Something I just thought of recently (probably–pun definitely intended–due to my re-reading of Shattering the Myths of Darwinism by Milton). It deals with the issue of probability in evolution.
I addressed part of this once upon a time in this article. However, it is time for a little refresher. To begin with, let us first get some simple understanding of how the theory of evolution is “supposed” to work.
Firstly, let us take “natural selection.” Natural selection is the process by which the fittest of a species survive to produce more offspring.  In biology, both “fittness” and “survivability” are defined as the production of offspring. Thus, natural selection is basically a tautology stating “those who produce the most offspring”–the fittest–”are those who produce the most offspring”–survive. Put in that way, natural selection loses its explanatory power.
Regardless, let us assume that it is a valid point. What is important to note is that natural selection is not the mechanism by which differences in species are created. It is only the method by which (according to Darwinists) differences that are already there are “selected.” In short, natural selection requires something else to provide the changes in a species in order for the selection process of the species most adapted to the environment to occur.
So what causes the differences in species? Not superficial differences, but the actual changes that alter a species? The answer, according to Darwinists, is mutation.
So what happens is mutations occur in the DNA of an organism–specifically within the reproductive cells, as opposed to the body cells (e.g. a person who gets skin cancer from standing in the sun too long would not pass that on to his/her children because the reproductive cells are not affected). These mutations result in children who are different from the parent species in some manner. Leaving aside the question of whether or not mutations are ever beneficial in the first place, it is only at this point that natural selection could take over for the Darwinist.
As such, natural selection plays no role whatsoever in creating new variation within species. Mutation does that work.
And this brings us to the probability issue. Darwinists such as Richard Dawkins are more than happy to point out the obvious–that evolving from a simple cell to a complex organism in one leap is improbable to the point of being impossible. Darwinists therefore break up the method into several “small steps.” Each step is simple enough to become possible.
But when we apply this to a real-world concept, we see that breaking up probability in this sense doesn’t help the gradualist. To demonstrate that, we must first look at probability in general. In my previous linked article, I mentioned the way probability works in flipping a coin. There, we only have two options: heads or tails. DNA and possible mutations of it, however, are infinitely more complex than a simple coin toss. So, to illustrate that slightly better, imagine a 20-sided dice (such as you would find in an RPG game).
Suppose that you want to roll a sequence of numbers–say the integers from 1 to 20 in order. What are the odds of that happening? Since each step has a 1/20 chance, the odds for the total sequence are 1/(2020), or 1/104,857,600,000,000,000,000,000,000. In short, if you were to toss the dice 1,000 times per second, it would still take you longer than the age of 100,000 universes (given the current idea that the universe is between 15-17 billion years old). Thus, rolling this sequence is for all intents and purposes impossible.
If a 20-sided dice is that improbable, how much more so gradualistic evolution? How do Darwinists get around this?
Simple. While the odds of the entire sequence is that improbable, each individual step in the sequence has only a probability of 1/20. That is, when you roll the dice the first time, you have a 1/20 chance of it landing on 1. You can simply roll this until it comes up, at which point you “lock” the integer into the sequence. Now, you simply procede to the next step and roll until you get the number 2. Again, you’ll have a 1/20 chance for that. Once it comes up, you lock it in place too, and repeat.
Seen in this way, the odds of this sequence occuring become the sums of the probabilities instead of the products, or 1/400.
1/400 is not so improbable as 1/104,857,600,000,000,000,000,000,000. Therefore, the evolutionist claim, the series of steps is not so improbable after all, and gradualistic evolution could be possible.
Naturally, there are problems with this, the most glaring of which is the fact that the sequence must know that it should “lock” the integer in place when it rolls the correct one. This requires some kind of outside intelligence guiding the process; something that can in no way be considered “natural” or internal to the system of the rolling dice in the first place.
Secondly, when we consider once again the method of evolution we see that it does not allow this sort of thing to occur. Remember, we started out by showing that natural selection is divorced from mutation. Natural selection, even if working constantly, cannot create a new species until after the mutation has occured. That random mutation must be beneficial to the species in order for the mutation to be spread to many offspring, etc.
But herein lies the problem. Natural selection has no bearing on determining whether or not a specific mutation will occur. The mutation has to occur before the natural selection can work on it. Natural selection, therefore, has no bearing whatsoever on the odds of whether or not a specific mutation will occur.
