Actually, I made the mistake of formulating that last response, while at work, just before a pile of things to do were given to me. So, that response got awkwardly cut off, in the middle. I hope not to do that, again. But, I shall attempt to make up for it, by moving my original point forward a bit.
No, it doesn't help one iota because it's so general as to be meaningless.
...
Simply asserting that all kinds of wonderful things can happen in nearly four billion years doesn't prove a thing.
The gist of my last post was to reduce the complications needed to evolve. We may look at humans as refined, complicated structures. But, all that is necessary for natural selection to work off of, is the DNA inside a single cell or two, at a time.
If random mutations and natural selection brought us to where we are today, why hasn't anyone been able to develop a coherent model explaining even a small portion of the progression?
They did! It's called cumulative probability. And, again, I'm sorry if my last post didn't get to the part that made that clear.
So, here is Part II:
One more point to get across, before we move into the Framework. (This is important, so pay attention):
Natural Selection is blind. It never plans ahead. The creationists who argue the "single direction" are missing the point:
Life did not have to end up the way it did! Life forms ended up the way they did as a consequence of selection pressures. Humans could easily have looked completely different, if the environment our ancestors were in was slightly different.
So an over-simplified example of the cumulative probability framework might work something like this:
Animal A and B have three offspring: C, D, and E. C has slightly more fur, D slightly less fur, and E has about the average amount of fur, in between. However, E is slightly less aggressive when finding mates.
If the environment happens to get a little cooler, C is likely to survive better than its siblings. If it gets warmer, D would probably survive better. But, if both C and D are eaten by a predator, E will have less competition in the breeding arena, and its genes will likely survive.
We might not be able to see ahead which one will make it. But, if we leap forward into the future, under a few scenarios, we can see how those small changes can be magnified:
Let's say we look at that species 100 years into the future: If their environment got gradually colder, the whole time, we would not only see more fur, but perhaps different colored and structured fur, as well.
If the environment kept getting warmer, we would see fur dissipate, and the animal's behavior might be different as well: Perhaps it swims more often to stay cool on broiling hot days, even though their ancient cousins never swam at all.
Both of those could also be the case if E survived, but: the mating preferences would be transformed: Instead of those animals adapting war-like methods to compete for mates, complete with "weapon" adaptations, mating would be more peaceful; "Weaponized" members would be selected out.
So, the bottom line, in that simple scenario, is that there are at least three paths (not "one" as the creationists claim) that the animal could have gone, depending on how the environment changed. A and B were only slightly different from C, D, and E. However, far into the future, the species would look and act very, very different, based on which of the three survived.
Of course, it is also possible that more than one of them could have survived, lived in different environments, and given enough time, would fork into different species.
This applies to humans, as well. Evolution is not a ladder. There is no reason we evolved the way we did, except for how the selection pressures worked out, in each environment our ancestors found themselves in. If the environment was slightly different at any stage, those differences would cause the selection pressures to work out differently, and those differences would be magnified, and we would look very different as a result.
Only our ego and arrogance makes us humans believe that there is only one possible way we could have become humans.
Are we getting the picture, yet?
From a mathematical perspective: C, D, and E were relatively probable mutations of their parents, A and B. If we look 100 years in the future: X, Y, and Z would be very improbable mutations of A and B. But, each generation between AB and XYZ, had mutations that were quite probable from their own parents. Selection pressures are what drove the animal to transform in any particular direction, over time.
In Part III, I will offer some real life examples, from the field. I do not have time to write them in, right now.
That may be a while . . .
Sometimes it does. Simple scientific ideas are often non-intuitive, and require a little patience to see their power.
Again, I look forward to that.
From page 121 of
The God Delusion:
What is it that makes natural selection succeed as a solution to the problem of improbability, where chance and design both fail at the starting gate? The answer is that natural selection is a cumulative process, which breaks the problem of improbability up into small pieces. Each of the small pieces is slightly improbable, but not prohibitively so.
The creationist completely misses the point because he... insists on treating the genesis of statistical improbability as a single, one-off event. He doesn't understand the power of accumulation.
Dawkins also uses a safe cracker as an analogy. The likelihood of a safe cracker hitting the right combination on a bank safe, using only a couple of random numbers, is usually very low. But, on page 122, Dawkins states:
Imagine a badly designed combination lock that gave out little hints progressively – the equivalent of the 'getting warmer' of children playing Hunt the Slipper. Suppose that when each one of the dials approaches its correct setting, the vault door opens another chink, and a dribble of money trickles out. The burglar would home in on the jackpot in no time.
The quotes are admittedly redundant to other posts in this thread, but at least it shows he did not abandon the argument.