We have examined the behavior of the forward-to-backward ratio {ital R} of the cross section for the {sup 2}H({gamma},{ital p}){ital n} reaction. The data show a weak dependence of {ital R} on the photon energy and group around a value of 1.5 which agrees with the prediction of a simple quark model. An energy dependence of {ital R} is predicted in the quark-gluon string model and is shown to be connected to the ratio of {ital d}/{ital u} quark distributions in the proton.