5 ms·

“Considering that spiders can already make really impressive geometric designs with their webs, it’s no surprise that they can take that leap to make an impress

by smtf 14y ago

“Considering that spiders can already make really impressive geometric designs with their webs, it’s no surprise that they can take that leap to make an impressive design with debris and other things,” Sure, but what is more interesting is how such a spider would know what itself looks like.

seiji 14y ago
"know" is a bit of a strong word here. Does a printer "know" what a W is or does it just know where to put the dots?
- TeMPOraL 14y ago
  Not that strong. For printer, the shape of a W is an external input. This spider outputs something resembling its own shape. So the question is here, why this and not something else (like randomly shaped clump), and how did it acquire this particular decoy blueprint.
  - glhaynes 14y ago
    How about a printer with a picture of itself built-in as a test page pattern? :) I'd guess that its sculptures started as fairly undefined clumps that served the purpose somewhat well (presumably that's what's built by other "sculpting spiders" that the article mentions?). And then evolution has refined that clump, like it does so well.
  - popopje 14y ago
    because one with legs is a more effective decoy? (or whatever other implications a larger spider has)
  - seiji 14y ago
    Let me channel dawkins (and/or sagan) for a moment: Imagine there's a cluster of spiders and a cluster of predators of those spiders. The predators can directly grab the spider, but if it fails and gets caught in the web, the spider wins. The predator is pattern matching on "what looks like a spider." Maybe a few spider brains create reliable glitches in their webs. Maybe the glitches look enough like not-web where some predators get caught in the web when trying to catch the non-spider. The uneaten spiders-with-web-glitches reproduce and create further glitch making spiders. The predators not caught in the web (i.e. not fooled by the web glitch) also reproduce (n.b. the predators are reproducing glitch-avoiding pattern matching, so we have a glitch-vs-anti-glitch brain race), and some new spiders have more glitchy mutations making bigger anomalies. The anomalies looking more spider like will attract predators, and those spiders won't be eaten as easily. The uneaten spiders can reproduce more glitch-making spiders. The uneaten prey can reproduce more glitch-avoiding prey. The steady state of this model ends up with spiders reproducing themselves so the predator needs more and more advanced web glitch detection. Let this cycle go on for unbelievably long time scales (thousands? tens of thousands? hundreds of thousands? millions of years?), and you have a predator-prey derived "art." The spider doesn't "know" it's intentionally making decoy spiders. It's just evaluating it's internal tiny spider brain state machine with evolutionarily derived glitches over the past ginormous number of years.
    - mkeener 14y ago
      Yes, Exactly! Another similar example would be the process that produced the heikegani crab. TL;DR - Over years fishermen threw crabs with face-like patterns on their carapaces back into the ocean. Over time this produced crabs with extremely detailed faces, increasing the chances they wouldn't be eaten and could reproduce. http://en.wikipedia.org/wiki/Heikegani http://en.wikipedia.org/wiki/Heikegani
      - btilly 14y ago
        If you read your link, you'd find that Carl Sagan's theory is doubtful.
    - bonobo 14y ago
      We often hear about how long mammals' or birds' characteristics took to evolve, I'd like to have a grasp of the scale of time we're dealing with when talking about tiny creatures like these. I have absolutely no idea of the time that is necessary for such characteristic to evolve, but I think it's not that much time when talking about insects or arachnids. Evolution is not iterated over time, it happens over generations. And when talking about insects or arachnids, we have a lot of them in a short span of time.
      - hfsktr 14y ago
