Taz
Your OP got me thinking about another aspect of gradual accumulation you mentioned.
The creationist would argue that something like the eye would have required all the necessary components to assemble at the same time in order for the eye to exist. Both cases show a gross ignorance of the power of accumulation.
This, of course, refers to the popular "irreducible complexity" argument of which we're all so fond. Anyway, this example has perhaps been used before, but your examples of John Doe got me thinking of our current society as an example of something that has gradually accumulated, yet exhibits some aspects of being irreducibly complex.
Por ejemplo, just 20 years ago, it was difficult to find anyone that had their own email address. Yet now, if you could some how shut down the entire internet without affecting other aspects of society, things would get chaotic pretty damn quickly. The internet has become something that is necessary for the stability of our economy (not that it's very stable right now) and our society in general. But, just because it is necessary now, doesn't mean it was always so.
The power of gradual accumulation is not just that massive changes can occur over a series of many small steps (grand canyon, walking across the country) but that as changes accumulate it can change the very nature of the system so that removing an accumulated trait does not simply revert it to what it was before.
We have many intuitions in our life and the point is that many of these intuitions are wrong. The question is, are we going to test those intuitions?
-Dan Ariely