  A new class of modified gravity theories, made possible by subtle features of
the canonical formulation of general covariance, naturally allows MOND-like
behavior (MOdified Newtonian Dynamics) in effective space-time solutions
without introducing new fields. A detailed analysis reveals a relationship with
various quantum-gravity features, in particular in canonical approaches, and
shows several properties of potential observational relevance. A fundamental
origin of MOND and a corresponding solution to the dark-matter problem are
therefore possible and testable.
