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Science Idle

Scientists Make Fish Grow "Hands" In Experiment Revealing How Fins Became Limbs 110

An anonymous reader writes "While fossils have long shown that limbs evolved from fins, scientists have shown live in the laboratory how the transition may have happened. Researchers said that the new study published in the journal Developmental Cell offers evidence revealing that the development of hands and feet occurred through the acquisition of new DNA elements capable of activating specific genes."
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Scientists Make Fish Grow "Hands" In Experiment Revealing How Fins Became Limbs

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  • by Genda ( 560240 ) <marietNO@SPAMgot.net> on Monday December 17, 2012 @04:15PM (#42316971) Journal

    New fish applaud scientist for hands...

    • by Tablizer ( 95088 )

      New fish applaud scientist for hands

      Since they are only a 10th done, they got The Finger instead.

    • by dywolf ( 2673597 )

      New syfy movie...Lionfish

      A researcher working with Zebrafish gave them hands.
      He expanded his research to Lionfish...
      Now he's awakened an insatiable hunger...

      And they're no longer stuck in the fishbowl!

  • by Genda ( 560240 ) <marietNO@SPAMgot.net> on Monday December 17, 2012 @04:17PM (#42316985) Journal

    The scientist would give them noses, they'd have something to do on those interminable waits between feedings.

  • Now the Pythons will need to change the FISH scene in "The Meaning of Life" (ala George Lucas) and have the fish in the tank shaking hands.

  • All you need to know (Score:5, Informative)

    by GODISNOWHERE ( 2741453 ) on Monday December 17, 2012 @04:22PM (#42317065)
    From TFA:

    "Of course, we haven't been able to grow hands," Casares told New Scientists

    • by gewalker ( 57809 ) <Gary.Walker@Astr a D i g i tal.com> on Monday December 17, 2012 @04:45PM (#42317409)

      And the fish died 4 days after being treated with the new gene. A complete success otherwise.

    • by Anonymous Coward on Monday December 17, 2012 @04:47PM (#42317435)

      Slashdot: Scientists make fish grow hands!

      Scientists: No we didn't...

      • by Anonymous Coward on Monday December 17, 2012 @05:52PM (#42318405)

        Title of the FA:

        Scientists Make Fish Grow "Hands" in Experiment That May Reveal How Fins Became Limbs

        Next line in the FA, synopsis:

        Scientists have successfully made fish grow "hands" instead of fins in an experiment that may reveal how animals transitioned to living on land instead of only in water.

        First line of the actual article:

        Scientists have successfully made fish grow "hands" instead of fins in an experiment that may reveal how animals transitioned to living on land instead of only in water.

        and near the end of the article, the line of the OP:

        "Of course, we haven't been able to grow hands," Casares told New Scientists

        So it's not Slashdot, it's scientific journalists (or maybe just MedicalDaily, but it's so convenient to say just "Scientists" or "Scientific journalists" to make you think that scientists form an hivemind) who take everyone for bloody idiots. Really pitiful...

        • by lxs ( 131946 )

          More specifically, it's New Scientist which has a proud tradition of behaving like a tabloid.

      • by argStyopa ( 232550 ) on Monday December 17, 2012 @09:48PM (#42320985) Journal

        To be fair, the article ITSELF is pretty confused.

        1st sentence:
        "Scientists have successfully made fish grow "hands" instead of fins in an experiment that may reveal how animals transitioned to living on land instead of only in water."

        Near the end:
        ""Of course, we haven't been able to grow hands," Casares told New Scientists..."

        So I'd submit that the summary being a little confusing isn't really the summarizer's fault this time.

      • Reading "comprehension" fail.
    • by jlv ( 5619 )

      Mod this up.

    • by slew ( 2918 ) on Monday December 17, 2012 @06:07PM (#42318617)

      But apparently they grew "hands" (which is apparently what pseudo-journalists call autopods) not hands (sans quotes)...

      However, from the truth is stranger than fiction department, a possible reason that it didn't really work might be the lack of a mediating factors like Sonic Hedgehog [nytimes.com] expression signalling (yes, that's the name of a real gene, which was named after the video game character by the Harvard researchers who discovered it) which has to something to do with making limbs [harvard.edu] from autopods, but is mostly used in the formation of scale structures in zebrafish.

