Been considering this in depth recently and have an idea as "germ cell" as an ideal of a conceptualiztion tool.
For instance in Yro's moon phase paper the unit of analysis is in understanding knowledge acquisition as what the triangle of actiivy expands upon.
Brazil's recent social upheavel would expand upon human subsistance and basic needs.
The framework is in place for studying each of these activity systems (perhaps systems isn't best word and another would provide better clarity) with Yro's expanded triangle but because of the diversity of human existence the "germ cell" proposition provides a good platform for how to specify the utilization of the expanded triangle.
Thinking out loud
what do others think?
eric