reversibility of equations of motion

please compare the equation of motion in electrodynamics, \(\frac{\mathrm{d}^2x^\alpha}{\mathrm{d}\tau^2} = \frac{q}{m}F^{\alpha}_\mu\frac{\mathrm{d}x^\mu}{\mathrm{d}\tau}\) with that of general relativity, \(\frac{\mathrm{d}^2 x^\alpha}{\mathrm{d}\tau^2} = -\Gamma^\alpha_{\mu\nu}\frac{\mathrm{d} x^\mu}{\mathrm{d}\tau}\frac{\mathrm{d}x^\nu}{\mathrm{d}\tau}\) what would be your answer concerning the way in which time-reversibility is realised? doesn’t it look strange that the Lorentz-force is proportional to the 4-velocity but gravity to the squared 4-velocity, nevertheless there has to be time-reversibility in both cases?