        You raise an interesting topic I've never really given much thought to (time vs generations). Makes me think of other questions about genetics that I just don't know the answers to but that someone must have thought of. Things like: How do they account for recessive traits? Can something that is recessive become dominant? Can something dominant just disappear (I imagine that it could with mutations happening so much)? Is there a specific animal they use to test these things? Do different traits take longer to evolve towards? I imagine they use something that reproduces rapidly (fruit flies? fleas?). On the topic of this spider and how does it know what it looks like...I don't know how much brainpower the spiders have but I know that we have a part of the brain that tracks where our body is (at least in relation to other body parts). Is it possible the spiders have something similar? Can this even be used to make a rough representation of oneself? I am going to have to google some of these later as I'm now curious.
  - ceejayoz 14y ago
    Natural selection, over millions of years. Slightly more spider-like decoys get selected for.
skc 14y ago
Having trouble viewing the video but what's blowing my mind right now is that in the picture I see, it has created a decoy with 8 legs. How does it know??
- robotresearcher 14y ago
  The writer/editor chose that picture. Scroll down and there's a 5-legged decoy. It's still cool, but they chose the most impressive picture to lead with.
  - skc 14y ago
    Ah yes. Though I guess the spider could argue it isn't done sculpting yet.
  - takluyver 14y ago
    Looks like it. If one clicks through to the blog post, there are photos of two more decoys, both with <8 legs. But I guess most predators don't stop to count legs, so the evolutionary pressure for better decoys isn't that high.
solox3 14y ago
More likely the case is it knows what its mother looks like.
- solox3 14y ago
  What? it's not a "yo mama" joke. Many species of spiders show parental care: http://i.imgur.com/Ayrsv.jpg http://i.imgur.com/Ayrsv.jpg
  - loopdoend 14y ago
    So it turns out iPads make for dangerous projectiles. Let this be a fair warning to others.
    - nitrogen 14y ago
      Apparently spiders aren't the only ones with a long history of evolved behavior; before I even recognized what I was looking at, I had an immediate "WTF?!?!?!?!" fight or flight response to that fascinating image of a mother spider with many tiny spiders on its back.
jre 14y ago
Some mussels have evolved a similar feature : they are able to make part of them look like a fish even if they are blind : http://whyevolutionistrue.wordpress.com/2011/03/02/amazing-mimics-the-mussel-lampsilis/ http://whyevolutionistrue.wordpress.com/2011/03/02/amazing-m... Probably those spiders are the result of a similar evolutionary process.
mediocregopher 14y ago
For even more mind-blowing, a mussel that looks like a fish: http://unionid.missouristate.edu/gallery/L_reeveiana/Reeviana.htm http://unionid.missouristate.edu/gallery/L_reeveiana/Reevian... EDIT: looks like jre beat me to it
robotresearcher 14y ago
It doesn't. It just likes to stick bits to its web in patterns. Feels good, (spider) man. Something like this: 1. get bit of leaf. 2. go to center of web. 3. while standing on leaf bits, go down (with G). 4. drop bit of leaf, leaving gap to the left and right. 5. if more than 20 paces from the center. Forget it, relax. 6. goto 1. With a bit of fiddling I have no doubt you can write a simple program to produce these shapes. If you find this interesting, check YouTube for termite and wasp nest videos. Incredible!
- mirkules 14y ago
  The process of producing decoy shapes isn't really a problem. Why these spiders made the shapes is more interesting. I think that the spiders that didn't create these decoy structures were selected against in the evolutionary process. The production of decoys could have been genetically engrained into their instinct (via mutation), or, this species really are actually able to recognize itself and create a decoy -- both of these cases would have led to less of them being eaten by predators, hence natural selection. I can't wait to hear the results of the study after they research it more closely!
  - robotresearcher 14y ago
    Which of these explanations seems more likely, in the context of a spider? Spiders are very smart for their size (up to 80% of their body cavity is brain, and much larger than for insects), but giving them theory of mind is a stretch. "That guy there wants to eat me. I look like this. If I make a thing that looks like me, he will think it's me and try to eat that, and I'll be safer." vs. I just love to get bits of leaf and stick them just so!
    - mirkules 14y ago
      Sure, it's a stretch, I don't dispute that at all. Maybe a spider witnessed another spider being eaten, and since it was spared, decided to make another spider-looking thing so it doesn't get eaten again. It's not really a matter of self-recognition or theory of mind, but more of a pattern recognition, something spiders (I assume) are good at. "My friend was eaten, and I wasn't. I should make something that looks like my friend so I don't get eaten." But, then again, Occam's Razor and all that. :)
