We demonstrate that sea quark effects of a magnitude expected from renormalization group considerations are clearly visible in the strong coupling constant measured in current full QCD simulations. Building on this result an estimate of αMS-(5)(MZ) (MS- denotes the modified minimal subtraction scheme) is made employing the charmonium 1S-1P mass splitting calculated on full QCD configurations generated with two flavors of dynamical Kogut-Susskind quarks to fix the scale.