Some Thoughts on Evolution

Evolution is kind of a weird third party to the whole religion/atheism thing. One can be a theist and still “believe in” evolution. One can be an atheist and still think that evolution doesn’t pass muster.

So what does evolution mean? I think a lot of people are muddled.

My understanding is that evolution means “change over time”. When we say that a species has evolved, it means that species, as a whole, is different than it used to be at some point in the past.

This should be so flatly obvious that I have a hard time imagining anyone would disagree with it. This is the basis for the selective breeding that we’ve done on farm animals, thoroughbred horses, orchids, and show dogs for centuries. If you want to change the shape of the nose of a particular breed of dog, you simply mate pairs that have the noses you like, and pick the puppies from the litter that are closest to what you want. Then mate them with others. After a few generations, you’ll have a dog with different shaped nose.

But people who don’t accept evolution seem to miss some fundamental point. They say “Yeah, I agree with that, but I’ve never seen a dog give birth to a duck.” They say this as if they actually think that that’s what evolution would predict: that in a single generation a parent would give birth to a wholly different kind of animal.

Or they talk about transitional forms. They say “if an animal evolved from one kind to another, then we should see some hybrid mixture somewhere in the middle.” I’m not sure how they can say this with a straight face, but they do. It’s a totally fallacious challenge, because anything you ever show them, they can just respond “that’s not a transitional form… that’s just an extinct species from Creation.”

So there are two halves to the picture. In very short order, we can show that species of animals can change in just a few generations. There have been experiments with fish that have been stocked into different streams with varying degrees of predators. The fish that were put into streams with bigger fish that would eat them changed color over some generations, turning dull and brown and camouflaged. The natural variation in coloration over generations favored these kinds of fish. The fish that were put in streams with few or no predators turned more brightly colored. In this case, flashy colors helped attract mates, and that trait was selected.

Or these California salamanders.


Creationists readily accept these changes, I think. What they just can’t seem to grasp is that the accumulation of these changes over a long period of time can add up to substantial changes.

In this post, the first words were one color. Now they are another color. Can you find the exact word that is half red and half blue? Of course not. But you must admit that there has been drastic change over the course of this post.

I’m running out of steam. Hopefully this makes some sense.