Someone 14y ago
It doesn't have to know what it looks like; it only needs to "know" what its predator's food looks like, or rather, what its predators are more likely to hunt. And that probably is "know", as in "built into its genes through evolutionary trial and error". It is not likely this is something mothers learn their children, or that they adapt the looks of their decoys within days if researchers let new predators loose (either might be true, but would truly be surprising)
CamperBob2 14y ago
It would be interesting to amputate a leg from the spider in infancy and see if it creates a seven-legged simulacrum as an adult.
- jayflux 14y ago
  Spiders legs grow back when you remove a leg from them.
  - andrewflnr 14y ago
    Really? I'm pretty sure that's not true. I think I would have heard about it when I went through one of my spider-fascination phases.
ry0ohki 14y ago
A spider has to instinctively know what a spider looks like, otherwise how would it know what to mate with?
- Fargren 14y ago
  Do the mate with each other or do they lay and impregnate eggs?
  - nitrogen 14y ago
    They mate somewhat directly: https://en.wikipedia.org/wiki/Spider#Reproduction_and_life_cycle https://en.wikipedia.org/wiki/Spider#Reproduction_and_life_c...
- VMG 14y ago
  Knowing what it looks like doesn't mean knowing how to build it.
brudgers 14y ago
Looking at the original article, it appears that the most spider like decoy photograph was chosen based on the appearance to humans - i.e. one with 8 legs which presumably you counted just as I did. http://blog.perunature.com/2012/12/new-species-of-decoy-spider-likely.html http://blog.perunature.com/2012/12/new-species-of-decoy-spid... What appears spider-like to a fly, could be dramatically different - I'm imagining the process of trying to count appendages through a compound eye with a fly's brain and in the absence of the cultural system of symbols we use to represent numbers, etc. See Thomas Nagel's What is it Like to Be a Bat? http://books.google.com/books?id=fBGPBRX3JsQC&pg=PA165#v=onepage&q&f=false http://books.google.com/books?id=fBGPBRX3JsQC&pg=PA165#v...
- return0 14y ago
  Flies are not predators for spiders.
pron 14y ago
I would recommend reading "Sex on Six Legs: Lessons on Life, Love, and Language from the Insect World" by Marlene Zuk. It's a truly wonderful book about insects (and spiders too), about their evolution, and about how little brain power is required to display complex behavior. Here are a few of my favorite, more on the philosophical side, quotes from the book: Insects bring home the uneasy truth that you don't need a big brain to do big things, and that in turn makes us question how the mind and, dare to say it, the spirit, are related to the brain. It even makes us question what it means to be human. What does it mean to have complex behavior? Does it mean you are smart? Natural selection can produce what looks uncannily like intelligent thought or emotion but is no more than the relentless culling of minute variations in genetic makeup, generation after generation, for millions of years. Not only that, but insects too have small personalities, with some showing boldness in new situations and some hanging back with what looks an awful lot like shyness. It's turning out that we haven't cornered the market on individuality, either. Insects are starting to answer the question of "What does it take?"—to have a personality, to learn, to teach others, to change the world around them—with the humbling and perplexing answer, "Not much." Humbling because they do these things with brains the size of a pinhead, and perplexing because if that's all it takes, what does that mean for us, with our gigantic forebrains and exhaustingly long periods of childhood dependency?
- pagliara 14y ago
  Thank you for the recommendation. You've inspired me to go read this right now.
6ren 14y ago
There's no need for the spider to know what itself looks like. If it builds something that increases survival/reproduction, that trait will be selected for. The spiders’ webs were crafted around face-height, near the trail This makes me wonder if it was selected for stopping humans from wrecking their webs! It would explain why the decoys look like spiders, to humans.
- deleted 14y ago
  [deleted]
- VMG 14y ago
  way too little time to evolve that behavior

