Now it's 2010 and we're done with the ohs, or the oughts, or whatever you want to call them. I'm fine with that. They were okay, the double-ohs, but there are better things on the horizon. I'm going to back school. I'm dancing more. I'm visiting Ireland. It's my birthday, and the sun is actually shining, having briefly broken though from whatever alternate dimension it visits during Chicago winter. So take that, universe. You have NOTHING on me today.
Now, back in September, I promised a follow-up post to the Origin of Species debacle. You'll recall the salient points - the creationist duo Kirk Cameron and Ray Comfort were planning to release an anniversary edition of Darwin's famous manuscript, complete with a Comfort-penned introduction which attempts to refute the theory of evolution. I know, it doesn't make a whole lot of sense. However, in the invening time, a number of people have done admirable jobs of pointing out the ignorance, intelluctual laziness, and plagiarism in the introduction, so I won't be refuting the whole thing here. Instead, I'll use the rest of this post to clear up a few misconceptions about evolution. It is a counter-intuitive theory, which helps to explain some of the widespread resistance to it in American culture.
Misconception #1: Evolution is a process of mindless chance which produces complexity.
This is an objection I see raised all the time by critics of evolution, and that's unfortunate, because it's one of the most easily understood concepts in the theory. It is beyond my understanding how Ray Comfort can fail to get this. The key to dissolving this misconception lies in a simple statement: Evolution contains both random and non-random elements, and those elements work together to produce complexity. Or as Richard Dawkins puts it, "Life results from the non-random survival of randomly varying replicators."
The 'replicators' Dawkins refers to are organisms, or more specifically their genes. Genes are the things that make us what we are. They tell certain cells to become an arm, certain cells to become a liver, etc. Genes can change randomly through mutation. When DNA (the code in which genes are written) replicates, errors can occur. Certain genes (or parts of genes) may be deleted, cloned, or rearranged. These random changes (mutations) provide the raw material of evolution. But now we come to the important part: non-random survival. Our genetic code is not allowed to mutate at random and go its merry little way. Instead, deleterious (bad) mutations are culled from the population because the organisms that harbor them are less successful at reproducing. Nature, having no conscious plan, is selecting for survival those organisms better able to operate and reproduce within their environment. Hence, natural selection.
Misconception #2: "There are no transitional species!" or "We still haven't found the missing link."
Many creationists harp on this phrase to such an extent that it takes on an air of "the creationist doth protest too much", but I think this particular objection raises certain important points about how we think about history and classification. Here are the important points to conceptualize:
First, fossilization is difficult. Only certain parts of animals fossilize, and only under certain conditions. We find many more fossils of sea-dwelling creatures than we do of land-dwelling creatures, for precisely that reason. Also, searching for fossils is expensive and time consuming, and rarely yields the whole-skeleton fossil that is so hoped for.
However, given the difficulty of fossilization, we do have many examples of transitional fossils. Tiktaalik was a lobe-finned fish, but had certain features in common with four-legged animals. Archaeopteryx was a feathered dinosaur extremely important in helping us understand the origin of birds. (Birds, as it happens, are all descended from the dinosaurs.)
When people talk about the 'missing link', they are really talking about wanting to find a transitional fossil that is a direct ancestor of modern humans. Despite the fact that we have found many of these, people have a tendency to see modern humans as somehow special, or different. This is a reflection of our anthropocentric nature and our failure to see our true place among a long line of transitional species.
I think that's enough for now. I'm taking a biology course this semster, so I'm sure I'll have more to share once that gets started. For now, good night and good luck.
