  So-called 'dark comets' are small, morphologically inactive near-Earth
objects (NEOs) that exhibit nongravitational accelerations inconsistent with
radiative effects. These objects exhibit short rotational periods (minutes to
hours), where measured. We find that the strengths required to prevent
catastrophic disintegration are consistent with those measured in cometary
nuclei and expected in rubble pile objects. We hypothesize that these dark
comets are the end result of a rotational fragmentation cascade, which is
consistent with their measured physical properties. We calculate the predicted
size-frequency distribution for objects evolving under this model. Using
dynamical simulations, we further demonstrate that the majority of these bodies
originated from the $\nu_6$ resonance, implying the existence of volatiles in
the current inner main belt. Moreover, one of the dark comets, (523599) 2003
RM, likely originated from the outer main belt, although a JFC origin is also
plausible. These results provide strong evidence that volatiles from a
reservoir in the inner main belt are present in the near-Earth environment.