by smtf 14y ago

seiji 14y ago

"know" is a bit of a strong word here. Does a printer "know" what a W is or does it just know where to put the dots?

TeMPOraL 14y ago
Not that strong. For printer, the shape of a W is an external input. This spider outputs something resembling its own shape. So the question is here, why this and not something else (like randomly shaped clump), and how did it acquire this particular decoy blueprint.
- glhaynes 14y ago
  How about a printer with a picture of itself built-in as a test page pattern? :) I'd guess that its sculptures started as fairly undefined clumps that served the purpose somewhat well (presumably that's what's built by other "sculpting spiders" that the article mentions?). And then evolution has refined that clump, like it does so well.
- popopje 14y ago
  because one with legs is a more effective decoy? (or whatever other implications a larger spider has)
- seiji 14y ago
  Let me channel dawkins (and/or sagan) for a moment: Imagine there's a cluster of spiders and a cluster of predators of those spiders. The predators can directly grab the spider, but if it fails and gets caught in the web, the spider wins. The predator is pattern matching on "what looks like a spider." Maybe a few spider brains create reliable glitches in their webs. Maybe the glitches look enough like not-web where some predators get caught in the web when trying to catch the non-spider. The uneaten spiders-with-web-glitches reproduce and create further glitch making spiders. The predators not caught in the web (i.e. not fooled by the web glitch) also reproduce (n.b. the predators are reproducing glitch-avoiding pattern matching, so we have a glitch-vs-anti-glitch brain race), and some new spiders have more glitchy mutations making bigger anomalies. The anomalies looking more spider like will attract predators, and those spiders won't be eaten as easily. The uneaten spiders can reproduce more glitch-making spiders. The uneaten prey can reproduce more glitch-avoiding prey. The steady state of this model ends up with spiders reproducing themselves so the predator needs more and more advanced web glitch detection. Let this cycle go on for unbelievably long time scales (thousands? tens of thousands? hundreds of thousands? millions of years?), and you have a predator-prey derived "art." The spider doesn't "know" it's intentionally making decoy spiders. It's just evaluating it's internal tiny spider brain state machine with evolutionarily derived glitches over the past ginormous number of years.
  - mkeener 14y ago
    Yes, Exactly! Another similar example would be the process that produced the heikegani crab. TL;DR - Over years fishermen threw crabs with face-like patterns on their carapaces back into the ocean. Over time this produced crabs with extremely detailed faces, increasing the chances they wouldn't be eaten and could reproduce. http://en.wikipedia.org/wiki/Heikegani http://en.wikipedia.org/wiki/Heikegani
    - btilly 14y ago
      If you read your link, you'd find that Carl Sagan's theory is doubtful.
  - bonobo 14y ago
    We often hear about how long mammals' or birds' characteristics took to evolve, I'd like to have a grasp of the scale of time we're dealing with when talking about tiny creatures like these. I have absolutely no idea of the time that is necessary for such characteristic to evolve, but I think it's not that much time when talking about insects or arachnids. Evolution is not iterated over time, it happens over generations. And when talking about insects or arachnids, we have a lot of them in a short span of time.
    - hfsktr 14y ago
      You raise an interesting topic I've never really given much thought to (time vs generations). Makes me think of other questions about genetics that I just don't know the answers to but that someone must have thought of. Things like: How do they account for recessive traits? Can something that is recessive become dominant? Can something dominant just disappear (I imagine that it could with mutations happening so much)? Is there a specific animal they use to test these things? Do different traits take longer to evolve towards? I imagine they use something that reproduces rapidly (fruit flies? fleas?). On the topic of this spider and how does it know what it looks like...I don't know how much brainpower the spiders have but I know that we have a part of the brain that tracks where our body is (at least in relation to other body parts). Is it possible the spiders have something similar? Can this even be used to make a rough representation of oneself? I am going to have to google some of these later as I'm now curious.
- ceejayoz 14y ago
  Natural selection, over millions of years. Slightly more spider-like decoys get selected for.

