Dawguard said:
Most of the arguments against evolution stem from the evolution of species, not the universe. They claim that the odds of random DNA change result in a positive result, and having that change stay in place through generations, is astronomical. To have enough of these mutations to change a species for the better is, while in theory possible, is to hopelessly impossible to ever have credibility. They say, think about the complexity of an eye, or the brain. Think about everything that makes them what they are, the countless connecting pathways and mechanics, makign them all work together properly. The brain itself, which we truly have very little knowledge about, is so complex we might take several tens of thousand of years to fully understand it. How can this have happened because of a mistake, an accident?
I think you have brought up one of the main arguments of ID'ers that, in my opinion, has not been sufficiently addressed by biologists and statisticians to the general public. Many are highly persuaded (or seduced) by such an argument. I think there is a major lack of "order of magnitude" undertanding among many where simply a handwaving argument is sufficient to convince someone that so-and-so is "highly unlikely".
There are several ways to address this, and since this is still in the physics section of the forum, we will stick with either physical arguments, or use our physics expertise in tackling a problem.
1. How "unlikely" is the evolution into our present form? I have seen several estimates (and they ARE estimates in the roughest sense) of the chances of DNA's forming into its current form. Sure, the probability is very small. However, would anyone like to look at the probability of finding the top quark at the Tevatron several years ago? Let's see, they found... what, 8 events out of how many gazillion, gazillion events? And this is not counting those that are vetoed outright. Particle collider experiments are the MOST demanding scenario in terms of data acquisition, storage, and processing speed because of the mind-boggling quantity of data being gathered in just a fraction of a second. Someone should show these ID'ers the probability of finding a "positive" event out of all of these gazillion interactions and COMPARE that number with the numbers they're putting out for the DNA formation. Why this hasn't been done, I don't have a clue.
The main point here is that just because the probability "order of magnitude" appears to be miniscule doesn't mean we have not seen such occurence already, even within our lifetime. When the probability for something to occur is small, but there are a gazillion candidates, the phase space for that to occur is still reasonable enough that it CAN (and has) happened.
2. Often, the calculation of such probability itself is highly dubious. It assume that one starts off already knowing the final phase space that one has to end up with. Let me give an example. Let's say I start off with 4 letters, A,B,C, and D. I have 10 slots to fill this letters with (repetition is allowed). I want to know what is the probability that, after a random selection, I end up with a sequence that such as
BBDBDAEDDA
One can do the straightforward calculation there. One can accurately argue that the phase space (or probability) of getting such a sequence is small. However, is this really what is going on with the evolution process? I would make a definite claim that it isn't.
First of all, the formation of our DNA doesn't not happen all at once at the beginning of the evolutionary process. Natural selection dictates that
based on the external ecological pressures, there will be traits that will be more favorable than others. Now unless I slept through reading the formation of our universe and earth, the Earth a LONG TIME ago is not the same Earth that's here today. There is just a different ecological pressures when it is mainly water/molten rocks/etc. Our current forms are just not "favorable" back then!
As the environment changed, so does the external pressures, and different traits became more favorable. In other words, the DNA selection changes gradually. So maybe, using my example above, you have filled only the first 5 sequence of BBDBD_____. Now, the probability phase space to end up with BBDBDAEDDA is no longer as large as in the beginning. You have already established the first 5. It's like flipping a coin 4 times and asking for the probability that you end up with 4 heads. While the probability at the start is of course (1/2)^4, if you have already obtained 3 heads, then the probability of getting all 4 heads is just 1/2.
For some reason, I haven't seen this argument put forth convincingly to people who are being seduced into believing in this probability game.
3. There is also the major assumption that ending up with BBDBDAEDDA sequence is the ONLY possible option. I mean, at the very beginning of the selection, how do we know that BBDBDAEDDA is the ONLY sequence that would produce anything worthwhile? Now, if we question that, then let's play this game... Let's say I end up with ABACCAEDBB. There! I just got a sequence! Now, if we look at it AFTER THE FACT, someone can say
"WHOA! The probability of getting that sequence is VERY low. How'd you managed that?"
I can just walk around and say "Oh, I'm very good at this" or "Well, I'm just a very lucky person".
Yet, I didn't plan on getting that sequence. It just came up randomly. Obviously, someone who looks at it AFTER the fact, thinks I'm very lucky because it is VERY highly unlikely to get that sequence. In fact, ABACCAEDBB could be a new creature capable of producing anti-graviational effects via zero-point fluctuations! Remember, evolution never had a "final design" in mind. It is simply a trait being selected at that given moment due to all the external pressures and the available nitches in the ecology. So the sequence could easily be something else if our Earth made a right instead of a left turn at Albuquerque.
Er... Oy, this has gotten longer than expected. No one would read something this long anyway...
Zz.