  • by Genda ( 560240 ) <marietNO@SPAMgot.net> on Monday December 17, 2012 @04:23PM (#42317071) Journal

    Masturbation will still be dicey, but the kissing gouramis are now hugging and kissing gouramis. My work is done!/p?

  • God made these scientists with his own two fins so that we would recognize the potential of our water-breathing brothers. Fish have always been seen as low forms of life but now it's time to balance the scales.

    Yay, god!!!

  • Bizarre (Score:1, Insightful)

    by cfulmer ( 3166 )

    So, the hand genes were just sitting around, waiting to be 'activated' by specific DNA?

    I think that means that either Intelligent Design is real or we don't have really good terminology to describe what actually happened.

    • Re:Bizarre (Score:5, Insightful)

      by viperidaenz ( 2515578 ) on Monday December 17, 2012 @04:50PM (#42317497)

      ....or you don't have a good understand of what happened.

    • Re:Bizarre (Score:5, Informative)

      by LateArthurDent ( 1403947 ) on Monday December 17, 2012 @04:59PM (#42317649)

      So, the hand genes were just sitting around, waiting to be 'activated' by specific DNA?

      I think that means that either Intelligent Design is real or we don't have really good terminology to describe what actually happened.

      According to the article, the fish embryos continued to grow for 4 days, developing autopods, a precursor to hands. Then they died.

      Hilariously enough, this article which is headlined "Scientists Make Fish Grow 'Hands'", contains a quote from one of the scientists involved, "Of course, we haven't been able to grow hands." Basically, this isn't intelligent design, it's exactly how evolution is described to work: You have existing code for fins, a slight modification of which appears to cause differentiation into autopods. This particular change is only one piece of the puzzle, so it wasn't a viable modification.

      • by jonadab ( 583620 )
        > Basically, this isn't intelligent design

        Of course not. That would imply that the scientists who designed the genetic modification did so intelligently -- a preposterous notion. Since their custom GM fish all died as embryos, it's obvious that this was in fact a very unintelligent design.
        • Of course it's not intelligent design, fish don't need hands. Intelligent design would give them something useful to a fish, like an outboard motor, .
          • Thank you sir. And since fish do not have outboard motors we have now proven that there is no god. Unless someone wants to contend that outboard motor designers simply have a better understanding of fluids than god?

    • Re:Bizarre (Score:5, Insightful)

      by Chris Burke ( 6130 ) on Monday December 17, 2012 @05:03PM (#42317721) Homepage

      So, the hand genes were just sitting around, waiting to be 'activated' by specific DNA?

      Kinda maybe but not really? There's no gene for hands. There are genes involved in growing those tissues which comprise limbs, which are in turn controlled by other genes. Control those genes one way, you get fins, another way, you get "hands". The controlled genes were already present in the fish, and being used to make fins. Add a new mouse gene that controls those other genes a different way and you get something more like a hand.

      As a ridiculously coarse analogy, it's like saying the standard C library has the code for a chess game because if you take a tic-tac-toe game and then re-arrange a bunch of the code that controls how the stdlib functions are called you get chess instead. Yes there are important pieces being re-used but there's more to it than that.

      There's no problem with the terminology, and absolutely no need to resort to ID to explain this. Our bodies re-use the chemical machinery of life forms from billions of years ago. Just in different ways. Evolving new mechanisms for controlling that machinery is still evolution.

      • by jbengt ( 874751 )

        As a ridiculously coarse analogy, it's like saying the standard C library has the code for a chess game because if you take a tic-tac-toe game and then re-arrange a bunch of the code that controls how the stdlib functions are called you get chess instead.

        Actually more like saying the standard C library has the code for a chess game in it because if you take a tic-tac-toe game and repeat it several times, a chess game appears (and loses in four moves)

      • by cfulmer ( 3166 )

        Yeah, so I wasn't really trying to claim ID was involved (although I'm amused by how many people thought so -- see below). The point was that the idea that genes are sitting around waiting to be 'activitated' isn't really what happens. Thus, the need for a better way to explain what does actually happen.

        The structure of my argument was "A or B." If A is absurd, then "A or B" -> B, where B is "need a new way to describe this." However, a lot of people apparently thought B was absurd and concluded A,

        • Yeah, so I wasn't really trying to claim ID was involved (although I'm amused by how many people thought so -- see below).

