  We have done simulations of lattice QCD with different numbers of light
dynamical quarks. Since we cannot reach the continuum limit with our current
computers, we have done comparisons with 0 (quenched), 2 and 4 light quark
flavors with the physical volume and lattice spacing constant, when these are
determined from the mass of the rho. We find a 7% (2 standard deviation)
difference in the nucleon to rho mass ratio for 2 and 4 quarks. More
importantly, the effects of chiral symmetry breaking are dramatically decreased
for the case of 4 light quarks.
