David’s comment: Every cell in C. elegans is completely understood, including the 302 neurons. Plasticity in learning can be easily studied as this paper shows. Here it is easy to see a neural mechanism for intelligence and learning. My point is the single-celled organism, learns by a different mechanism and it is alterations in DNA as Shapiro has shown. It necessarily much simpler, and probably automatic once a new response is established.

Since it hasn’t got a brain, of course it must learn by a different mechanism, and I’m happy to accept that it is simpler. The question is not what happens once a new response is established, but how a new response comes about in the first place. I suggest intelligence. You suggest divine dabbling or preprogramming of every response throughout the history of life.