//Oh come on Mibs don't you ever communicate an original thought? Where does that come from?//
Possibly from a logical derivation based on acquired, assimilated information but just as likely from . . . 'out of the blue'.
Imagination provides a wealth of potential information but that potential is only realised through the process of understanding if and how it correlates to reality. We are not born knowing how to distinguish illusion from reality. That requires correctly interpreting and incorporating lifetimes of accumulated knowledge and wisdom, not least of which includes a rudimentary understanding of how the mind works.
mibs; //A mind deprived of any means of ever having acquired information of the external world in which it exists would be senseless . . . literally.//
I don't know if spiders have minds, but they have brains & how can they do this without ever having seen it done?
Although it appears a first glance to me to be an example of innate behavior that has evolved through millions of generations of trial and error, I should probably refer you to an ethologist for an answer to that question Khandro.
mibs; I've just read through it & I think the good Dr John Meyer is actually struggling to comprehend & interpret the facts (nothing wrong with that btw) & place them into his own view of the order of things.
He's clear on describing observed phenomena; the 'how', but a shaky on the 'why?', he's rather hide-bound by the full Darwinian agenda I think.
Those critters whose default brain state at birth didn't give the creature the basics of survival, aren't around any more. They died young. Those that do have such basics, in this case web spinning, inevitability can do so without needing to learn it (or as explained, they'd not be here).