I study the spiders on the large windows (typically a metre square) round my house. A bug would spend 5 minutes uncontrollably bombarding the window until it blunders into the small web in the corner. The effect of 50 per cent reduction pales in comparison.
If I can find one I will. So far I only relate activities anyone could observe.
Another interesting observation is that only the smaller spiders build their webs on the window. I've noticed that when they get bigger and the web is of comparable size to a window, they build their webs in the open.
(Funny, but at this point they also sit boldly in the centre of their web rather than the edge (great, big, fat things out in the open) and they don't seem to get picked off by birds! Even the cats seem to avoid walking through the webs.)
Matter of opinion, but I don't find your argument coherent.
Sorry, I didn't think I needed to spell it out ... :rolleyes:
If it's about open spaces then bugs also fly into open spaces, hence more bugs.
Hence the evolved behavior to build across open spaces, perhaps that is why I said:
quote:What has likely evolved is a penchant for building webs across open spaces ...
And then noted that both the spider and the bugs could confuse windows and mirrors with open spaces.
Perhaps you intended to say that the spider can't tell the difference between glass and open space, and so is only behaving as normal?
Do you think it can? Ever watch one build a web near a window and intentionally use the window pane?
I don't know about you, but when I observe a fly in a room it spends much more time buzzing against the window than it does against a wall. If I want to swat the fly, I stand by the window.
Because the fly obviously sees the window as an open space. Just as the spider does.
The fact that the spider never learns to stop building there when the windows are cleaned speaks against intelligence in making that choice.
I also find that the number of flies is greater outdoors than indoors, so an intelligent spider would stay outdoors eh? More flies, fewer cleaned windows, higher yield for less expenditure of energy.
Do you think it can? Ever watch one build a web near a window and intentionally use the window pane?
Yes.
How would you determine intention in a spider, apart from subjectively?
Spiders build webs (nearly) against windows. I have observed that the ratio of web area to window does not get to 50 per cent. Even though it would seem very convenient, I have never seen a web that filled a whole window. As was mentioned a web > 50 per cent of the window area would be counterproductive, and I have never seen it happen even though it would seem convenient. But webs the equivalent size can be seen in the open.
Also, I observe the webs near the wing mirror of my car, tend to be next to, rather than over the mirror. So, I cannot see how the open space thing applies here. Also, there is just as much open space by the wheels for example, but I don't see webs there. Building a small web next to, rather than over, a small mirror greatly increases the effective catchment area, given the behaviour of bugs.
I also find that the number of flies is greater outdoors than indoors, so an intelligent spider would stay outdoors eh? More flies, fewer cleaned windows, higher yield for less expenditure of energy.
Yes. The webs I observe are outside the window. Being see-through I am able to see from the inside. Enjoy.
The fact that the spider never learns to stop building there when the windows are cleaned speaks against intelligence in making that choice.
(Outside is not cleaned that regularly.) In any case, it is the same with humans. Our intelligent choices can have unintelligent aspects (choosing junk food is still an intelligent choice in the sense people are talking about it here).
Because the fly obviously sees the window as an open space. Just as the spider does.
But then you'd expect to see some webs that span the whole window. I don't see any.
Look. A spider's brain is smaller than the head of a pin.
Limits of scale place a ceiling on how flexible an animal's behavior can become, because smaller animals have fewer, not smaller, neurons.
Fewer components for a brain means that fewer neurons are available for sensory organs, problem-solving mechanisms, and cognitive/behavioral flexibility. This is a fundamental engineering problem. It limits how complex or flexible those systems can become.
A robot spider would have to do so much, I doubt anybody is anywhere near making one.
Wrong.
The web-building behaviour of orb-web-building spiders provides an excellent example of an organism solving a complex task of spatial orientation by the iterated application of simple local behaviour patterns. Thus, one can model the garden cross spider Araneus diadematus as a virtual ‘spider robot’ in order to explore and modify the spatial world of digitized spider webs. Such an approach shows that a small number of very simple behaviour patterns are sufficient to generate accurately the characteristics of a real spiderweb.
Spiders’ webs Current Biology, Volume 15, Issue 10, Pages R364-R365
This paper is concerned with the walking behavior strategy of a spider-robot for the realization of walking of, e.g. creatural spiders. A creatural spider responds to environmental information by adapting various walking forms, in the cases of escaping from natural enemies or fear, being chased and so on. This research uses fuzzy theory and neural networks. The mechanism of these walking behaviors is examined and verified through simulation and experiment.
