I think we agree entirely but are using slightly different language. I take your point that the cultural exoskeleton, including institutional structures, are part of an overall human supra-organism, while what I have been calling the supra-organism are only the soft, perishable parts. It's my mistake to call only the soft-parts a supra-organism -- as if I were calling only our bodies' soft tissues our organism and not including our skeletons and teeth.

I do want to repeat a point I have made about the exoskeleton parts. Just as only our skeletons and teeth survive our bodily deaths for very long, cultural exoskeletons -- buildings, tools, and writings in languages that have no living writers -- can survive long after all of the people who once created and operated those exoskeletons have died.

Interestingly also, people such as archaeologists who examine those buildings, tools, and writings, can create new cultures of their own that revivify those exoskeletons in new ways, as Egyptologists, tour guides and tourists have been doing for a few centuries.

Thanks again for your detailed reply.