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Camouflage in nature

Discussion of everything related to the Theory of Evolution.

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Re: Camouflage in nature

Postby Nick7 » Sat Nov 12, 2011 7:36 pm

Gavin,

I saw that video (thanks) – that’s where I pulled the eye example from. Dawkins’ explanation of the camouflage development there didn’t really impress me. He states that mimic creatures had a chance (time wise) to evolve at the beginning (before the completion of the camouflage) because the seeing conditions for the birds were poor (then what’s the incentive to evolve a complex camouflage if the current system works anyway?) But it doesn’t matter...

Pardon me for disagreeing, but I don’t think I was wrong about the process and probabilities. I never stated that the perfection process is not cumulative. I have not disagreed with what Dawkins called in that video “opening of gradualistic lock”. YES, with each successful outcome the bug retains it, no doubt. What I said was that each successful outcome is not statistically dependent from the previous one. In other words, the greener bug is statistically as probable to produce a browner offspring as the greener ones (when mutation does actually occur). The only thing is… the browner ones will die out and the greener ones will survive passing on their genes of increased greeneshness. That’s a simple statistics. If I ask you to pull a lucky 7 of hearts out of the deck and you succeed, I’ll give you a dollar (that’s accumulation of your luck). But once I put that 7 back into the deck, your chance of pulling it out again is absolutely the same. If your goal is to accumulate $10, you will get there, but the pace is still going to be the same with each successive outcome (the accumulation of luck is not random, but the luck itself is). So the process will not accelerate, and still will be as slow as it can get in accumulation of extra greeneshness (as well as other necessary qualities). Am I wrong again?

That’s what I was concerned about - time. How frequent are mutations in nature and how frequent are beneficial ones anyway? If you are trying to mimic an alive organism it will be a very lengthy process, and if alive organism changes too, then you do not have your “gradualistic lock” anymore – the combinations initially unlocked may change by the time you open the entire lock. That’s why I initially stated the object you are trying to mimic has got to be at least relatively genetically stable, and that’s what you seem to confirm in your last post (the tree leaves will not change as fast as bugs).

So it does seem to me that evolution through natural selection applied to camouflage will not work in a system with multiple degrees of freedom – the benchmark creature should not alter its qualities (or at least shouldn’t do it too fast) or one will not be able to reach a state of a perfect camouflage.

The bug – tree system – that seems to work (the tree is a pretty stable benchmark). This is another one - Phengaris rebeli ( http://en.wikipedia.org/wiki/Phengaris_rebeli ). This amazing creature imitates at least 2 qualities of ants (scent and sound signals emitted by queen ants). I would be interested to know how this system worked out with 2 similar biological organisms. Did the dependency start before the time was time, and the Phengaris rebeli was just maintaining these qualities in real time, keeping up with the ants or it managed to catch up with the ants later on through unlocking a “gradualistic lock”?


P.S. Anyway, feel free to disengage whenever you want (in any case it was a very productive experience to me). I might be too stubborn and ignorant for these types of conversations.
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Re: Camouflage in nature

Postby Gavin » Sun Nov 13, 2011 3:31 pm

Nick7 wrote:So it does seem to me that evolution through natural selection applied to camouflage will not work in a system with multiple degrees of freedom – the benchmark creature should not alter its qualities (or at least shouldn’t do it too fast) or one will not be able to reach a state of a perfect camouflage.

Since camouflage and mimicry exist, what's the alternative?
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Re: Camouflage in nature

Postby Nick7 » Mon Nov 14, 2011 8:37 pm

Gavin,

The development of life from the beginning of time to now explained by evolution through natural selection is not a fact, but a hypothesis which has been proven with the highest level of probability possible. But there is so much complexity in life, that the luck’s role in the creation of such a high level of order will always be questioned (and rightfully so - the hypothesis shouldn’t turn into a dogma). As I said, I was not trying to come up with alternatives (there seem to be enough people trying to do that here already), but was rather looking for clarification, because of my limited knowledge on the subject.

I came to conclusion that creation of mimicry of a non-static object through the means of natural selection is next to impossible (I welcome anyone to challenge that). Trees seem to be static enough. Bugs mimicking other bugs – not sure (quite possible, cause some organisms may not change their qualities for millions of years if they are not challenged by surrounding environment, thus turning them into somewhat static objects for the other organisms to mimic). I’ll probably eventually toss a couple of example into entomology forum (if I find any)….
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Postby JackBean » Fri Dec 16, 2011 3:36 pm

so what isn't static object for you?
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.
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Re: Camouflage in nature

Postby Nick7 » Fri Dec 16, 2011 11:38 pm

JackBean.... Say I have 10 hypothetical bugs. 9 of them are poisonous and 1 of them is not poisonous but mimics a bunch of characteristics (colors, patterns, shape, behavior, etc…) of 1 of the 9 poisonous bugs (a wasp, for example) for its protection. How the development of these features can be modeled?

I guess that mutations of our bug can be simulated by some random number generator. Say a random # generator produces an identical bright color spot of a bug # 2. Our bug will derive no advantage out of this element, since it doesn’t really replicate anything without other features of a bug # 2 present. Say a random # generator produces an identical buzz produced by the wings of a bug # 6. Since the sound indeed somewhat mimics the sound of a poisonous bug # 6, it increases the probability of our bug’s survival by 0.001%. Since survivability increase of this small magnitude is not substantial, the bug gets eaten before it manages to pass on its genes. Say a random # generator produces an identical threatening posture of a bug # 5 (a wasp), which increases the probability of our bug’s survival by 0.05%. The bug survives, and the feature sticks. Now the bug can capitalize on the established “relationship” unless a chance offers better alternatives. The more features of a wasp are produced, the more "dependency" arises (other, non-wasp related, randomly produced features will offer lesser value alternatives). Again, now the bug “has to” come up with a pretty substantial # of features from a countless number of random options to reach a state of a perfect camouflage (I’m not gonna count them, the examples observed in nature are pretty impressive – that’s one more link http://www.telegraph.co.uk/earth/earthp ... -seek.html ).

If we want to explain the level of results achieved in the photos provided and If the wasp itself is chasing its own evolutionary goals (hypothetically…changing with the same pace), wouldn’t we have to run 2 groups of a big amount of random numbers generators (1- st group for a wasp, 2-nd group for a bug mimicking outcomes of a group # 1) waiting for all of them to overlap with their results at a certain point of time? If we are talking about unlocking gradualistic lock here, don’t the previously unlocked combinations get reshuffled before we achieve a state of a perfect camouflage? Keeping in mind the road will be punctuated by a number of failures mentioned above (minor improvements may not immediately stick, since they offer minor advantages, etc.)

Everything I’ve said is not an attempt to make a statement, but a lack of understanding of how random mutation can produce a mirror image of a “moving” object. Again, I don’t mean that a particular object represents a particular goal, but if I observe a perfect level of mimicry today, I assume that after a certain level of accumulated qualities of a specific benchmark bug, a mimicking bug’s deviation to the right / left will only reduce the value. So the reinforcing the specific camouflage will be the most optimum way left, isn't it?
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