 It is possible to see special cases, giving rise to distinct species of weak emergence, within the broad framework of non-linear dynamics. Rueger (2000) and McGivern and Rueger (2010) suggest that a form of diachronic (or evolutionary) emergence occurs when there is a sharp change in the behavior of a single system—behavior which is “qualitatively novel” with respect to its earlier behavior—as a result of a comparatively small perturbation in one of its underlying control parameters. There are well-documented cases of such transitional changes in a system’s behavior.