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Scientists Breed Big-Brained Guppies To Demonstrate Evolution's Trade-Offs 121

An anonymous reader writes "Scientists have long suspected that big brains come with an evolutionary price — but now they've published the first experimental evidence to support that suspicion, based on their efforts to breed big-brained fish. A Swedish team found it relatively easy to select and interbreed common guppies to produce bigger (or smaller) brains — as much as 9.3 percent bigger, to be precise (abstract). But the bigger-brained fish also tended to have smaller guts and produce fewer babies."
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Scientists Breed Big-Brained Guppies To Demonstrate Evolution's Trade-Offs

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  • by Anonymous Coward on Friday January 04, 2013 @05:57PM (#42480867)

    ...oh nevermind.

  • Uh (Score:4, Funny)

    by Anonymous Coward on Friday January 04, 2013 @06:00PM (#42480909)

    "But the bigger-brained fish also tended to have smaller guts and produce fewer babies"

    Of course. Smart fish stay kids free to live fun and awesome lives in the wet.

    • by bondsbw ( 888959 )

      But can your skinny, smart fish that produce few offspring create other glowing animals []?

      Thought not. Nerds 1, Brainiac fish 0.

    • Re:Uh (Score:5, Interesting)

      by TapeCutter ( 624760 ) on Friday January 04, 2013 @09:35PM (#42483933) Journal
      Maybe they're not smarter, maybe they're just interested in different things? Animals with a gut all evolved from worms, in a sense the rest of the animal is there to keep the "worm" inside them alive. A human gut has it's own nervous system that can continue to function normally even if all connections to the brain are severed. If a fish gut works the same way then maybe they are "just" moving computing resources around between gut and brain? Kinda like getting an Obama by selectively breeding Texan Governors.
      • by hkmwbz ( 531650 )

        Animals with a gut all evolved from worms, in a sense the rest of the animal is there to keep the "worm" inside them alive.

        Sounds interesting. Got some reading material I could look at for more info?

    • Ummm.... couldn't they select for big brain AND big guts?

      • There's a hard upper bound on "expensive" organs (those that require more energy to function) based on the amount of energy a creature can consume and process.

        Some creatures (like cows) spend more on having a larger and more efficient digestive tract so that they can extract more nutrition and energy from a simple diet.
        Others (bears, us) spent more on this thinking organ so that we can selectively pick out more energy-dense foods to eat and get by with a simpler digestive system.

        In any case, if you're an an

    • They aren't that smart ... They still pee in the pool....
    • by Anonymous Coward

      film is what it is, but the introduction of the film on evolution explains it brillantly

    • I think they made the guppies middle-class.
  • by cps42 ( 102752 ) on Friday January 04, 2013 @06:02PM (#42480935) Homepage
    Guppies make too many babies in my tank, any way. How do we order these?
    • You don't... but you could get a catfish or other predator to keep the population down... Some types of catfish will eat the babies when they're born without being big enough to eat the adults, for example.

      • Just put less places to hide near the surface in the tank, and the adult Guppies will eat their own babies.

  • by Tablizer ( 95088 ) on Friday January 04, 2013 @06:05PM (#42480981) Journal

    Researcher: "We didn't find anything commercially useful, but at least the fish can do my taxes for me."

    • Re:Fringe benefits (Score:4, Informative)

      by mikael ( 484 ) on Friday January 04, 2013 @06:39PM (#42481547)

      "In this paper, we describe a method of representing the US income tax declaration form in the form of a fish tank decorated with ornaments. We placed fish food at locations representing sources of income, while taxes were represented by obstacles in the form of fish tank ornaments. The statistical average time taken by the fish to feed determined the final amount of tax due."

      • The statistical average

        Phew, I thought for a moment you'd made the classic error of using the unstatistical one.

  • But for some reason, the very smartest guppies had no interest in swimming at all but would just hang around the bottom of the tank, head side down.
    • I second this, as long as the dumber breed is kept separate from the main population.

      More bacon!

      Actually, though, this experiment does not prove much of anything. The particular gene they were selecting for might be associated with another gene for small guts, for example. And poorer nutrition would almost certainly imply smaller broods.