          Yes I know, which is why I devoted the majority of my post to the fact that the terminology is fine. In your argument of "If A or B if A is absurd then B" your "B" that the new way to describe this is needed is untrue.

          The point was that the idea that genes are sitting around waiting to be 'activitated' isn't really what happens.

          Except it is. That's exactly what happened. Or at least, the description in the summary -- "the development of hands and feet occurred through the acquisition of new DNA elements capable of activating specific genes" -- is exactly what was demonstrated in this experiment.

          It's your assumptio

          • by cfulmer ( 3166 )

            Yeah. So, the summary made it sound like evolution happens when new DNA elements occur which activate individual genes, as if you could take a fish cell, feed it the right programming and out would pop a walrus or an eagle. That entire model, though, is wrong -- DNA is not a program being fed into a machine. In many ways, it's both the program and the machine itself. Adding "new DNA elements" is actually the process of adding genes (or, more precisely, adding things which when combined with other parts

    • Re:Bizarre (Score:5, Insightful)

      by JesseMcDonald ( 536341 ) on Monday December 17, 2012 @05:17PM (#42317913) Homepage

      First, they didn't actually manage to grow hands. The closest they were able to achieve was "autopods", a precursor somewhere between hands and fins. The cause of this difference was a transplanted mouse gene which increased the production of a certain protein involved in selection and development of different kinds of tissue.

      The real lesson from this is that small changes in DNA can have large effects on physiology. A bit more of a certain protein at the right point in development and you get autopods instead of fins. A few other minor changes and you might even get something approaching real hands.

      It isn't that fish have unused DNA lying around which can be "activated" to produce hands; rather, the genetic codes for fins and hands are very similar, perhaps differing by just a couple of mutations. This similarity is evidence in favor of common descent. Why would a "designer" put in the effort to make the DNA so similar? No doubt, if our own experience as designers is anything to go by, it would be far easier to achieve ideal fins and ideal hands without that constraint. Hands and fins differentiated only by the presence of a few specific proteins is perfectly consistent, however, with inherited genetic traits and natural selection.

      • Re:Bizarre (Score:4, Interesting)

        by InterArmaEnimSil ( 2549238 ) on Monday December 17, 2012 @05:46PM (#42318319)

        the genetic codes for fins and hands are very similar, perhaps differing by just a couple of mutations

        Except for the fact that while the effect of the transplanted gene was relatively small - an increase in the quantity of a protein - there is nothing saying that the code of the mouse genes which produced the change was "just a couple of mutations." My guess is that the scientists probably imported at least several Kb of already-functional code into the fish genome to produce the marginal change in the protein production. Could be more, could be less.

        Saying that the genetics are similar because the effect is similar is akin to going, "Hey, this custom Cinnamon theme on Fedora looks a whole lot like Windows XP - it must be just a few tweaks to get from one to the other!" The underlying code might be similar, or it might not, (In the case of Fedora and Windows XP, it is not) but the presumption of code similarity from product similarity is unfounded. Likewise, the presumption that the functional mouse genes are just a simple tweak or two away from functional fish genes is nonsense. In this case, they might be, or they might not, but there is simply no way to make that judgment based on the effect the code produces.

        Why would a "designer" put in the effort to make the DNA so similar?

        Code similarity is far from a "constraint." Libraries, modularity, and code reuse are the bread-and-butter of effective and efficient programming. Why make something similar? As a designer of code, I have an answer - because if similar code works in similar cases, then you don't have to bother doing it all twice, ten, or ten thousand times, saving work and reducing the likelihood of error or corruption.

        Of course, that doesn't support Intelligent Design. However, claiming that experience designing code suggests that it would be easier to re-implement a feature from scratch for every use case rather than to re-use code is a bad idea.

        On a related note - Hey, let's make this an argument about religion on a tech news site, right where arguments about religion belong! Again....

        • Re:Bizarre (Score:5, Informative)

          by JesseMcDonald ( 536341 ) on Monday December 17, 2012 @07:44PM (#42319753) Homepage

          My guess is that the scientists probably imported at least several Kb of already-functional code into the fish genome to produce the marginal change in the protein production.

          I see your guess and raise you actual science. What they did, from the article, was take a gene the fish already possessed and multiply it. The fish already produces this protein, but with fewer copies of the gene. Increasing the number of copies, and thus the amount of protein produced, resulted in autopods.

