Spiders are intelligent

Why don't you answer mine? Do you want me to start listing the unanswered ones? You want scientific evidence of intelligence without giving your scientific definition of intelligence.You seem to be the only person on the thread who's definitely claiming that spiders have no intelligence, and you're doing so on zero evidence. I keep saying that I'm looking around, and have, as yet, found nothing to tell us whether or not spiders have intelligence. This could be because I haven't looked very far, but it could also be because no one actually knows. So are you. Brains are well known symptoms of intelligence, and if you want to assert that an organism with a brain has no intelligence, then you need to present evidence for that.I present the spider's brain as evidence of its probable intelligence. If you've got complaints, make them in the correct channels, either before or after presenting your first piece of evidence that spiders are complete automatons and your chosen definition of intelligence. Good, you can link to a few that show us that spiders have no intelligence, then, because if there aren't any, you're trying to get me to waste my time searching around. Remember that evidence of instinctual behaviour in an organism is not evidence of no intelligence. All organisms have loads of instincts. Tell me, apart from fuzzy logic, which was your idea, what on the list does the Portia not have?Tell me that, and I promise to explain why spiders must do damage assessment on their webs.

It's good of you to bother. I was mainly reacting to your "answer the question" style of debate by pointing out that you don't always answer questions. Just as I've pointed out that you haven't actually presented evidence of what seems to be your claim, that spiders have no intelligence. I wouldn't mind this, because it's something I haven't found any evidence for either (I'd tell you if I did, I don't care if they're stupid!), but when it's accompanied by strong demands for evidence of the opposite, I have to point it out.I'll try and answer some of your questions.I think we may have been talking at cross purposes for a lot of the thread, and that could well be my fault for not being very clear, so I'll try and clarify.Early on in the thread, you pointed out that the area of the human brain that's the seat of our intelligence doesn't exist in spiders, and I thought that it was a strange comment coming from a biologist, because I'd automatically assumed that that was the case, and that spider brains are the product of a completely different evolutionary history, apart from having a common ancestor hundreds of millions of years ago with some kind of basic nervous system.The reason I talked about convergent evolution was meaning that "intelligence" could arrive along different lineages separately, meaning not similar intelligence, most likely, very, very different. I tried to give an example of likely improvement in intelligence along separate lineages within mammals by pointing out that both we and the dolphins must have increased our brain power since the time of a common ancestor, not expecting anyone to dispute this. Your comment was something to the effect that it should be easy for me to find evidence for that, which I thought odd, because:(a) I assume that if anything with a brain to body ratio like that of ours or the dolphins was known in the fossil record more than 50 million years ago, it would be famous and
(b) There are known ancestor fossils along both lineages with considerably smaller brains than ours and the dolphins.So, though I'm the first to admit to knowing very little paleontology, I thought it pointless to request evidence for what I'd assumed was common knowledge.I understand your view of the spider brain containing "programs", and agree entirely that each species is predisposed to produce a particular type of web. However, that doesn't mean that a small amount of what might be described as intelligence isn't included in the program, because flexibility is a great advantage (if it can be fitted into half a million neurones).What I mean by damage assessment and decision making in relation to webs is that if damage is fairly severe, there's a point when the spider must decide "eat it and start again" or "repair".The reason I don't feel obliged to spend time looking for evidence for that is that I regard it as logically inevitable. Somewhere between complete wipeout and light damage must be a difficult halfway point, so damage assessment and decision making seem to me to have to happen.Having said that, even if I'm right, you can probably still fit this into the instinct category, but I'd comment that it's a clever program, and it would've been perhaps simpler for evolution to have brought a bit of spider intelligence into the proceedings.Now, agreeing that each species is restricted to its web building program doesn't seem to mean much to me, as it is just saying that spider species, like all other species including ourselves, are what they are, and are defined and restricted by their genomes. We can't swing in the trees with the athleticism of the chimps, or lift the weight that a gorilla might. We have to be homo sapiens and can only, by definition, do homo sapiens things, hyper-flexibility and adaptability being very much part of our character.Looking at it that way brings me close to the O.P., but not exactly on sine's point for the moment (I should answer him) because I don't think instinct and intelligence are the same thing, if that's what he literally means, but that it's difficult to define what behaviour is attributable to each category even if we work on agreed definitions, and we haven't even got to that stage on this thread.On to questions, I've said at least twice that I have yet to come up with evidence that will tell us whether or not spiders are intelligent, to which you usually reply that I'm not looking hard enough, presumably meaning that I should have come across all this evidence you're hiding from us which shows that spiders are not intelligent. I think this is where we are at cross purposes, and I'm guessing that you might be confusing evidence of instinct (which all animals have lots of) for evidence of no intelligence.In searches like "spider intelligence instinct", I came across Portia a few times, and Larni put a link to an article on her. So far, I haven't found a better spider to try and make the intelligence case with.Here are the claims I made for spider intelligence, and if I can explain these well in relation to the evidence in that article, that should cover most of the questions you've been asking (although I'm sure it'll provoke more)

quote:

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Spiders:

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(a) Receive knowledge and act on it.

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(b) Use fuzzy logic

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(c) Make decisions

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(d) Can learn from experience, so have memory

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(e) Can carry out long term plans

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(a) I think that's easy. Spider sitting on web receives information via vibrations that a struggling bug has hit the web top half, right of centre, thus gaining the knowledge that a meal awaits it, knowledge that it acts on by going to the area, and eating the thing. Same with broken thread and repair, so I don't think we need bring in Portia.(b) You don't dispute this, but rather that use of logic doesn't require intelligence, using computers as an example. My reply is that computers require our intelligence to do logic, and spiders have no programmers. It would be interesting to hear other people on this. Can something use be said to use logic without having intelligence, anybody?(c) Well, no-one decides where they're going to build their webs for them, plus the decision on whether or not to repair a damaged net, plus Portia's decisions on the best approach or route to her prey.(d) Portia's the best for this, as she'll prefer a particular prey over others once having successfully killed it, and therefore must have it registered on some kind of memory. Also, in the island experiments, she'll try the second of two methods of escape after having failed with the first.(e) Portia again. She'll spend ages planning an approach to a potential victim, and then might take hours to successfully execute the plan, apparently requiring the mapping of a route in her mind and, dare I say it, even imagination.None of this, of course means anything, until we have an agreed thread definition for intelligence, and I doubt we'll get that, or conclusively prove anything one way or the other, but in the meantime, spider behaviour is interesting, so I think it's a worth while thread.{ABE}Don't bother with my questions for the moment until I've answered any more you had that this post hasn't covered - please tell me what they are -cheers}Edited by bluegenes, : see {ABE}Edited by bluegenes, : No reason given.