Why do caterpillars metamorphose?

[motorollin]

Well regardless of why it happened, here is what emerged from the cocoon created by the caterpillar I caught. I have released her in to the garden now, so she is free to lay useless unfertilised eggs, and lie helplessly as predators consume her wingless body. Ahhh, the beauty of nature.

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moto

[FluffyMcDeath]

Caterpillars metamorphose to reproduce. Caterpillars do the eating and growing big from a tiny egg part of the life cycle, the butterfly does the breeding and egg laying.

It's a very common mode in nature, especially among insects. Think maggots and flies, etc.

Egg, larva, nymph, pupa, adult. Sometimes skipping one or some.

See Wiki

And here is the pretty Ladybird

[motorollin]

I understand the functions of each stage in development and what part they play in the animal's life cycle. My question was more focussed on why this complex lifecycle evolved, rather than the larval form becoming extinct in favour of the better adapted adult form. I now know that this is because the eggs laid by the adults are too small for a smaller version of the adult creature, which is why the tiny larvae hatch and then grow.

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moto

[bloodline]

motorollin wrote:
Is it usual for moths/butterflies/insects to lay eggs whether they are fertilised or not?

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moto

If a fly doesn't lay it's eggs, they will hatch out inside the female and consume her.

Read Richard Dawkins, "Selfish Gene" for more info.

[motorollin]

bloodline wrote:
If a fly doesn't lay it's eggs, they will hatch out inside the female and consume her.

Fascinating, but still,

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moto

[CannonFodder]

bloodline wrote:

motorollin wrote:
Is it usual for moths/butterflies/insects to lay eggs whether they are fertilised or not?

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moto

If a fly doesn't lay it's eggs, they will hatch out inside the female and consume her.

Read Richard Dawkins, "Selfish Gene" for more info.

Slightly OT here:  I just read Richard Dawkins "The God Delusion" it was very entertaining.  He's kind of a cross between Milli-Tant from Viz and Osama bin Laden, with a bit of Atheist2 thrown in for good measure. :-)

[bloodline]

CannonFodder wrote:

bloodline wrote:

motorollin wrote:
Is it usual for moths/butterflies/insects to lay eggs whether they are fertilised or not?

--
moto

If a fly doesn't lay it's eggs, they will hatch out inside the female and consume her.

Read Richard Dawkins, "Selfish Gene" for more info.

Slightly OT here:  I just read Richard Dawkins "The God Delusion" it was very entertaining.  He's kind of a cross between Milli-Tant from Viz and Osama bin Laden, with a bit of Atheist2 thrown in for good measure. :-)

Yeah, the first few chapters are a bit "ranty" (which I found off putting, surprising given how much I have enjoyed all his previous books)... but once he gets stuck into the science, the book is really good! His best work by far is the "Extended Phenotype" though...

[bloodline]

motorollin wrote:

bloodline wrote:
If a fly doesn't lay it's eggs, they will hatch out inside the female and consume her.

Fascinating, but still,

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moto

The point I was making, is that the fly/insect/individual is irrelavant, all that matters is that the genes are passed on.

[motorollin]

I understand that. I genuinely was fascinated by that, it was not a facetious comment :-)

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moto

[bloodline]

motorollin wrote:
I understand that. I genuinely was fascinated by that, it was not a facetious comment :-)

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moto

No, I know! I'm excited by your thirst for knowledge, I felt it important to make that point. Please do read the "Selfish Gene"!

[motorollin]

bloodline wrote:
No, I know! I'm excited by your thirst for knowledge, I felt it important to make that point. Please do read the "Selfish Gene"!

Just ordered from Amazon :-) I read the first few pages of the introduction and it sounded right up my street.

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moto

[motorollin]

Intriguing...

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moto

[bloodline]

motorollin wrote:
Intriguing...

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moto

As I understand it, this isn't possible... I'll have to read up some more...

[Speelgoedmannetje]

motorollin wrote:
Intriguing...

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moto

That 'soup' comment made me think the catterpillar is an evoluted egg. (as these animals spawn as much eggs as possible, those eggs with the most capabilities can survive).

[bloodline]

Speelgoedmannetje wrote:

motorollin wrote:
Intriguing...

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moto

That 'soup' comment made me think the catterpillar is an evoluted egg. (as these animals spawn as much eggs as possible, those eggs with the most capabilities can survive).

Inside a caterpillar there is a small bunch of cells that perform no function. Once the caterpillar has reached the desired size and spun itself into a protective cocoon, this small bunch of cells secrete a digestive enzyme that turns the catapiller into a nutrient protein soup... the cells then feed on the soup and grow into the butterfly.

That is the currently accepted method of operation. This research suggests this may not be the case. Since the currently understood mechanism treats each stage of the life cycle as independent organisms, no learned behaviour could be transferred.

[Karlos]

It strikes me that it ought to be obvious that not all of the organism is broken down into nutrient, no matter how much digestive juices are released. Some component must remain intact. If it were not the case, surely there'd be nothing left to grow into the adult form :-?