenesis happen, life’s appearance is due to a miracle. Praise Jesus.

    Don’t you mean praise Baby Jesus?

  13. Allan Miller: Try this. It won’t be what you seek, but to dismiss such painstaking work as ‘creation myth’ is a little unjust, I feel.

    Interesting.

    Further, their ribozyme-based DNA integration mechanism enabled the development of group II introns into gene targeting vectors (“targetrons”), which have the unique feature of readily programmable DNA target specificity.

    Talk about dumb luck!

  14. Mung: I don’t think the origin of introns is impossible, I just find it miraculous. I mean, what are the odds?

    So you pick some outcome of evolution, billions of years down the line, and ask “what are the odds”?

    Well, what are the odds Mung, and why is that miraculous?

    Let’s take a look at Mung. He has approximately a 3.2 billion base genome. And probably around 100 mutations in that genome. What are the odds that Mung would have the particular set of 100 mutations he has, in his 3.2 billion base genome?

    Roughly 1 in ~1.7 x 10^998

    Yet we’re all born with about 100 mutations in our 3.2 billion base genome. We’re all unbelievably unlikely.

    Let’s ask another question of a similar nature: What are the odds of the Mt Everest? Sure, plate tectonics and erosion will make mountains. But of all the ways you can arrange the atoms into something like a mountain, what specifically emerged was the Mt Everest that exists. That a miracle too? If so, then all mountains are miracles. Which basically renders the term completely meaningless, because then everything, no matter how mundane, is from some vantage point miraculous.

    Fill a large jar with your standard 6-sided dice, stand up, empty the jar on the floor, then calculate the odds they land how they do. By throwing those dice, you’ve performed a miracle.

    To make the probability of something the tell-tale sign of it being miraculous is to make the term meaningless.

  15. You’ve been told countless times that nobody claims that ALL introns are non-functional. Do you tell that to your readers? no, you don’t: misinformation.

    But someone is telling them they are at least 90% non-functional, if not more. From reading Larry’s remarks:

    dIntrons sequences account for about 30% of the genome. Most of these sequences qualify as junk

    http://sandwalk.blogspot.co.uk/2008/02/theme-genomes-junk-dna.html

    That wasn’t very specific, but in context, I would think by “most” Larry meant 90%-99%.

    But, it’s easy to imagine every gene with introns can be serviced by those introns according to the robotic arm analogy. I’m just treating you to some exciting new possibilities you might not have thought about before.

    For Larry to prove his claim: “Most of these sequences qualify as junk ” he would have to argue against every intron in every cell in every developmental context to not be functioning like those robotic arms. That’s a tall order, and just a speculation, not proven fact.

    Not that I’m saying that every intron is functional either, but the point I’m making is that Larry can’t unequivocally assert “Most of these sequences qualify as junk ” based on experiment. It’s just his faith and trust in the mutational load argument (which ironically I accept) combined with his belief there is no intelligent designer. Unlike Larry I believe in an intelligent designer, so therefore I can accept large scale functionality which Larry can’t, even though I agree with him on the mutational load argument.

    How does this has a bearing on medical science should be obvious. Someone who believes introns are mostly functional is much more inclined to take a look at introns as something medically significant. Will research grants be awarded to projects that have a 90-99% chance of coming up with nothing (if Larry is right), or will research grants be awarded if the is a 90-99% chance it might further medical insight? Of course, the viewpoint introns are 90-99% functional will gather more grants, and thus we have a better chance of learning about introns with the working hypothesis of 99% function vs. 99% junk.

    Larry’s nay saying isn’t very helpful to the progress of this sort of medical research. That’s the point I’m making.

    Personally, I think there could be lots of junk in the genome because God cursed Adam in the garden of Eden, and the human genome that was once able to be immortal, is now mortal.

    We simply don’t know the answer to how much function is in introns, but we at least know more now about how introns are and could be functional than when the infamous e-debate between Wells and. Moran-Matheson-Hunt e-debate took place in 2010.

    Let the record show, the advantage is now firmly in Wells camp, and the only thing Wells might be criticized for is understating the potential function of “spacers” when he referred to them as “inert”. Not so. Spliceosomal introns are exquisitely functional, as far as we can tell.

  16. Rumraket,

    Let’s take a look at Mung. He has approximately a 3.2 billion base genome. And probably around 100 mutations in that genome. What are the odds that Mung would have the particular set of 100 mutations he has, in his 3.2 billion base genome?

