Mass loss versus semimajor axis evolution for all HL Tau simulations. The red dots are for planetesimals forming at the gap edge of the innermost planet; the blue dots are for planetesimals forming at the gap edge of the middle planet; and the yellow dots are for planetesimals forming at the gap edge of the outermost planet. Ablation is most efficient for planetesimals forming at the gap edge of the innermost planet. Ablation of CO (#8) causes planetesimals to lose mass far out in the disk. The massive planets deliver strong kicks to the planetesimals, which causes many of them to leave the simulation domain.