Sunday, January 4, 2009

What good is half a bike?

Kudos to Panda's Thumb and Carl Zimmer for bringing the pwn.

Casey Luskin, one of DI's last remaining Quixotesque crusaders for Creationism Truth, embarrassed himself recently with yet another botched analogy for Goddidit:
“Bicycles have two wheels. Unicycles, having only one wheel, are missing an obvious component found on bicycles. Does this imply that you can remove one wheel from a bicycle and it will still function? Of course not. Try removing a wheel from a bike and you’ll quickly see that it requires two wheels to function. The fact that a unicycle lacks certain components of a bicycle does not mean that the bicycle is therefore not irreducibly complex.”
Actually, bicycles can and do still function after a wheel is removed. It's called a unicycle.

This comes of the heels of a long line of botched analogies, most notably Behe's insistence that the bacterial flagellum is irreducibly complex, just like a mouse trap.

Actually, it turns out that if you take away most of the parts of the flagellum it's still functional as a type 3 secretory system.

And if you're really want to blow ID out of the water, you can get E. coli to evolve novel flagella. Guess a designer isn't really so necessary, after all.

Even the infamous mousetrap analogy itself fails miserably:

And if you look at the evolution "debate" closely, it's interesting to observe the rank-and-file creationists talking about evolution as if it were merely the addition of new, fully-formed parts, and that if you rewind the clock, you get organisms without the vital tools needed for survival. After all, what use is half a wing or half an eye or half a flagellum? That's essentially the argument of the Discovery Institute's argument, rebranded creationist arguments from ignorance.

It's hard to comment on exactly how wrong this line of reasoning is. It's like arguing with someone who seriously thinks that the Spore creature creator is how evolution actually works - that organisms are simply bestowed new parts as they go along and presto changeo, your eyeless fish suddenly has complex eyes. Similarly, with a wave of his magic wand, the Christian God Intelligent Designer has given previously-immobile bacteria the gift of the bacterial flagellum. Magic sure is neat!

But that's not really how evolution works at all. New features do come into fruition on occasion, but not out of thin air. And parts used for one function can find a new function (case in point: hands) The key concept in evolution is variation: finch beaks with slightly different lengths, primate skulls with slightly different dimensions, etc. A nearly endless variety of forms off just a few basic parts. That's how evolution really works.

And try as they might, creationists can't explain the diversity of life with magic. It simply fails as a science.

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