Walking behavior of spider-robot with adaptation for environment information SICE 2004 Annual Conference Volume 3, p. 1999-2003
It would have to be able to spin a web in a random geometry...
Wrong. The geometry is not random.
Web and behavior are so closely linked that it is possible to deconstruct the web structure not only to provide a continuous record of the visible steps taken by the spider but also to infer from this visible record the underlying and hidden rules that are guiding these steps (Eberhard 1969;Gotts & Vollrath 1992;Krink & Vollrath 1997, 1998, 1999). A prerequisite for a successful behavioral dissection is a very good understanding of both, web engineering and spider activity (Eberhard 1981, 1986, 1988a,b; Heiling & Herberstein 1998;Herberstein & Heiling 1999;Vollrath 1987, 1988, 1992a; Vollrath et al. 1997). Fortunately, the modern techniques of filming and movement analysis are making this increasingly easy (Benjamin & Zschokke 2002, 2003; Zschokke & Vollrath 1999a) and accessible to modern simulation and modeling tools (Gotts & Vollrath 1992;Krink & Vollrath 1997, 1998, 1999, 2000).
Web architecture is principally static with a semipermanent geometry, although its functional engineering is dynamic (Lin et al. 1995).
The typical orb web consists of a flat wheel of stiff radial threads overlaid by a spiral of elastic and sticky threads suspended freely in vegetation from a few guy lines. Radials and spiral often show distinct asymmetries in shape and spacing typically associated with a vertical orientation of the web and constituting a fine-tuning to maximize prey capture (Vollrath et al. 1997). In order to orient in the web, the spider uses vibrations but also the direction of illumination, which, together with gravity provides a general compass direction (Vollrath 1992). In addition to hand-railing along existing threads and orienting by a set of rather simple decision rules (Krink & Vollrath 1999), some orb weavers also navigate using idiothetic path integration (Vollrath et al. 2000).
The Role of Behavior in the Evolution of Spiders, Silks, and Webs Annual Review of Ecology, Evolution, and Systematics December 2007, Vol. 38, Pages 819-846
For example, mating dances and chemical signalling. We probably don't even have any idea of the complexity of these.
Wrong.
Chemical Signaling in a Wolf Spider: A Test of Ethospecies Discrimination Journal of Chemical Ecology Volume 30, Number 6 / June, 2004
There are over 5000 papers on chemical signalling.
An Analysis of Alternative Mating Tactics of the Jumping Spider Phidippus johnsoni (Araneae, Salticidae) Journal of Arachnology, Vol. 5, No. 3 (Autumn, 1977), pp. 185-230
You do realize, of course, that you are suggesting that every animal on this planet, vertebrate and invertebrate, shares a common neurobiological system?
I certainly never suggested that. But they're all part of the same DNA based life system. When you say that spiders are "hard wired" to be what they are and to do what they do, I agree. I just think that we are genetically hard wired as well.
Evolution only acts on phenotypes. Which means you need to offer a neurobiological explanation of spider intelligence.
Isn't the nervous system part of the phenotype? Is there something known in biology that indicates that only mammals can evolve intelligence? Do you think that neurobiologists have an advanced understanding of spiders at this point in time? I'll look around.
As for asking me to search for scientific papers to back up my comments on language and the word intelligence, I'm waiting for your scientific definition of intelligence. Remember, if it's an agreed definition amongst scientists, then I'm the one who backs your right for its use on a science thread, and I'll be perfectly happy to agree that spiders are not intelligent according to the scientific usage of the word if that proves to be the case.
It won't actually mean much, other than that scientists have decided to give the word a very narrow meaning.
molbiogirl writes:
bluegenes writes:
Not having that level of extraordinary adaptive ability doesn't mean they have none.
Then please find evidence that supports your assertion.
One anecdotal account of "taming" a tarantula simply will not do.
That's actually a rational statement, not an assertion. You could've accuse me of stating the obvious, though. Presumably you mean my assertion that spiders have some level of ability to adapt to new situations, which I probably made elsewhere in the thread. Their webs are constantly being damaged in many different ways. They seem to assess the damage, and make repairs accordingly. Pointing out that they're hard wired to do this is like pointing out that we're hard wired to educate our children, that it's a characteristic of the species. Both processes require intelligence in the non-scientific sense of the word.