          Saying that the genetics are similar because the effect is similar...

          I didn't say that. We already know that the genetics are similar, because we've sequenced the DNA of a number of organisms and determined that they're really very similar, even when the organisms appear quite different. Plants and animals, for example, share far more DNA than one would naively expect. What I said was that the fact that a small change in the expression of certain proteins changes the development of the fins to something much closer to hands is consistent with common descent. It shows how small changes over time could have changed fins (or fin-precursors) into hands. That this actually occurred requires other evidence, which we have from a variety of sources.

          Code similarity is far from a "constraint." Libraries, modularity, and code reuse are the bread-and-butter of effective and efficient programming.

          No argument there, but where is the modularity in DNA? Where are the boundaries between the libraries and the rest of the organism? Code reuse is possible because we carefully avoid making every piece interact with every other piece. We deliberately restrict the ability for small changes in one are to have global effects on the rest of the program, preferring to create small, self-contained modules with well-defined interfaces. DNA is just the opposite: a single huge parallel program, with patches layered on top of patches, and no organizing structure to be found anywhere. What it most resembles (for obvious reasons) is the output of a genetic algorithm, the difference being that genetic algorithms are configured with fitness functions to achieve specific goals, while natural selection has no goal apart from the survival of the genes.

          On a related note - Hey, let's make this an argument about religion on a tech news site, right where arguments about religion belong! Again....

          You're the one that brought up religion. Up till now, we were discussing common descent ("evolution") and Intelligent Design, a term invented specifically to avoid the religious connotations of Creationism. However, you're probably correct that it's more honest to classify ID as religion rather than science.

          • Code reuse is possible because we carefully avoid making every piece interact with every other piece. We deliberately restrict the ability for small changes in one are to have global effects on the rest of the program, preferring to create small, self-contained modules with well-defined interfaces. DNA is just the opposite: a single huge parallel program, with patches layered on top of patches, and no organizing structure to be found anywhere

            You can think of a DNA program like the output from an optimizing

          • I see your guess and raise you actual science. What they did, from the article, was take a gene the fish already possessed and multiply it.

            I stand corrected, provided that hoxd13 is chemically identical in the two species, and it probably is However, I would still maintain that the scientists had to import more code, per my original guess, in more subdued fashion, into the genome - if not, then a copy-paste of a function alongside a copy of itself would not increase the size of a source file.

            We already know that the genetics are similar, because we've sequenced the DNA of a number of organisms and determined that they're really very similar, even when the organisms appear quite different.

            True.

            changes the development of the fins to something much closer to hands is consistent with common descent. It shows how small changes over time could have changed fins (or fin-precursors) into hands.

            Also possible. However, if I were the scientists behind this study, I wouldn't be really publicizing it. Not that I expect fish to grow actual fun

            • by Pav ( 4298 )

              >I would still maintain that the scientists had to import more code, per my original guess, in more subdued fashion, into the genome - if not, then a copy-paste of a function alongside a copy of itself would not increase the size of a source file.

              This kind of mutation and the mechanisms involved have been understood [wikipedia.org] for 25 years or so. Multiple copies of a DNA sequence can expand a genome in this way.

        • Regarding "code reuse", a perfect creator wouldn't need to worry about abstractions and "generic" libraries: he/she/it would make each item with what it needs and only what it needs. Abstractions are largely to help save human developers time and effort under our limited abilities, not to streamline the code-base.

          Then again, "omnipotent" and "perfect" are not necessarily the same thing. Maybe "God" is a Linux admin-like being running us a simulation/emulation. He/he/it has omnipotent power from our perspect

          • by aiht ( 1017790 )

            (Don't tell him I said that, otherwise he may click on my "cancer" check-box or something.)

            A Linux admin-like being wouldn't click on no fancy-schmancy checkbox!
            More like
            echo 1 > /proc/`pidof Tablizer`/cancer

            • by Tablizer ( 95088 )

              "Only Allah would use GUIs!" There, that'll start yet another Holy War in the middle east.