      We know that many genes are not independent, for example. In order to prove that this trait (bigger brains) by itself was actually the CAUSE of smaller guts and sma
  • by jdastrup ( 1075795 ) on Friday January 04, 2013 @06:14PM (#42481107)
    This was demonstrated in the first 5 minutes of Idiocracy.
    • some people still claim that film is a comedy. i just find it scary.

      • A very accurate prediction of the future masquerading as a comedy (that did terrible in the theaters but I loved the first time I saw).

        • by SeaFox ( 739806 )

          Of course it did terrible in theaters. Consider how stupid you'd have to be to pay current ticket prices and what this movie was about.

  • A Swedish team found it relatively easy to select and interbreed

    A rotund researcher licked his lips as he continued, "... a delicious side effect that we noticed was that the larger brained fish had an overall higher fat content and therefore made lutefisk that hardly tasted like soap! On a side note, we will have to breed many thousand more fish to make sure that we have not stumbled upon a localized minimum for reproductive abilities. My colleagues would agree with me if they weren't so busy utilizing the restrooms."

  • If I were to have published this paper I wouldn't have used the term "artificial evolution". I would have called it "Intelligently Designed Evolution" just to make everyone rage. Especially since they were selecting for bigger brains.

    • by PRMan ( 959735 )
      I assure you that the Creationists I know would not rage at the term Intelligently Designed Evolution. But if the term "Intelligent Design" was in the paper anywhere for any reason, it wouldn't have made it past the journal's spam filter upon submission.
    • The way to troll other scientists is not to act like a nut job. If you do that they'll simply dismiss you as a nut job, ignore you and happily go on with their much more interesting work.

      The way to troll scientists is to prove their pet theory wrong (and no, you won't do that with evolution). I'm talking about some pet theory in a sub-sub-sub-field. Unfortunately, that involves doing groundbreaking science which is rather difficult.

      Good luck.

  • Think of the guppies!

  • This is what they should do next:
    Selectively breed for bigger brains, bigger guts and more babies.
  • by dcigary ( 221160 ) on Friday January 04, 2013 @06:30PM (#42481385) Homepage

    ...a smaller gut for a bigger brain. Alas, it was not meant to be...

    • ... because I don't work so hard. Guppies are so frightfully clever, and they all wear grey. And Goldfish are stupid. Besides, they all wear gold. No, I don't want to play with goldfish children.....

  • by erice ( 13380 ) on Friday January 04, 2013 @06:39PM (#42481545) Homepage

    This doesn't seem very enlightening. If small guts are normally selected against and you specifically breed them, providing they also have large brains, it should come as no surprise that your large brained guppies have smaller guts on average. If all the large brained guppies have smaller guts then brain size and gut size are probably controlled by the same genes: in guppies. That's interesting but not very general.

    I would be more interested to see if they could genetically engineer guppies with large brains and normal size guts and see if they are competitive with their unenhanced cousins. Alternatively, but less conclusively, they could attempt to breed large brained guppies with normal sized guts. A negative result would suggest that either this combination of traits either can not be encoded or does not survive if encoded. How well understood is the guppy genome?

    • If all the large brained guppies have smaller guts then brain size and gut size are probably controlled by the same genes

      It couldn't possibly be resource limitations, i.e. a finite amount of nutrients means that if organ X gets more Y must get less, could it?

  • What the movie "Idiocracy" already taught us...

    "That result suggests that bigger brains are somehow associated with smaller broods "

  • Martian Scientists Breed Big-Brained Apes To Demonstrate Evolution's Trade-Offs

  • ...what does the scientists' octo-parrot think of all this?
  • Did anyone else think that said "puppies"?
  • The large brained fish decided to focus on their careers instead of settling down to raise a family.


    • "we found the male subjects preferred to watch videos of mating while stroking their gonopodiums rather than engaging in intercourse or seeking female fish"

  • If it is artificically introduced, then by definition, it isn't an evolutionary tradeoff.

  • Woah, that was unexpected. I know one of the co-authors and help proofreading the article months ago :-)
  • There are quite a few posts talking about how this isn't natural selection. How it's not evolution. How they should have done this with genetic engineering. How everyone who can write a comment would have done it better than these guys. That's very cute.

