I'm sorry, I don't understand what this means and so I don't understand why it is plausible. What are "sensory gradient-triggered impulses in simpler creatures' proto-minds"? I understand the words on their own but put together they say nothing I can make sense of.
>> Similarly, its not a stretch to see art as built from earlier attempts at representation in physical space - starting with mundane attempts at information exchange by colony insects or pack creatures.
How does that work? We're not descended from insects.
Moreover, I understand all of the above to be speculation, not something there's any kind of concrete evidence for. If you say there are no novel ideas, only combinations, we can all agree what you mean because we know what it means to take the combinations of the elements of a set. You should make your argument at least as concrete and straight-forward if you want it to move beyond the realm of imagination. Fantasizing is great, but it doesn't alone help us understand what is really going on in the real world. You also need to base your fantasies on concrete reality.