I've been asked why I don't accept peppered moths or finch beaks as evidence for Darwinian mechanisms.
There are quite a few reasons for the finches. Maybe I'll talk about the moths some other time.
First, though, I'd like to note that talk.origins (an oft-referred-to resource for Darwinism online) discusses the finches, so let's look at some representative quotes:
A) Darwin's Finches remain one of the best examples of adaptive radiation in the literature of evolutionary biology.
Let's see how much they beg the question. This admission is pretty funny to me.
The evidence better be impressive, since there's all this overwhelming evidence, as we all know.
B) the Galapagos finches were a new group strictly confined to the Galapagos
For this to be worth any explanatory power, it would have to assume that the finches diverged from a different population at some point in history. What's the argument for that, I wonder?
C) if the droughts had continued, say one every ten years, then a trend of increased beak size due to selection would be predicted.That's a big "if".
And you don't know where the beaks were originally or what the finches looked like beforehand.
D) The climate of the Galapagos has not remained stable over the last 50,000 years.
Geological strata and such can only tell you so much about weather patterns.
Again, you don't know where the finches started.
What about before that?
If it wasn't stable, why wouldn't we think that there would be an effect that swings back and forth but usually tends to return back to the equilibrium?
E) We can see from this, coupled with what we know about how fast selection can influence beak size, that there was more than enough time for significant directional change to occur.This is a huge assumption - the Darwinian modus operandi. I love it.
For one thing, I'm pretty sure that not all Darwinians agree that such would be nearly enough time.
The big assumption is that more than beak size would be affected over a greater amount of time, that the finches with huge or tiny beaks would eventually evolve into, I don't know, a mammal or something. But the argument for how that occur and the evidence that it HAS occurred is sorely lacking. What we have here is a change in BEAK SIZE.
F) Are species defined "strictly by inability to interbreed"? Not by any species concept commonly used today.But there is no one agreed-upon definition of "species", so I don't see what the objection to what the ID scientist said could be.
Now, for a few what I would call admissions in the article:
-In fact, the climate seems to oscillate between drought and plenty of rain, creating a kind of equilibrium.
-(Jonathan Wells, an ID proponent) also notes: "Some sort of long-term trend would have to be superimposed on the back-and-forth oscillations to produce long-term change."
(exactly my point)
So in the final analysis, the finches are pitifully bad examples of Darwinian mechanisms because:
1) Variations in the beak sizes over time were observed. Bigger to smaller to bigger to smaller.
2) The finches are still FINCHES. The evidence for which I'm asking would be more along the lines of "We have evidence that amoebae evolved into finches" or "We have evidence that finches evolved into rodents" or whatever silly thing birds are supposed to be evolving into these days. I don't see why assuming that these changes might lead to a different kind of animal in the future is warranted, especially since no such thing has ever been observed. I'm just trying to keep science pure science here, people.
3) I wonder where evidence for these miraculous and essential (and virtually non-existent) naturally-occurring beneficial mutations that will cause the big jump into non-finch-hood is?
4) Hybrid "species" occur in the wild as well.
5) All of the facts that talk.origins or anyone else I've seen so far wants to count as evidence for their Darwinian position are accounted for just as well (if not better) in a Young-Earth Creation model, global flood or no global flood. I'm looking for something that would shoot down a YEC model in favor of, for example, Darwinian ideas, not something that's shaky in a Darwinian framework and easily explainable in a creationist framework. I think you've got it backwards there.
"Yeah, that's right, ya stupid fundie! Goddidit!!!"
Perhaps you could make an argument for why "naturalisticDarwinianmechanismsdidit!!!" is a better answer.