Hillis considers here that intelligence might be a symbiotic phenomenon, exemplified with apes having the ability to copy, and songs starting to evolve ontop of this substrate.
He argues that it could be possible to construct a different artificial substrate which will enable the emergence of intelligence on top of it and gives some estimates of the needed computational power.
Link: http://web.archive.org/web/20010109111400/longnow.org/about/articles/ArtEden.html