skc 14y ago

Having trouble viewing the video but what's blowing my mind right now is that in the picture I see, it has created a decoy with 8 legs. How does it know??

robotresearcher 14y ago
The writer/editor chose that picture. Scroll down and there's a 5-legged decoy. It's still cool, but they chose the most impressive picture to lead with.
- skc 14y ago
  Ah yes. Though I guess the spider could argue it isn't done sculpting yet.
- takluyver 14y ago
  Looks like it. If one clicks through to the blog post, there are photos of two more decoys, both with <8 legs. But I guess most predators don't stop to count legs, so the evolutionary pressure for better decoys isn't that high.

solox3 14y ago

More likely the case is it knows what its mother looks like.

solox3 14y ago
What? it's not a "yo mama" joke. Many species of spiders show parental care: http://i.imgur.com/Ayrsv.jpg http://i.imgur.com/Ayrsv.jpg
- loopdoend 14y ago
  So it turns out iPads make for dangerous projectiles. Let this be a fair warning to others.
  - nitrogen 14y ago
    Apparently spiders aren't the only ones with a long history of evolved behavior; before I even recognized what I was looking at, I had an immediate "WTF?!?!?!?!" fight or flight response to that fascinating image of a mother spider with many tiny spiders on its back.

jre 14y ago

Some mussels have evolved a similar feature : they are able to make part of them look like a fish even if they are blind : http://whyevolutionistrue.wordpress.com/2011/03/02/amazing-mimics-the-mussel-lampsilis/ http://whyevolutionistrue.wordpress.com/2011/03/02/amazing-m... Probably those spiders are the result of a similar evolutionary process.

mediocregopher 14y ago

For even more mind-blowing, a mussel that looks like a fish: http://unionid.missouristate.edu/gallery/L_reeveiana/Reeviana.htm http://unionid.missouristate.edu/gallery/L_reeveiana/Reevian... EDIT: looks like jre beat me to it

robotresearcher 14y ago

It doesn't. It just likes to stick bits to its web in patterns. Feels good, (spider) man. Something like this: 1. get bit of leaf. 2. go to center of web. 3. while standing on leaf bits, go down (with G). 4. drop bit of leaf, leaving gap to the left and right. 5. if more than 20 paces from the center. Forget it, relax. 6. goto 1. With a bit of fiddling I have no doubt you can write a simple program to produce these shapes. If you find this interesting, check YouTube for termite and wasp nest videos. Incredible!

mirkules 14y ago
The process of producing decoy shapes isn't really a problem. Why these spiders made the shapes is more interesting. I think that the spiders that didn't create these decoy structures were selected against in the evolutionary process. The production of decoys could have been genetically engrained into their instinct (via mutation), or, this species really are actually able to recognize itself and create a decoy -- both of these cases would have led to less of them being eaten by predators, hence natural selection. I can't wait to hear the results of the study after they research it more closely!
- robotresearcher 14y ago
  Which of these explanations seems more likely, in the context of a spider? Spiders are very smart for their size (up to 80% of their body cavity is brain, and much larger than for insects), but giving them theory of mind is a stretch. "That guy there wants to eat me. I look like this. If I make a thing that looks like me, he will think it's me and try to eat that, and I'll be safer." vs. I just love to get bits of leaf and stick them just so!
  - mirkules 14y ago
    Sure, it's a stretch, I don't dispute that at all. Maybe a spider witnessed another spider being eaten, and since it was spared, decided to make another spider-looking thing so it doesn't get eaten again. It's not really a matter of self-recognition or theory of mind, but more of a pattern recognition, something spiders (I assume) are good at. "My friend was eaten, and I wasn't. I should make something that looks like my friend so I don't get eaten." But, then again, Occam's Razor and all that. :)