    It's important to keep in mind that natural selection will effectively span the full probability space of all possible traits as far as offspring go, and only the strongest survive.

    What that means is twofold:

    1. Given that you're trying to study tradeoff

    • Only those most suited to the current environment survive. Strength has nothing to do with it.

      Also, in the wild, it's more like "Only those most suited living long enough to breed in the current environment have ancesters."

  • I read the article but it didn’t address this. Gene expression takes energy. Large dinosaurs spent a lot of energy on both creating and maintaining their size. We have to assume they had a lot of food available.

    While the larger brain increased cognitive capabilities of the guppies, did it also reduce the fitness of the specimens?

    Would the children of Nepalese sherpas, if raised in lower altitudes, have the same lung capacity of their brethren? It’s a question of gene expression.

    Humans killed

  • Princeton: "Why Intelligence: Object, Stability, Evolution, and Model". I presented an analogical story about why simpler thinking could be better for survival because it allowed faster reaction times. I developed some of those ideas into a couple of conference presentations and made a couple related simulations of self-replicating robots in the late 1980s.

    Then I wrote an (unpublished) essay about it in a PhD grad program at SUNY Stony Brook in Ecology and Evolution around the early 1990s, outlining why Hydras did not have brains, focusing there more on the actual cost to the organism to have a big brain. Not much traction there then. I had another cool idea there about the normal distribution as an ideal search function for an arbitrary discontinuous problem space.

    My wife (who I met in E&E grad school around then) did her graduate thesis work on why foraging theory was wrong because sometimes organisms that made "dumb" decisions would do better than ones that all made "Smarter" decisions that set them in competition with each other. Just today we were discussion this, and I was thinking that for social species, it would make sense for individuals to move to a food source with a probability related to its relative size, so that the population could forage optimally. That might explain aspects of human behavior where people seem to make "dumb" decisions, perhaps also reflected in behavior of troops of bonobos or chimps. I might predict that solitary foragers might do less of that? Probably some PhD or even Nobel Prize in that for someone else. :-)

    Glad to see this kind of research is going mainstream a couple decades later. Back then, especially as I was motivated in this direction by thinking about robotics and AI, such ideas were very far out of the mainstream. They were not rejected so much as mainly ignored or not understood. Plus, I wanted to build what I thought would be a next stage in human (co-)evolution -- the self-replicating space habitat, and that took things way too far...

    I thought about those ideas in part from reading people like Victor Serebriakoff and his book "Brain", Gregory Bateson and "Steps to an Ecology of Mind", Norbert Weiner on Cybernetics and "The Human Use of Human Beings", and "The Selfish Gene" by Richard Dawkins. "The Two Faces of Tomorrow" by James P. Hogan also underlay some bunch of that. And then at my advisor's suggestion because I was looking into this area, "Vehicles: Experiments in Synthetic Psychology" by Valentino Braitenberg (possibly a pre-release copy?) and "Man, Robot and Society: Models and Speculations" by Masanao Toda talking about "The Fungus Eater" robot thought experiment. This was before "Evolutionary Psychology" became a field of its own eventually.

    It is possible that these time, material, heat, and energy costs of computation may define limits that prevents many of the scenarios people outline for various flavors of computational "Singularity". Like everything, intelligence can have diminishing returns depending on the level and the context -- although it might also have threshold where exceeding some level may change the nature of the survival game entirely too.

    Other articles on Slashdot have talked about how individual human intelligence peaked thousands of years ago: []

    Although environment has a lot to do with intelligence, too. And there are ways that today has the most interesting environment in some ways, even if unhealthy diets and lifestyles are probably greatly diminishing intelligence a lot too these days.

  • "the bigger-brained fish also tended to have smaller guts and produce fewer babies."

    Just like humans!

    I have to question the association with size & smarts. 100 years ago in the age of eugenics, there was an effort to measure people- individuals and ethnic groups, and to draw conclusions based on those measurements. There was a general assumption that a large head (and presumably brain) indicated an

  • "But the bigger-brained fish also tended to have smaller guts and produce fewer babies."

    Well, that makes sense. As we all know, educated people have fewer children and often eat healthier.
  • The buried lede: Idiocracy is not species-specific.

Don't tell me how hard you work. Tell me how much you get done. -- James J. Ling