  We examine the $Q^2$ evolution of gluon polarization in polarized nucleons.
As is well known, the evolution of $\alpha_s \Delta G(Q^2)$ is negligible for
typical momentum transfer variations found in experimental deep inelastic
scattering. As $\alpha_s$ increases, however, the leading nonzero term in the
evolution equation for the singlet first moment reduces the magnitude of the
gluon spin. At low $Q^2$ the term $\alpha_s \Delta G$ can vanish, and
ultimately become negative. Thus, low energy model calculations yielding
negative $\Delta G$ are not necessarily in conflict with experimental evidence
for positive gluon polarization at high $Q^2$.
