On Google+, [Ted Pavlic](https://sols.asu.edu/people/theodore-p-pavlic) wrote:

> A number of prominent control theorists (like [Richard Murray](http://www.cds.caltech.edu/~murray/wiki/Main_Page) and his most recent graduate students and postdocs) have turned to synthetic biology as a major application area. Consequently, they make heavy use of another diagram used in living systems -- the gene regulatory network. Gene regulatory networks are very similar to signal flow diagrams as they incorporate negative and positive feedback and amplification. You didn't mention gene regulatory networks, but I think you should consider them as you venture outside of control.

> At larger ecosystem scales, it is important to consider food webs and how to augment them with mass-balance constraints. To this end, researchers have developed "[ecological stoichiometry](http://en.wikipedia.org/wiki/Ecological_stoichiometry)" which turns food webs into chemical reaction networks. More recently, ES researchers in ecology have retuned it to consider the scale of the cell. This new version is being called "[biological stoichiometry](http://www.nature.com/scitable/knowledge/library/biological-stoichiometry-102248897)." Both cases seem to fit into your ultimate goal.

> I'm a control theorist working in a behavioral ecology lab -- splitting my collaborative time between engineers, physicists, mathematicians, and biologists (behavioral, neuroethological, physiological). Additionally, I periodically interact with biogeochemists interested in geological engineering that lives exactly at the technology--biosphere interface. So there are a lot of people working in this space, and it would probably be useful to survey how people are already shuttling ideas about abstraction across these disciplinary boundaries.

I'll add this comment to [[Network theory]].