The Ant and the Blade of Grass

[bunny]

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When the first spider froze at the sight of a predator, it presumably survied because of this. Since this is NOT a random mutation, I don't get how it is first got passed down and evolves. Unlike the the physical characteristic of spots, I don't see how a behavioral characteristic such as freezing is passed down for the firs time. Freezing seems to be a "learned" behavior. I understand how a wildebeast teaches its offspring to freeze at the sight of a lion, and I can even see how this might eventually become hard wired into future generations of wildebeasts. But insects don't possess the intellect to learn from watched behavior of parents (at least I didn't think so).

So exactly how does behavior in insects evolve?

I'm STILL not asking the question the way I want, but hopefully this is close enough.

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I think the bolded part is your error - presumably the "freezing" is the manifestation of some hormonal (or equivalent if spiders dont have hormones) event in the spider's brain (or equivalent, again). Why should this be any less likely to occur than a random change to a beetle's coloration?

I dont see that you're justified to conclude it is a learned behaviour rather than an instinct.

EDIT: Similar to luckyme's motionless amoeba - very primitive animals could accidentally develop a whole host of instincts like that. The later generations who have a developed enough brain to learn would more be adding to their inherited instincts, rather than supplanting them. Most animals are born able to walk - we have to learn. If there can be an instinct for walking, why not for staying still when you sense movement?

[NotReady]

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You know enough to cringe when you hear agency bestowed upon mindless processes (mindless added for NRs benefit)


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I don't cringe when anthropomorphism dominates evolutionist literature. I love it. I especially love the way mindless evolution designs complicated mechanisms when the genius of man can't even understand how. Chance beats purpose every time.

[Phil153]

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You know enough to cringe when you hear agency bestowed upon mindless processes (mindless added for NRs benefit)


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I don't cringe when anthropomorphism dominates evolutionist literature. I love it. I especially love the way mindless evolution designs complicated mechanisms when the genius of man can't even understand how. Chance beats purpose every time.

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If you understood it, you might discover that the world is actually more wondrous, not less, without the petty homosexual slayer and child drowner interpretation that you put on God.

Evolution doesn't design anything. A trillion trillion trillion trials parallel trials performed over billions of years will gradually select for the fittest in ways incomprehensible to the human mind. You really do your God a disservice - his majesty is far greater as a creator and nurturer of a vast cosmic experiment than as homoslayer, the creator of Super Special NotReady on his Super Special Earth. Do you see why?

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As for the OP - I'm not sure why insect freezing is so amazing. They do have brains and nerves centers. The ant story is quite interesting - there are probably simple triggers. It reminds me of toxoplasmosis which causes mice to lose their fear of cats and seek out cat urine, which is advantageous to the parasite breeding cycle. They infect human brains too - a scary read. I guess homoslayer thought that was a good idea?

[MidGe]

As was told by an earlier poster on this thread, of course, the worms that accidentally develops the right chemical to make the ant climb a blade of grass is definitely gaining a evolutionary advantage. You only, in fact, need one such an accident and a high reproduction rate and you are home, Jose!

Of course, it may be even better if it only succeed in senile ants or ants that have no reproduction capabilities.


I mean, I feel sorry, for the ant, but that seems to exemplify once more the sadistic leanings of the designer of nature. Of course, rather than imputing such a malignant designer, I feel much happier and comfortable attributing it just to a chance/random event.

[hexag1]

Lestat,

You have to understand that the behavior that the freezing behavior
that an insect or spider exhibits doesn't just occur to it in midlife.
Its hardwired into it. Some spider, the child of spiders that didn't freeze,
was born with a mutation that caused it to behave this way. It survived,
and its kids were better at surviving, and now its DNA has taken over the
spider population.

Actually thats probably not even true. More likely this behavior evolved millions of
years before spiders evolved on land. Spiders are descendents of critters that lived
in the ocean 500+ million years ago. About 543 million yeas ago, during the Cambrian
explosion, the first creatures with proper vision evolved. These were probably primitive
trilobytes. These creatures, and their descendants are the ancestors of vertebrates
and of arthropods, of which spiders are a part. During this time, early arthropods
developed vision. This new development caused creatures to evolve evasive behaviors
like the ones youve seen in spiders. For more on this, see Andrew Parker's
book "In The Blink of an Eye".

Perhaps spiders do have some ability to rewire their brains and learn like a
mouse can. But it doesnt have to learn this behavior at all. Most, if not all,
of it's behavior is dictated by its genes. The layout of its brain and and the
connections of the neurons that control its muscles is probably all laid out
by its DNA. The spider's brain probably doesnt get rewired the way a mouse's does.
Natural selection hasn't given it this ability because it has no need of it.
Spiders live in fairly static environments, and they tend to spend their lives in
one spot, so they can live and reproduce with a limited set of behaviors.

[hexag1]

The fluke worm is a tougher puzzle. The difficulty is twofold. The first question is
did the lancet fluke invade the ant first and then move on to invading the cow?
Or was it alread invading the cow before natural selection stumbled upon the fast track
to the cow's body through the ant? I dont know enough about the situation to know which,
but considering how many other worms and stuff infect cows intestines, I would hazard that
it was infecting cows first.

If we assume that the fluke first infected cows, then the second question is: how did the
worm take over the ants brain? Natural selection cannot have just stumbled upon the answer
on the first try. It had to have been infecting the ant or otherwise been riding along
with the ant profitably before evolving the ability to change the ants behavior. What was this
advantage? I dont know the answer, but my guess is that some expert can find a related fluke, midway
through the same evolutionary pathway that our worm did, and infecting the ant without affecting its
behavior.

[NotReady]

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without the petty homosexual slayer and child drowner interpretation that you put on God.


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You're a big fat ignorant jerk - so there.

[Phil153]

Hey, you claim the bible has never been shown to be false, so these things MUST be true. They're in the book you choose to believe. You can't have it both ways.

Sorry for the off topic rant, interesting thread.

[GoRedBirds]

Don't apologize, Phil. Your first post in this thread was spot on. I am always in awe of the amazing diversity on the branches of the evolutionary tree. The worm in the OP is a great example of the myriad ways life finds to continue. And FWIW, I went after a spider the other day and that bastard was quick. Evidently, he was hardwired for speed.

[luckyme]

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When the first spider froze at the sight of a predator, it presumably survied because of this. Since this is NOT a random mutation, I don't get how it is first got passed down and evolves. Unlike the the physical characteristic of spots, I don't see how a behavioral characteristic such as freezing is passed down for the firs time. Freezing seems to be a "learned" behavior.

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thanks for clarifying.

One problem point seems to be your affinity for brain. By similar reasoning, sunflowers can't turn to the sun. 'we can understand them being yellow, but how do they KNOW to turn at the right time? After all, it occurs in midlife and the seed didn't so it must be a learned behavior.'

Even if there were a 'first spider to freeze', ( which I very much doubt, danger avoidance is ubiquitous) surely there would be something in it's system that caused it and therefore the survival improvement would be the result of a random mutation.

The learning you mention occurs at the evolutionary level not at individual spider level. It's the spiders genetic code that 'learns' but yet it doesn't 'know' it in the sense you're using it, it learns it and knows it the same way it knows to be speckled.

luckyme