    Roughly 1 in ~1.7 x 10^998

    In the case of Mung we know the cause 🙂 We also know the cause of the 100 mutations.

    What do you think caused the proliferation of introns inside DNA? Introns that had the ability to precisely remove themselves.

  17. stcordova: For Larry to prove his claim: “Most of these sequences qualify as junk ” he would have to argue against every intron in every cell in every developmental context to not be functioning like those robotic arms. That’s a tall order, and just a speculation, not proven fact.

    Why would he need to cater to your retarded analogy based demands?
    To support his claim, all he needs is supporting evidence for his claim. How come you missed another opportunity to address the POSITIVE arguments for jDNA? (mutational load, C-value, etc..)

    Sure those don’t address particular elements (for all I know) but studies in search for function in elements considered to be mostly non-functional, find function once in a blue moon. I know that doesn’t “prove” they’re not functional, but I would say that counts as supporting evidence for non-function as the null hypothesis.

    As a layman, all I can do is try to apply some logic to the basic concepts I (think) understand. Sequences that are not conserved point to non-functionality. Some of those could have recently acquired function though. What are the implications of assuming that non conserved sequences have function? millions upon millions of base pairs acquiring function in very short time spans?

    That’s just absurd.

    Again, I’m just a software engineer with no training in biology. If I’m making basic mistakes in my reasoning I appreciate corrections

  18. colewd: We also know the cause of the 100 mutations.

    Which are often lethal, or cause horrible diseases to innocent children. Miracle! Praise the lawd!

  19. How come you missed another opportunity to address the POSITIVE arguments for jDNA? (mutational load, C-value, etc..)

    Mutational load is accepted by creationists, it’s good evidence we didn’t evolve. The load argument cuts both ways.

    The C-value paradox is an argument from ignorance, not a positive argument.

    In contrast, I argued from the facts. But since Allan is sick of me listing the facts, perhaps I’ll spare him and you.

    On the other hand, since I have a small fan club of 3 people here at TSZ, maybe I might treat them to some more facts. 🙂

  20. stcordova: How does this has a bearing on medical science should be obvious. Someone who believes introns are mostly functional is much more inclined to take a look at introns as something medically significant

    Yet all the papers you cite are authored by evilutionists! while you and the DI and the entire IDiot community put exactly ZERO dollars into lab research to find function. Can you be any more of a hypocrite?

  21. stcordova: Mutational load is accepted by creationists, it’s good evidence we didn’t evolve. The load argument cuts both ways.

    Sal in a nut shell. You accept mutational load, for some wacky reason you think it supports creationism. Weren’t we talking about jDNA though? It’s impossible to have a rational debate with you or your ilk

  22. stcordova: But, it’s easy to imagine every gene with introns can be serviced by those introns according to the robotic arm analogy.

    It’s easy to imagine all sorts of things.

  23. Larry Moran: It’s never a good idea to assume you can challenge evolution just because of personal ignorance.

    But it’s OK to accept evolutionism based on your personal ignorance. Got it.

  24. stcordova: The C-value paradox is an argument from ignorance

    Really? You just love to whine about the 80MB human DNA. How much storage does the onion DNA take? Do you dispute that the DNA of onions is mostly junk?

  25. Rumraket: dazz: But, it’s easy to imagine every gene with introns can be serviced by those introns according to the robotic arm analogy.

    It’s easy to imagine all sorts of things.

    That quote is not mine, it’s Sal’s (just clarifying)

  26. stcordova: The C-value paradox is an argument from ignorance, not a positive argument.

    No, the c-value paradox is a question, to which there is a simple answer: Genome-sizes vary so much, even between relatively closely related species, because it’s mostly junk accumulating due to stochastic variations in the activity of selfish genetic elements, most of which have no effect on organismal function.

    In other words, the junk-hypothesis has the greatest explanatory power while simultaneously being the simplest explanation.

    Why do one species of Onion need 5 times as much non-coding DNA as another, very similar one? Why do Norway Spruce need a 20 Gbase genome? Why do some amoebe need several hundred Gbase genomes?
    Why do one species of water-flea, virtually identical to another species of water-flea, need ten times as much non-coding DNA?

    We have an extremely simple explanation that explains it: They don’t.

    The simplest answer is that they don’t all that extra non-coding DNA. What we’re seeing is stochastic variations in the activity of selfish genetic elements, in different lineages, over geological time.

