  If an ultraviolet fixed point renders quantum gravity renormalizable, the
effective potential for a singlet scalar field -- the cosmon -- can be computed
according to the corresponding scaling solution of the renormalization group
equations. We associate the largest intrinsic mass scale generated by the flow
away from the fixed point with the scale of present dark energy density. This
results in a highly predictive scenario for the evolution of dynamical dark
energy. It solves the cosmological constant problem dynamically, and may be
called "quantum gravity quintessence". A first setting without quantum scale
symmetry violation in the neutrino sector could explain the present amount of
dark energy, but fails for the constraints on its time evolution. In contrast,
a logarithmic scale symmetry violation in the beyond standard model sector
responsible for the neutrino masses induces a non-vanishing cosmon-neutrino
coupling in the Einstein frame. This yields a cosmology similar to growing
neutrino quintessence, which could be compatible with present observation. The
small number of unknown parameters turns the scaling solution for quantum
gravity into a fundamental explanation of dynamical dark energy which can be
falsified.
