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There are probably countless examples of evolution that might lead us to conclude that there was some "intelligent" driving force at work. However, consider that you might be comparing the time scales of evolution processes with time scales of processes that you are familiar with.Evolution is slow and very subtle. It tends to operate over time periods that we may find difficult to relate to.
What's the half-way house for metamorphosis?
I understand that evolution is very slow, but metamorphosis does not seem to relate to the small incremental steps that we normally consider when discussing evolution. There are many biological changes that occur during metamorphosis that do not seem possible under our normal understanding of evolution: many of these changes would result in the necessary death of the insect prior to to the next evolutionary step.
There is also newbielink:http://en.wikipedia.org/wiki/Atavism [nonactive] to consider which can cause an (ancient) feature appear fully formed, out of the blue : rather than by incremental changes, (although the feature may have first formed by incremental change), e.g. newbielink:http://www.anatomyatlases.org/AnatomicVariants/SkeletalSystem/Images/19.shtml [nonactive].The caterpillar could have had a life cycle which did not involve changing into a butterfly,but it carried ancestral dna of a insect born with wings, which made an atavistic reappearance producing the metamorphosis into a butterfly, i.e. the caterpillar may not have developed wings incrementally, it may have got them all at once, fully formed, via atavism.
Evolution is a slow process, so metamorphosis would have evolved slowly. The first insects would have had no metamorphosis, then later partial metamorphosis would have evolved, then full metamorphosis. Modern insects show all three levels, which is evidence that it did evolve. There is considerable advantage in metamorphosis. Adults and young are able to use a different food sources and habitats so they are not in competition, so there could have been plenty of evolutionary pressure to evolve metamorphosis. I don't see why metamorphosis had to be lethal at any point.If you cannot explain how it evolved it merely demonstrates your lack of imagination, not the impossibility of it evolving!
A concern that I have is that if we blindly accept our present theory of evolution because it seems to fit 99% of the changes that we have seen over biological evolution, we may ignore the other 1% that we have no explanatiuon for, and thus the possibility of adding to or modifying the theory.