> the cells in the heart muscles beat together without a central monitor A control/monitoring system isn't required to be centralised, or even different from w

> the cells in the heart muscles beat together without a central monitor A control/monitoring system isn't required to be centralised, or even different from what is controlled/monitored. E.g. with groups of fish every fish just keeps his distance to other fish, resulting in the well known global as-if-centrally-coordinated behaviour of fish groups. So I think the statement just means that there is some kind of control loop. It doesn't say how it looks.