By comparing models of the Earth's mantle obtained from seismic tomography with the predictions of convective flow calculations we may interpret the seismic results in terms of mantle flow scenarios. The results of such comparisons are consistent with a picture of convective flow in the Earth's mantle in which whole mantle style flow is dominant at present but in which phase transition induced localized layering also exists. In addition, direct examination of the tomographic images show regions where the boundary between upper and lower mantle marks a significant discontinuity in heterogeneity while in other regions heterogeneities appear to be continuous across it.