Why Doesn’t Natural Selection Make Sense for the Origin of Life?
Dr. Stephen Meyer: If you make some simple calculations about the number of possible ways there are of combining the amino acids in a protein, or the information carrying bases in a DNA molecule, and then you compare that to the number of events that have taken place since the big bang, where an event is a minimal interaction of an elementary particle, it turns out that the number of combinations searched is far in excess of the number of events that have taken place since the big bang. So you’re essentially in the situation like a blindfolded man looking for a needle in a haystack, except the haystack is something the size of the universe, and you’ve got a very limited time to search that. It just isn’t going to happen, and that’s why the scientists have really dismissed the chance hypothesis as not being credible. So the next approach has been to some to somehow combine chance with natural selection. But the big problem there is that natural selection is only a force to be reckoned with once you have life that can reproduce, produce offspring, create competition among the offspring for survival. And… in other words,…if you want to explain the first life, you can’t invoke a process that presupposes the existence of life. And natural selections does that. So here’s an illustration I have that gets across the logical problem here. There’s an absent-minded philosophy of science professor. And he’s walking home from his office. And he’s thinking great thoughts. Maybe thoughts about… who knows, maybe DNA. And he isn’t paying attention to where he’s going. He’s already lost his cell phone, his keys, … and now he falls in a pit. It’s a deep pit, 30 feet deep. He’s lucky to have survived. But he … he dusts himself off and he says, “Well, no problem. I’ll just go home and get a ladder, and climb… and then I’ll come back and then I’ll climb out of the pit. All I need is the ladder.” so he gets out of the pit. Goes home, gets the ladder, comes back, jumps in the pit. And then climbs out. Now, obviously there’s something wrong with my story, and that is that it’s begging the question as to how the absent-minded professor got out of the pit in the first place.
And that’s essentially what’s going on with these proposals of prebiotic natural selection. they’re begging the question of the origin of DNA and proteins which is necessary to get natural selection even going. What were we trying to explain? The origin of DNA and proteins, and yet you’ve invoked a process that presupposes the very existence of the thing you’re trying to explain in the first place. So that approach has been seen as kind of a non-starter, a dead end.