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Design in Butterflies

Posted: Wed Mar 07, 2012 1:10 pm
by Stu
So this post lead to me being banned from another site, so I hope that isn't the case here :esad: :)
I would definitely recommend Metamorphosis to anyone ho hasn't seen it. Great documentary.

Found a fascinating article (which in fact provides commentary on a new film Metamorphosis) relating to design in Monarch Butterflies.

What do we associate within designed systems. Forward planning, integrated sub-systems, a blueprint and at times multiple blueprints for complex integrated systems.
Whereas Darwinian evolution acts in the moment, selecting for whatever works best in the present. No planning for tomorrow, no forsight to judge what might prove useful down the road; in other words there is no front-loading.

With that in mind let's consider just what the transformation from caterpillar to butterfly entails:

- First the caterpillar spins a silk button from which it hangs, forming a chrysalis;
- within the chrysalis the entire body of the caterpillar is subsequently dissolved into a tissue soup;
- this raw material is then in turn recycled into an entirely novel organism, the butterfly, composed of a fundamentally distinct body plan from that of the caterpillar


On a sidenote regarding an organism's body plan:

*** Scientists still don't know where the body plan for any organism, plant or lifeform is located, or how it forms. It's thought to reside somewhere in the 3D structure of the cell (formed upon sperm/egg fertilisation), but exactly where we don't know. It's not believed to reside within DNA.
This provides another obstacle for the evolutionary formation of the butterfly -- as a simple mutation to the structure / sequence of DNA would be ineffective in creating novel lifeforms, as the (overriding) blueprint or body plan would remain intact (as opposed to subtle variations within a species).

This is borne out within the actual DNA content of cells in differing regions within an organisms body. For example the prospective head region of an organism contains the same DNA as cells in the prospective tail region. Yet head cells must turn on different genes from tail cells, and they "know" exactly which genes to turn on, thus from outside of DNA. Therefore a key part of the ontogenetic cycle (stages from fertilised egg to adult) cannot be located in the organism’s DNA.

This goes some way to answering why most mutations are either harmful or deleterious -- biologiocal lifeforms are essentially "closed systems", functioning within specific parameters (body plans) that cannot be altered wholesale through mutations to the DNA structure / sequence alone. As large scale mutations would conflict with the overriding body plan and more than likely "shutdown"; hence why we only ever see micro-evolutionary changes -- small-scale change is the only alteration to DNA structure tolerable without rendering it incompatible with the principal body plan.

This is revealed in studies like Richard Lenski's 20-year (50,000 generation) E. coli experiment (that equates to 1 million years of human evolution). ***


Here are the hurdles that neo-Darwinain evolution cannot overcome.
1. Two entirely distinct body plans (the latter, or butterfly, being far more complex than the first).
2. A selective advantage for committing suicide.

If evolution is a step by step process of mutation and selection, building the body plan as it proceeds along an evolutionary pathway:
- how and where does the second body plan arise?
- and for what possible reason would natural selection pick a pathway leading to the destruction of the organism?

On the other hand all intelligent agents (you and I included) are familiar with this concept; it's known as front-loading.
Ensuring processes, plans and systems are in place prior to their being required to execute a specific function.

For example, one could design a commercial aircraft with one engine, as it would still fly; but an intelligent agent recognises that if that single engine fails, the aircraft will crash. Hence twin-engines. Same would apply to an off-road vehicle capable of submersion within water. The engine is designed not only for traveling on roads, but ensures the vehicle would be capable of overcoming an obstacle such as crossing a river.
Of course these are fairly crude examples when compared to the caterpillars transformation. A more accurate description would be that of a 1950's Beetle entering a garage, being stripped and broken down; and emerging out the other end as a self-assembled sleak private jet; though still no where near the complexity of a butterfly.

How does neo-Darwinian evolution construct an additional finely-tuned, unique (flight) body plan when all it's resources have been directed toward ensuring the survival of the caterpillar through mutation to DNA.
And why would it select for a path that essentially kills the animal, rendering reproduction impossible, without having that pre-determined plan to reorganise said deconstruction into a second fully-functioning (flying) organism.


Here's a short trailer of the film itself:
Metamorphosis: The Beauty & Design of Butterflies

Re: Design in Butterflies

Posted: Wed Mar 07, 2012 2:38 pm
by jlay
Yes, this gets right back to the issue of 'function' I mentioned on the other thread.

I would like to hear how Darwinism accounts for the function that includes the cacoon phase.