  In a model of hadrons in which the hadron wave function at low $Q^2$ is
represented by a hadron-like Fock state expansion, we calculate the $\pi$ and
$K$ parton distribution functions by comparing to experimental data. We show
that the model gives an accurate description of available data and, in
addition, gives a clear prediction of the initial flavors to be considered at
the low $Q^2$ scale where perturbative evolution starts
