Darwin and Biologic Change
The answer seems to be: “Mutations, yes; evolution, no.” In the last analysis, mutations really don’t help evolutionary theory at all. There are three major problems or limits (and many minor ones) that prevent scientific extrapolation from observed mutational change to hypothetical evolutionary change.
(1) Mathematical challenges. Problem number one is the mathematical. I won’t dwell on this one, because it’s written up in many books and widely acknowledged by evolutionists themselves as a serious problem for their theory.1
Fortunately, mutations are very rare—or are they? They occur on an average of perhaps once in every ten million duplications of a DNA molecule (107, a one followed by seven zeroes). That’s fairly rare. On the other hand, it’s not that rare. Our bodies contain nearly 100 trillion cells (1014). So the odds are quite good that we have a couple of cells with a mutated form of almost any gene. A test tube can hold millions of bacteria, so, again, the odds are quite good that there will be mutant forms among them.
The mathematical problem for evolution comes when you want a series of related mutations. The odds of getting two mutations that are related to one another is the product of their separate probabilities: one in 107 x 107, or 1014. That’s a one followed by 14 zeroes, 100 trillion! Any two mutations might produce no more than a fly with a wavy edge on a bent wing. That’s a long way from producing a truly new structure, and certainly a long way from changing a fly into some new kind of organism. You need more mutations for that. So, what are the odds of getting three mutations in a row? That’s one in a billion trillion (1021). Suddenly, the ocean isn’t big enough to hold enough bacteria to make it likely for you to find a bacterium with three simultaneous or sequential related mutations.
What about trying for four related mutations? One in 1028. Suddenly, the earth isn’t big enough to hold enough organisms to make that very likely, and we’re talking about only four mutations. It would take many more than that to change a fish into a philosopher, or even a fish into a frog. It was at this level (just four related mutations) that microbiologists gave up on the idea that mutations in asexual lines could explain why some bacteria are resistant to four different antibiotics at the same time. The odds against the mutation explanation were simply too great, so they began to look for another mechanism—and they found it.