We've known for a long time that the most common mistake is assuming that there's only one solution to a problem. They see an end result, like a bacterial flagellum, or resistance to malaria, or the binding of two proteins, and assume that a few very specific mutations had to occur in a specific sequence in order to produce that result.
judmarc calls this the "lottery fallacy" and I think it's a good term [see lottery fallacy],
This is of course what I like to call the "lottery fallacy." It's used by virtually every ID proponent to produce erroneously inflated probabilities against evolution.As it turns out, someone on Evolution News & Views (sic) just posted an excellent example of this fallacy [Intelligent Design on Target]. Here's what he/she/it says,
Lottery fallacy: The odds against any *particular individual* winning the PowerBall lottery are ~175 million to 1. But there were three winners just last night. That's because *someone* winning the PowerBall is not an especially rare occurrence. It happens every few weeks throughout the year.
In exactly the same way, Axe, Gauger, Behe, and the rest of the ID folks always base their math on the chances that a *particular* neutral or beneficial mutation will occur, and just as with the lottery, the chances of a *particular* outcome are utterly minuscule. The occurrence of *some* neutral or beneficial mutation, however, is, as with the lottery, so relatively common as to be completely unremarkable.
To summarize: ID proponents misuse probability math to make the common appear impossible.
In his second major treatise on design theory, No Free Lunch: Why Specified Complexity Cannot Be Purchased without Intelligence, William Dembski discusses searches and targets. One of his main points is that the ability to reach a target in a vast space of possibilities is an indicator of design. A sufficiently complex target that satisfies an independent specification, he argues, creates a pattern that, when observed, satisfies the Design Filter. There are rigorous mathematical and logical proofs of this concept in the book, but at one point, he uses an illustration even a child can understand.The unknown author included the image shown above in order to illustrate the point (Image: © Kagenmi / Dollar Photo Club).
Consider the case of an archer. Suppose an archer stands fifty meters from a large wall with a bow and arrow in hand. The wall, let us say, is sufficiently large that the archer cannot help but hit it. Now suppose each time the archer shoots an arrow at the wall, the archer paints a target around the arrow so that the arrow sits squarely in the bull's-eye. What can be concluded from this scenario? Absolutely nothing about the archer's ability as an archer. Yes, a pattern is being matched; but it is a pattern fixed only after the arrow has been shot. The pattern is thus purely ad hoc. [No Free Lunch, pp. 9-10, emphasis added.]Most people have experience with target shooting of some kind, whether with bows and arrows, guns (including squirt guns), snowballs, darts, or most sports like baseball, soccer, basketball, hockey, and football. Children laugh when they picture an archer who "couldn't even hit the broadside of a barn" and rushes up to the arrow and paints a bull's-eye around it. Grown-ups might compare that to a biologist looking at an irreducibly complex biological system and simply stating, "It evolved." In each of these cases, Dembski would say that since the pattern was not independently specified, therefore it is ad hoc.
Do you see the fallacy? Just because we observe a complex adaptation or structure does NOT mean that it was specified or pre-ordained. There are certainly many different structures that could have evolved—most of them we never see because they didn't happen. And when a particular result is observed it doesn't mean that there was only one pathway (target) to producing that structure.
To continue the analogy—at the risk of abusing it—there may be hundreds of targets in the woods and most of them have very large bullseyes. Imagine you're out for a walk in the woods and you see that almost every tree has a big target with a large bullseye. You find an arrow stuck at the edge of one of the bullseyes and lots of arrows stuck in the trees, the ground, and parts of most of the targets outside of the central bullseyes. Would you write a book about how good the archer must have been?