Think of it this way: the odds of whether a light sensitive cell will randomly mutate do not change simply because a cell is placed in a lighted environment. The odds of the mutation remain the odds of the mutation regardless. It is only after the mutation has already occured that “nature” can then “decide” whether it was a beneficial mutation or not. It is just as likely that an organism will mutate away from a specific course than toward a specific course; indeed, it is more likely that this will be the case!
Again, consider the odds we’ve just looked at with the dice. For every 1 positive “mutation” we have 19 failures. This isn’t such a bad thing in the roll of a dice, but for a species it’s fatal! Having a mutation that does not go toward something better means that there is no survivability advantage granted to the species. Natural selection will select against these organisms.
This demonstrates that either “random” evolution is intelligently directed, or evolution can never be anything more than an ad hoc explanation after the fact. It can never be predictive because we cannot predict what the next number in the sequence will or should be (or, biologically, we can never predict what mutation will specifically occur, or whether or not it will be beneficial–not just in our environment today but for future environments that depend on the sequence being correctly established right now). Ultimately, gradualistic evolution can never be scientific because it is either a “just so” story or else it requires external intelligence to make it work.
December 22nd, 2006 at 10:57 am
Calvindude,
You’re way mistaken in your understanding of the probability space here.
First, you are assuming that there is only one beneficial specification of twenty rolls of a die — 1..20 — and that all the other combinations are deleterious or neutral. But as you say, since natural selection is a post facto filter, there’s no way to determine whether a mutation is beneficial until time takes its course. The vast majority of mutations are deleterious, and a huge number are lethal to the organism’s viability immediately — they don’t even survive the embryo, in other words.
But to make your scenario fit with the evolutionary model, you’d have to tell us who many other combinations were similarly beneficial. Perhaps rolling 20 “1s” in a row is a different, but beneficial implementation of light sensitivity in a patch of cells. The disabling flaw in your argument, then, is the premise that only one combo satisfies the demands of the environment. That’s not at all how evolutionary theory understands the process.
Furthermore, *any* combination you end up with after 20 rolls of the die is exactly as improbable as the “1..20″ sequence. This the error of post-specification in terms of arguing your probabilities. If you can state *beforehand* which sequences will be beneficial, and which won’t, then you can legitimately address the question of probabilities, and whatever incredulity you want to attach to it.
Lastly, dismissing evolution as unscientific because it incorporates stochastic processes is laughable. Statistical mechanics is predicated on stochastic processes, every bit as unpredictable as mutations. But there’s a reason why it’s called “statistical” mechanics; random processes in sizeable ensembles *do* provide predictability and testability.
Same goes for quantum mechanics. Fundamentally unpredictable and random at the lowest level, highly predictable across a statistically significant ensemble. Evolution trades on the same idea; the occurrence of a random mutation is, well, random. That’s why it’s called “random”. But across a large number of samples in a phase space, it behaves in predictable and testable ways. Indeed the whole of physics might be fairly characterized as unpredictability at the lowest level giving rise to order, symmetry and predictability at larger scales.
If you’re intent on dismissing evolution for the reasons you state, you’d have to dismiss a huge portion of all the hard sciences, as well. If you doubt this, ask yourself how you might demand that science should predict when the next alpha particle will let loose from radioactive isotope. If you can’t predict this, how can physics be maintained with respect to half-lives and radioactive decay?
-Touchstone
December 22nd, 2006 at 7:38 pm
Touchstone said:
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First, you are assuming that there is only one beneficial specification of twenty rolls of a die — 1..20 — and that all the other combinations are deleterious or neutral. But as you say, since natural selection is a post facto filter, there’s no way to determine whether a mutation is beneficial until time takes its course.
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You miss the point completely, Touchstone. The mutations are those that are specifically geared toward a goal–which is what my point has been. In other words, for the roll of the die we are looking at the odds of a specific encounter occuring (namely, all the integers 1 to 20). In evolution, we are looking at the evolution of a specific thing, such as vision.
What good is it if an organism evolves a photosensitive spot, and then in the next spot develops the beginnings of, say, an arm? These kinds of mutations get the organism no further down the chain toward vision. As such, mutations like these cannot be “counted” as moving an organism toward the ultimate goal of vision.
Since gradualistic evolution is attempting to explain how a certain thing occured, it is forced to move toward goal oriented language. However, the problem for the evolutionist is that the series itself doesn’t know the goal! It takes an outside influence that knows the goal to make the series fit the goal. Otherwise, step-wise evolution doesn’t work.
