Gravity plays a negligible role in the flow of electric charges in a metallic wire. In metallic conductors, such as copper or aluminum wires, electric current is primarily driven by the electric field established by an applied voltage. The force due to gravity on electrons is extremely weak compared to the electric forces involved. While gravity does exert a force on electrons, the magnitude is much smaller than the forces influencing electron movement within a conductor. Therefore, the impact of gravity on the flow of electric charges in a metallic wire is essentially negligible in comparison to electric field-driven forces.