    Selfish genetic elements known to be selfish, which copy and insert themselves in other places in the genome. The whole thing makes perfect sense at every level. They look like selfish genetic elements, they act like selfish genetic elements. They look like they degrade due to deleterious mutations over time, so some of them look much older and more degraded than others. Some have very recently inserted, others did so tens of millions of years ago, meaning they’re the product of still-active ones that have not yet melted down to random mutations. They’re the sort of elements that would produce the pattern in genome-sizes that we see.

    In contrast, all-function advocates must invent some ad-hoc hypothesis for EVERY species on the planet and then mindlessly handwave in the direction of the future for discovering just what particular function they all must have, and why one species basically identical to another, must need 10 times the amount to achieve.. well apparently something with no detectable effect.

  27. stcordova: Personally, I think there could be lots of junk in the genome because God cursed Adam in the garden of Eden, and the human genome that was once able to be immortal, is now mortal.

    Actually, Sal, it was the ground that was cursed. No wonder YECs are so confused.

  28. dazz: That quote is not mine, it’s Sal’s (just clarifying)

    Yeah I thought I responded to him, don’t know why it got attributed to you. Corrected!

  29. colewd: In the case of Mung we know the cause We also know the cause of the 100 mutations.

    So what? It’s a complete irrelevancy whether we know the cause or not. The probability is still unfathomably low.

    So if we didn’t know the cause, are you saying that would point to something else? Isn’t that a textbook argument from ignorance? “We don’t know the cause, but it appears unlikely – therefore God” Is that what you’re saying?

    What do you think caused the proliferation of introns inside DNA? Introns that had the ability to precisely remove themselves.

    Self-splicing introns remove themselves when they have been transcribed into mRNA form. They splice themselves out of the mRNA. They are ribozymes, pieces of RNA with catalytic activity. They don’t “remove themselves” from DNA, only from messenger RNA.

    When they are in DNA form, they do nothing. It is only when RNA-polymerase has transcribed a piece of DNA that contains introns, into pre-mRNA, that the self-splicing introns can cut themselves out. When this has happened, they now exist as a piece of RNA in the nucleus, which can be reverse-transcribed by Reverse Transcriptase back into DNA, which can subsequently be inserted elsewhere in the genome. That’s how they proliferate. They’re ribozymes, they “act” when their sequence has been copied into RNA during trancription, and once reverse-transcribed back into DNA, take advantage of cellular processes that “repair” damaged/broken DNA. But the original DNA they were copied from still contains the intron-sequence, and will for the rest of time unless they happen to degrade due to random deletion mutations. But random deletion mutations are relatively rare and rarely delete more than a few nucleotides, so over generations are a much weaker force of deletion, than introns are a force of copying and insertion.

  30. Rumraket: Yeah I thought I responded to him, don’t know why it got attributed to you. Corrected!

    No prob Mikkel…. and since you’re here, can I please ask if this makes sense?

    dazz: As a layman, all I can do is try to apply some logic to the basic concepts I (think) understand. Sequences that are not conserved point to non-functionality. Some of those could have recently acquired function though. What are the implications of assuming that non conserved sequences have function? millions upon millions of base pairs acquiring function in very short time spans?

    That’s just absurd.

  31. Rumraket: Selfish genetic elements known to be selfish, which copy and insert themselves in other places in the genome.

    The genes are selfish. The non-genes are selfish. It’s a miracle anything gets accomplished. 🙂

  32. The is supposed be The Skeptical Zone but the body of skeptics in charge of the TSZ are only skeptical about the ID… How is this fair name for this blog? Why didn’t they call it “The ID Skeptical Zone”? It would be more accurate.
    Has anyone seen one of the TSZ promoters being skeptical about their own beliefs, like evolution or OOL?
    I doubt that very much…

  33. J-Mac:
    The is supposed be The Skeptical Zone but the body of skeptics in charge of the TSZ are only skeptical about the ID… How is this fair name for this blog? Why didn’t they callit “The ID Skeptical Zone”? It would be more accurate.
    Has anyone seen one of the TSZ promoters being skeptical about their own beliefs, like evolution or OOL?
    I doubt that very much…

    Gee, and they’re not skeptical about the spherical earth either.

    Why not question well-established ideas just because some ignorant theists want you to?

    IDists are forever being relativistic. How else to cling to nonsense lacking meaningful evidence?

