RE: " for at least some of the evolutionary advantages of certain (proto) art practices to have been conferred upon their practioners required the products (proto-artworks) of those (proto) art practices to display marks of their producers"

I really don't know what "proto-art" is. I cannot recall ever having seen any, and I've seen a lot of art. Can you explain?

7M also intrigues me. It reads "A function of artworks is to display marks of the producer."

Why would this be a function of art? All kinds of things show the "marks of the producer" - a badly written essay, a break-in where the thief left his fingerprints, Mr Madoff's villainous financial scam, etc etc.

Moreover, there are vast quantities of art which carry no form of signature and whose producers are quite unknown - including very famous pieces like the Victory of Samothrace, the frescos at Ajanta, and the sculpture at Chartres. Not to mention nearly all Egyptian, African, Oceanic, and Pr-Columbian art, etc. Unless you mean that the "producers" happened to be known at the time. But even so, what valuable "function" could that circumstance have performed if the society in question judged their work inadequate and unworthy?  Presumably only that the members of said society would have known who not to ask next time!

DA