              • Heretic. You know perfectly well that Allah is the guy forbidding all imagery. You think he'd use a GUI? He's the command line guy here!
          • Honestly, presuming some kind of designer - omnipotent God, sneaky genetic-engineer alien, whatever - how would we know whether that designer would or wouldn't use things like abstractions and libraries? Saying that a perfect creator wouldn't use such things (and I said nothing about a perfect creator in the first place), is presuming that we know, despite not being perfect programmers ourselves, exactly how a perfect programmer would write code. There are plenty of human programmers who are better than m

            • by Tablizer ( 95088 )

              A perfect creator doesn't need abstractions, period. They would put in only what is needed to define the creature, not all the baggage that comes with libraries and abstraction. Why would you include a math library that has a cosine function if you never use cosines?

              But it could be the Bible is partly wrong and God is imperfect.

      • by cusco ( 717999 )
        Why would a "designer" put in the effort to make the DNA so similar?

        Laziness?
    • Re: (Score:3, Insightful)

      by Anonymous Coward

      So, the hand genes were just sitting around, waiting to be 'activated' by specific DNA?

      No. But this is like a game of telephone. It starts and ends like this,

      1. Scientists try to do some experiments to see if they can manipulate genes to see which ones differentiate limbs from fins. You know, since evolution says fish => land. (also land to fins, like whales)

      2. After lots of work, scientists get a 4-day embryos that die that have different shaped fins, like autopods. So they found gene that may be a candidate.

      3. Scientists communicate to press "Of course, we haven't been able to grow hands

  • I've been waiting for you to give sharks opposable thumbs...

  • by sjames ( 1099 ) on Monday December 17, 2012 @04:55PM (#42317575) Homepage Journal

    I for one, welcome our tool using piscine overlords.

  • by Okian Warrior ( 537106 ) on Monday December 17, 2012 @05:06PM (#42317775) Homepage Journal

    Was there a thunderstorm raging outside when this experiment was conducted?

    This just seems like the kind of experiment that would be conducted with a thunderstorm raging outside.

    Just saying...

  • This just in: Fish learning to jack off.

  • ... grow a hot looking blond with a fish tail but screwed up.

  • When we used to do experiments like that at the lab we would get death threats from the religious crazies.

    The only death threat I got was in college doing research on skewing the sex ratio in horses toward females. I was surprised a few people got so wrapped around the axle by that, doesn't seem like any big deal, even in hindsight.

    Not like making fish grow hands or anything.

  • Did they have fins? Useless "hands" + no fins = dead fish.
  • Quite a jump to make a string of organic material attached to a fish and claim that it somehow is the way fish developed legs. If I pump a fish full of air and it farts, is that the explanation I can use for my flatulence; "It's evolution!"
  • ...they can play scales.
  • .....lab grown FISH FINGERS! (how did it take this long for a fish finger joke to appear?)
  • When doing stuff like this, do you have some evil scientist laugh you practice so you can do it and yell "IT'S ALIVE!"? Because if I were making fish grow hands, I'd pretty much have to do that. Hell, I did my evil scientist laugh and yelled "IT'S ALIVE!" when I got my C++ version of our perl-based satellite ephemeris code working. It's the first time I've ever heard the entire CM team shut up for like, ten seconds.

    Honestly though, how big an achievement is this, really? Fish be growing, like, 2 heads and

  • There is little that shows how the organelles, or the difference in DNA came to be.
  • by fatphil ( 181876 ) on Monday December 17, 2012 @08:43PM (#42320317) Homepage
    Scientists have long known that consumption of (sufficient quantities of) Koskenkorva can make Finns become legless.

    Although strangely, when in this state, we tend to call them "our 4-legged friends" as they tumble off the ferry. So maybe they were gaining two legs after all.
  • TFA:

    "Of course, we haven't been able to grow hands," Casares told New Scientists
    Read more at http://www.medicaldaily.com/articles/13545/20121217/scientists-make-fish-grow-hands-experiment.htm#3malsWejISVWX0hh.99 [medicaldaily.com]

  • by Areyoukiddingme ( 1289470 ) on Monday December 17, 2012 @10:09PM (#42321149)

    They're just trying to take credit for naturally evolved fish with hands found in the ocean at Fukushima.

    Next thing you know, they'll try to take credit for creating Godzilla too.

    Shameful...

  • one says to the other, "I need a hand finishing my ale here". The other says, "Well, Bud, I would fetch a scientist to help you grow arms, but I'm afraid you'd drink like a fish."

  • captain birdseye what have you done you monster
  • So this story is interesting:

    1. Scientists create mutants
    2. Mutants die
    3. Scientists are happy about their discovery.

    What about this is NEWs?

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