    Glen Davidson

  34. GlenDavidson: Why not question well-established ideas just because some ignorant theists want you to?

    LoL! No one is asking you to question well-established ideas. Evolutionism doesn’t have such a thing as well-established

  35. GlenDavidson,

    Glen,

    Since you seem to be an expert, why don’t you tell us all what scientific evidence convinced you that life originated not only by chance but also how random processes have resolved the circular process that some call irreducible processes?
    What I mean by that is how natural processes have resolved this issue for ALL the components to be present for the process to take place without any known mechanism to make them present in the process?
    Do do follow? Or should I give you many examples in question?

  36. J-Mac: The is supposed be The Skeptical Zone but the body of skeptics in charge of the TSZ are only skeptical about the ID…

    This kind of comes up occasionally, like about every month.

    If you have something in particular that we should be skeptical about, that hasn’t been brought up by Sal or Mung or Joe G, feel free to jump in.

  37. petrushka: This kind of comes up occasionally, like about every month.

    If you have something in particular that we should be skeptical about, that hasn’t been brought up by Sal or Mung or Joe G, feel free to jump in.

    That’s pretty much the problem- you don’t listen to anyone, which is strange given you still don’t know how to test the claims of blind watchmaker evolution.

  38. Sal in a nut shell. You accept mutational load, for some wacky reason you think it supports creationism.

    Well, even given Larry’s 10% figure of functionality, that implies more mutations than the Muller limit anyway. So, to quote Kondrashove, “why aren’t we dead 100 times over?” Answer: we were created not too long ago.

    So Larry’s already bending his non-functionality rule to grant 10% functionality. He could of course bend his 10% numbers some more can’t he?

    So if Larry doesn’t strictly adhere to his own mutation load arguments, why should anyone else?

    In fact, I was the first guy at UD to put the mutational arguments on the table, as far back as 11 years ago when I gave this book by a world famous genetic engineer a glowing endorsement:

    Respected Cornell geneticist rejects Darwinism in his recent book

  39. J-Mac: The is supposed be The Skeptical Zone but the body of skeptics in charge of the TSZ are only skeptical about the ID… How is this fair name for this blog? Why didn’t they call it “The ID Skeptical Zone”? It would be more accurate.
    Has anyone seen one of the TSZ promoters being skeptical about their own beliefs, like evolution or OOL?
    I doubt that very much…

    Stick around a while. You’ll find that the reality-based regulars here will disagree about the relative importance of selection vs drift, about gun-control, about libertarianism, and about altruism in social insects, sometimes quite violently…

  40. Alrighty then. Hitting the books:

    According to one school of thought, early cells – the common ancestors of procaryotes and eucaryotes – contained introns and these were lost in procaryotes during subsequent evolution. Procaryotes typically reproduce very rapidly, and the advantage of a smaller genome (allowing faster DNA replication) could have been one of the factors contributing to the gradual loss of introns in bacteria. Consistent with this idea, simple eucaryotes that reproduce rapidly (some yeasts, for example) have relatively few introns, and those introns that exist are usually much shorter than those of higher eukaryotes.

    – Essential Cell Biology

    And that’s what it has to say about the evolution of introns.

    It doesn’t say where introns came from, nor why, but takes a stab at when. Sometime before procaryotes and eucaryotes diverged from their common ancestor. Score one for skepticism.

  41. stcordova: Well, even given Larry’s 10% figure of functionality, that implies more mutations than the Muller limit anyway. So, to quote Kondrashove, “why aren’t we dead 100 times over?” Answer: we were created not too long ago.

    That isn’t a solution. If the entire genome is functional, nobody should ever be born alive. 6000 years won’t save you. Last Tuesday won’t even save you. What conclusion can be drawn from that?

    And of course the evidence that we weren’t “created not too long ago” also precludes that solution. You’re cherry-picking again.

  42. J-Mac:
    GlenDavidson,

    Glen,

    Since you seem to be an expert, why don’t you tell us all what scientific evidence convinced you that life originated not only by chance but also how random processes have resolved the circular process that some call irreducible processes?
    What I mean by that is how natural processes have resolved this issue for ALL thecomponents to be present for the process to take place without any known mechanism to make them present in the process?
    Do do follow? Or should I give you many examples in question?

    Oh no- time for the “natural selection is not random” drivel…

  43. DNA_Jock: You’ll find that the reality-based regulars here will disagree about the relative importance of selection vs drift, about gun-control, about libertarianism, and about altruism in social insects, sometimes quite violently…

    I hate to think which reality I occupy. 🙂

    I recently viewed the movie Interstellar. I guess I could identify with the Coop, pushing books out of a bookshelf on to the floor in an attempt to communicate with the “real” world where his daughter was.

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