Someone 14y ago

It doesn't have to know what it looks like; it only needs to "know" what its predator's food looks like, or rather, what its predators are more likely to hunt. And that probably is "know", as in "built into its genes through evolutionary trial and error". It is not likely this is something mothers learn their children, or that they adapt the looks of their decoys within days if researchers let new predators loose (either might be true, but would truly be surprising)

CamperBob2 14y ago

It would be interesting to amputate a leg from the spider in infancy and see if it creates a seven-legged simulacrum as an adult.

jayflux 14y ago
Spiders legs grow back when you remove a leg from them.
- andrewflnr 14y ago
  Really? I'm pretty sure that's not true. I think I would have heard about it when I went through one of my spider-fascination phases.

ry0ohki 14y ago

A spider has to instinctively know what a spider looks like, otherwise how would it know what to mate with?

Fargren 14y ago
Do the mate with each other or do they lay and impregnate eggs?
- nitrogen 14y ago
  They mate somewhat directly: https://en.wikipedia.org/wiki/Spider#Reproduction_and_life_cycle https://en.wikipedia.org/wiki/Spider#Reproduction_and_life_c...
VMG 14y ago
Knowing what it looks like doesn't mean knowing how to build it.

brudgers 14y ago

Looking at the original article, it appears that the most spider like decoy photograph was chosen based on the appearance to humans - i.e. one with 8 legs which presumably you counted just as I did. http://blog.perunature.com/2012/12/new-species-of-decoy-spider-likely.html http://blog.perunature.com/2012/12/new-species-of-decoy-spid... What appears spider-like to a fly, could be dramatically different - I'm imagining the process of trying to count appendages through a compound eye with a fly's brain and in the absence of the cultural system of symbols we use to represent numbers, etc. See Thomas Nagel's What is it Like to Be a Bat? http://books.google.com/books?id=fBGPBRX3JsQC&pg=PA165#v=onepage&q&f=false http://books.google.com/books?id=fBGPBRX3JsQC&pg=PA165#v...

return0 14y ago
Flies are not predators for spiders.

pron 14y ago

I would recommend reading "Sex on Six Legs: Lessons on Life, Love, and Language from the Insect World" by Marlene Zuk. It's a truly wonderful book about insects (and spiders too), about their evolution, and about how little brain power is required to display complex behavior. Here are a few of my favorite, more on the philosophical side, quotes from the book: Insects bring home the uneasy truth that you don't need a big brain to do big things, and that in turn makes us question how the mind and, dare to say it, the spirit, are related to the brain. It even makes us question what it means to be human. What does it mean to have complex behavior? Does it mean you are smart? Natural selection can produce what looks uncannily like intelligent thought or emotion but is no more than the relentless culling of minute variations in genetic makeup, generation after generation, for millions of years. Not only that, but insects too have small personalities, with some showing boldness in new situations and some hanging back with what looks an awful lot like shyness. It's turning out that we haven't cornered the market on individuality, either. Insects are starting to answer the question of "What does it take?"—to have a personality, to learn, to teach others, to change the world around them—with the humbling and perplexing answer, "Not much." Humbling because they do these things with brains the size of a pinhead, and perplexing because if that's all it takes, what does that mean for us, with our gigantic forebrains and exhaustingly long periods of childhood dependency?

pagliara 14y ago
Thank you for the recommendation. You've inspired me to go read this right now.

6ren 14y ago

There's no need for the spider to know what itself looks like. If it builds something that increases survival/reproduction, that trait will be selected for. The spiders’ webs were crafted around face-height, near the trail This makes me wonder if it was selected for stopping humans from wrecking their webs! It would explain why the decoys look like spiders, to humans.

deleted 14y ago
[deleted]
VMG 14y ago
way too little time to evolve that behavior