Patterns among systems

What patterns are there among the systems in our world?  In particular, what patterns are there between the cell as a system, the body as a system, and a society as a system?  I am concerned with patterns of adaptation: how a system learns to act adaptively in response to something that it perceives.  

Let's take the threat of environmental change as an example.  The solution to the current climate crisis will have to involve an effort that occurs on the level of (most of) humanity, not the level of the individual person.  Such a response would be an adaptive reaction taken on behalf of the system.  But at the same time, the constituent parts of this reaction (individual people) are not unaware of what they're a part of.

It would be very strange if a cell, or even the body were to operate like this.  Can we say that killer T cells understand what they're doing?  Do neurons understand what they are doing?  If they don't understand exactly what we understand them as doing, do they understand something-and what is it?