I gave one of the common definitions of intelligence:
"The capacity to acquire and apply knowledge."
You don't need scientific papers to fit spiders to that, any more than you need scientific papers to know that they've got eight legs, so if this were a coffee house thread instead of a science thread, I'd have a good case.:)
I certainly never suggested that. But they're all part of the same DNA based life system. When you say that spiders are "hard wired" to be what they are and to do what they do, I agree. I just think that we are genetically hard wired as well.
Look. I asked for you to support your assertions.
I gave you two sites where you can do your research.
Define "the system". Provide evidence of this system in spiders. Provide evidence of convergent evolution of this system. Provide evidence of hard wiring. Provide evidence that intelligence is relative. Provide evidence of the adaptability of spiders.
I have asked for each of these before. Please stop avoiding the questions.
As for asking me to search for scientific papers to back up my comments on language and the word intelligence, I'm waiting for your scientific definition of intelligence.
You know what? I'm holding out despite Sin's refusal to cough up a definition. I still have hope that another Admin will point out that in a science thread, Sin has a responsibility to define intelligence. The name of the topic is "Spiders are intelligent" for pete's sake.
I gave one of the common definitions of intelligence:
"The capacity to acquire and apply knowledge."
You don't need scientific papers to fit spiders to that, any more than you need scientific papers to know that they've got eight legs, so if this were a coffee house thread instead of a science thread, I'd have a good case.
Come on, Blue. You know perfectly well that a dictionary definition is not sufficient.
Why on god's green earth would we bother with neuroscience and evolutionary biology if we could just pluck a definition from Webster's and go, "Yup. Spiders fit."
I think that if someone wanted to claim that an animal with a brain that exhibits complex behaviour has no intelligence, then that would be the assertion that requires support.
Here's an interesting title of a scientific paper for you.
Title: The Intelligence of the American Turret Spider Publication: Science, Volume 2, Issue 23, pp. 43-44 Publication Date: 07/1883 Origin: JSTOR Bibliographic Code: 1883Sci.....2R..43.
Unfortunately, I can't access it.
Now, let's have that concensus scientific definition of intelligence, shall we?
(I agree with you that sine should offer definitions).
I really need this mysterious scientific definition of intelligence in order to see if I agree with you or not.
The Intelligence of the American Turret Spider ... 1883
Oh for feck's sake, Blue. 1883?
I think that if someone wanted to claim that an animal with a brain that exhibits complex behaviour has no intelligence, then that would be the assertion that requires support.
:o :laugh: I didn't notice the date, just laughed at the title and put it in. Sorry about that.
Did you look at Message 96?
Yes. But notice that I'm not using their basic web building instincts as an example of flexible behaviour, but rather their ability to identify unpredictable damage and repair it.
I also agree entirely that small brains severely limit flexibility, but that doesn't mean zero flexibility or zero intelligence.
Remember, I'm the first to agree that they won't get by as intelligent if we use a narrow definition, which is why we need to define the word for the purposes of the thread.
Yes. But notice that I'm not using their basic web building instincts as an example of flexible behaviour, but rather their ability to identify unpredictable damage and repair it.
I'm not sure why this is a problem. Damage is just a break in the strand (or some such). Why wouldn't the weaving "program" not suffice?
In a way, I agree that it's part of the program, but it appears that the spiders are programmed to improvise what appear to be intelligent solutions, and this raises the question of whether or not a bit of "intelligence" has been included in the program.
Have a read of the link that I put in earlier to this spider enthusiast. Not the first bit, but where he describes two web repairing incidents.
The thing is that all animal intelligence, presumably, must start from "programs". If, as in our ancestry, the organism evolves the ability to innovate, then can't that be seen as the result of a complex and "clever" step in the evolution of the program. Isn't it hard to define a point when animals can be seen as biological automatons, and when they start thinking for themselves?
In a way, I agree that it's part of the program, but it appears that the spiders are programmed to improvise what appear to be intelligent solutions, and this raises the question of whether or not a bit of "intelligence" has been included in the program.
We must be talking past one another.
To build the web, spiders use gravity and the direction of light. To repair the web they do the same thing.
I read the link. No surprises there. Damage repair is identical to web building.
How is it different? How is doing a second time what they did the first time improvisation?
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