Touchstone said:
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But to make your scenario fit with the evolutionary model, you’d have to tell us who many other combinations were similarly beneficial. Perhaps rolling 20 “1s†in a row is a different, but beneficial implementation of light sensitivity in a patch of cells. The disabling flaw in your argument, then, is the premise that only one combo satisfies the demands of the environment. That’s not at all how evolutionary theory understands the process.
—
Yes, I suppose you’re right. I suppose when Dawkins speaks of breaking up the steps needed to evolve an eye, he really doesn’t mean that. He really means that you break it up and it evolves an eye here and there, and something else over there, and another thing over there, all of which will magically at some point get back to making the eye once more. I suppose that this method of step-wise evolution isn’t intended to actually demonstrate how something actually evolved to be the way it is…
Again, the only thing you’ve missed is everything.
If you are explaining how X came from Y, it does you no good to speak about how A is related to B unless that has any relation at all to the X-Y relationship. In short, if you’re explaining how a person could walk from Boston to Los Angeles in a stepwise fashion, it does you no good to say that the man combed his hair and found that was beneficial to looking good. So what? That doesn’t enable him to get from Boston to Los Angeles any faster.
Likewise, if a cell mutates some other benificial aspect that is not in the chain of events for making an eye, then that step is not beneficial to the chain that creates the eye. Thus, that step is not explanatory for the evolution of the eye. This “roll” of the dice does count against the explanatory power of the sequence.
Touchstone said:
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Furthermore, *any* combination you end up with after 20 rolls of the die is exactly as improbable as the “1..20″ sequence. This the error of post-specification in terms of arguing your probabilities.
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A) You are correct in saying that any combination is equally improbable.
B) You are incorrect in thinking that this shows a problem with my method. What this does is show a problem with the gradualistic Darwinist who would seek to use this method to lower the improbability of evolution.
C) You forget that evolution is explaining something that has occured; thus it is interested in a specific course. Why is it that we have eyes instead of no eyes? As soon as the question is defined, one is no longer looking at just “any” old toss of the dice (so to speak); one is looking at the odds of one specific roll.
Touchstone said:
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But across a large number of samples in a phase space, it behaves in predictable and testable ways.
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I daresay that if you could actually predict and test this, you would be the most famous scientist on Earth. What you are doing here is merely asserting a pipe dream. Fundamentally, it’s because you don’t seem to grasp how “random” things work (as demonstrated below).
Touchstone said:
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If you’re intent on dismissing evolution for the reasons you state, you’d have to dismiss a huge portion of all the hard sciences, as well. If you doubt this, ask yourself how you might demand that science should predict when the next alpha particle will let loose from radioactive isotope. If you can’t predict this, how can physics be maintained with respect to half-lives and radioactive decay?
—
A) It is impossible to predict “when the next alpha particle will let loose from [a] radioactive isotope.” That’s the whole point! No one can predict it! That’s why they use radioactive particles to come up with encryptions; because it’s purely random and thus no one can predict exactly when any alpha particle will release.
B) I’m not at all convinced that the physics involved with respect to half-lives and radioactive decay are as button-downed as quantum physists would like to believe; but even if they are, they are so despite not knowing when any particular alpha particle will go.
To put it back in the illustration, if you roll a dice, you know that eventually you will roll a 1. This will occur (in my 20-sided dice illustration) approximately 1/20 times. Yet you cannot predict which number will show up when you roll the dice right now. You cannot say, “It will land on 1 because the last 19 times have not been on 1.” It doesn’t work that way. But you can say that statistically, over time, it will tend toward 1/20. Thus, you can determine the “half-life” of how long it would take to roll a billion 1s without knowing when any specific 1 will be rolled.
Of course, none of this helps you in doing anything regarding evolution. Predicting the occurance of a half-life of a radioactive substance is a far more stable thing than predicting when a mutation will happen.
For instance, we know the rate of radioactive decay because we know that the radioactive substance will always be radioactive. But an organism will not always be in environments to create mutations. Furthermore, an organism will not always be in the position to pass on those mutations that do occur (suppose, for instance, a 90 year old man gets too close to a microwave and he has a mutation in his sperm–he’s not going to have children, so the mutation doesn’t matter).
So, if you want to go this route, it will be encumbant upon you to demonstrate the rate of mutations, the rate at which these will actually be beneficial in any manner, and ultimately you must provide a step-wise example of how it actually did occur to form an eye (for example) rather than just saying “It coulda happened that way.”