Sunday, August 30, 2009

So, What's the Problem?

All too often, if I have an extended encounter with a Creationist, I find they'll apparently agree with all the premises of evolution, but never point out where they disagree with it. C0nc0rdance made a video on that point:

For the sake of saving time and clicks, here's the list he uses:
1. DNA is the basis of heredity.
2. DNA changes over generations.
3. DNA is responsible for the differences between organisms.
4. The environment acts on the frequency of changes.
5. There is no physical limit to the amount of changes that can occur in DNA.

The video does a great job, though I feel I should put in a little commentary of my own.

Point 1: Heredity: I haven't met a Creationist who disputes this, yet. I am aware of a passage about goats and striped poles that gives them room for it, though.

Point 2: Changes over generations: Another that you would think is indisputable. I have, however, seen a few Creationists who've painted themselves into a corner where they would have to argue that offspring are clones of the parent(s) to avoid self-contradiction. No, it didn't dawn on them.

Point 3: Differences between organisms: Minor nitpick referencing developmental errors that lead to so-called "science journalists" to label critters with extra bits as "mutants." If these malformed critters do manage to reproduce, however, their offspring will more than likely be normal. Of course, there are other environmental causes of difference, but it's perfectly okay to skip over them for the sake of brevity. DNA's the big, big one for discussions of evolution, and my nitpickery is only worthy of being shoved into a footnote.

Point 4: Environment acts on frequency of changes: I think this could be rephrased for greater clarity. He goes into greater detail in the video, but the slogan-sized snippet shouldn't require a followup elaboration to get the central points across. It should be a quick summary behind the idea behind natural selection, genetic drift, and the founder effect. I'd like to hear suggestions.

Point 5: No physical limit: The most common point of dispute I've been able to nail Creationists down to, and probably worth a whole video or blog post by itself. There are some limits in the form of development-related genes: They're highly conserved because changes to those part tend to kill the offspring before it leaves the womb/egg/seed. That's why you won't find big changes to body plans, like sprouting additional limbs (said developmental errors, of course, don't count) that could turn into wings. And of course, if too many changes happen in one offspring, it could render it infertile in regards to the rest of its parent species. Thankfully, evolution never posits such absurdities, no matter how much Creationists wish it did.

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