Time evolution of the RMS of planetesimals’ eccentricity (top left), inclination (top right), and surface density (bottom left) of a circumstellar disc that also contains 10 embryos. The lines represent temporal snapshots of the three quantities, and are spaced by about 2 × 10⁵ yr. The blue line in both panels denote the initial profile. The dashed vertical lines represent the location of the embryos, which is fixed in this case. N-body interactions were also disabled. The lifetime of the gas disc is shorter than the case presented in Fig. 3 due to the accretion by the protoplanets.