Quantifying evolution. Some people have a problem with the idea of evolution from a purely scientific standpoint. It is not testable. It makes no quantitative predictions, provides no numbers that can be compared with the real world. Therefore it cannot be disproved.
This puts the theory in bad company. The witch hunters of Europe regarded anything that made them look bad as a deliberate plot of the devil. There is a book, the Malleus Maleficarum, the Witches’ Hammer, that was written by two witch hunters. They argued their case for persecuting witches and defended their own approach. Anything that made them look bad was dismissed as a devilish plot. Once in the heat of generating prose, they mentioned a legend that the tomb of Ulysses was on a cliff overlooking the sea, and that the ghosts of his men entered birds that came and flew around the tomb. Somehow this presented a problem for the inquisitors, so they blandly announced that the devil made the birds fly around the tomb so people would think that it was the ghosts of the men, which would lead people into heresy.
Not only does is seem far fetched that people could be expected to make such a leap of the imagination, nor only that the very truth of the legend was and is wide open to doubt, but birds just do that sort of thing. As a youth I once stayed in a hotel fronting the sea. The hotel had towers at each end. It was fun to watch the pelicans gliding with grace wheel in front of one tower and then turn and dive slowly to the other tower to make another rising turn riding the updraft. But instead of going to look at a building on a cliff over the sea, they wrote it off as a plot against themselves.
I am sorry to say, but Freudian psychoanalysis could be defended on the similar grounds: “The fact that you do not accept the truth is just more evidence that you have failed to grow up.” In fact, I have never heard that said in so many words, but evidence for Freud’s notions was always lacking. At least I myself have never heard of any. And the test that would have potentially disproved Freud was never announced where I heard of it.
So if evolution cannot be disproved, then it is in very bad company. There has been no evidence, real or plausible, that would lead to the conclusion: “Well I suppose evolution cannot account for that fossil, so evolution must not have happened.”
In the heyday of modern physics one illustrious physicist criticized a theory he did not like with the words, “It’s not even wrong.” If a theory is not subject to test, that shoe begins to look like it might fit.
Things have now changed. Although the calculations we present do not produce clear absolute numbers, there is a pattern that is easily recognized and is reflected in the real world. As population size rises from a very low number, fertility rises to a maximum, rapidly falls and then begins to level off. In fact we counted 16 successful predictions. There is no way to get there from the simple phrase “survival of the fittest.” But by considering genes in the largest sense, viewing the population instead of the individual and taking the long view, that is where we find ourselves.
So what is the score? Does evolution pass the test or not. You could argue either side of the question
You could say evolution passes, because my approach also assumes inheritable variation and differential survival that occurred over a long time. Thus the theory is vindicated.
On the other hand, this is science. What is true must be what most conveniently describes the world we see while still making the most accurate description possible. Newton’s theory of gravity was and remains a very useful tool for predicting what happens to bodies falling or drifting in space. When Einstein published his General Theory of Relativity, the math was more difficult, but it is accepted because it accounts for things that Newton did not account for. Whether you say Einstein disproved Newton or improved on Newton, the fact is that the new theory supersedes the old. And the description given is precise enough so that there is a very real possibility (however unlikely) that some day we shall have to say Einstein was wrong and that a new theory now holds. That is a strength of Einstein’s theory, not a weakness.
In that sense, you could maintain that I have disproved evolution. I do not make that claim, partly because in the present harsh climate I might make friends who in the end would be disappointed and enemies who should not be enemies.
Another improvement I do claim is that my theory is disprovable. In fact it is fairly easy to “disprove” the theory as I have given it on the main page. Raise the total number of possible offspring to 12, re-tweak the other parameters and you can have a population run through its cycle of takeoff to crash far faster than the roughly 80 generations in figure 5 on the main page. Since the truth is closer to 10 generations, that tweak would automatically disprove me. And given more and more computing power, it would be possible to make any number of improvements in the assumptions.
One could have a more realistic number of possible offspring. One could add more genes of the two sorts we consider. One could add different kinds of mutations including dominant deleterious mutations and occasional beneficial mutations. One could make it possible for one to mate with an individual of a different generation. In fact it would be possible to make it more realistic by assuming that one generation does not have to end before another begins, that there are multiple chromosomes with rearrangement and chromosomal changes possible, that not all sites of possible mutation have the same likelihood of mutating or the same impact (for genes tuned to each other) if a mutation does happen. One could make it possible or an individual to change mates during his or her mating cycle. One could specify some individuals as males and others as females. One could add a provision that individuals are less likely to mate with those more closely related or less closely related than in some middling range.
In short, given some interest, it might well come to pass that hardly a year goes by without a new and improved version.
That would be a good thing. It would mean that the whole issue was now not only subject to test and confirmation in many ways, but that such important work was actually being done.
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