Ila Fiete at The Transmitter:
Picture a box of cake mix and then imagine the fluffy, fragrant cake on your plate. Everything about the cake was already, in some sense, “in the box,” yet nowhere in the box will you find the crumb or the aroma of the cake. These qualities emerge only after you add water, turn on the oven and wait. Gradually, proteins open up and tangle, starches dissolve and gel, gas bubbles expand, and Maillard reactions begin. None of these processes are printed on the box, yet their unfolding transforms a set of simpler components into the rich macro-structure of cake.
I have come to think this is the right way to think about the developing brain. Genes specify ingredients and a short list of directions, outlining which things to combine, in what quantity and when. They don’t specify the border between the secondary visual cortex and its neighbor, or the wiring between each pair of neurons, or the precise size of the cortical sheet in each individual’s brain. Instead, these quantities emerge through the playing out of simpler processes that can lead to the self-organization of complex structures.
This is an old idea.
More here.