  We derive the non-analytic chiral behavior of the flavor asymmetry dbar -
ubar. Such behavior is a unique characteristic of Goldstone boson loops in
chiral theories, including QCD, and establishes the unambiguous role played by
the Goldstone boson cloud in the sea of the proton. Generalizing the results to
the SU(3) sector, we show that strange chiral loops require that the s - sbar
distribution be non-zero.
