Orbital evolution of the Kalliope family. Proper semi-major axis, a_p, vs. proper eccentricity, e_p (bottom) as well as proper inclination, sin I_p, are plotted in the course of time: initial conditions (left), 200 Myr (middle), and 1 Gyr (right). Colours and symbols correspond to the actual diameters. The observed family is plotted for comparison (green). The number of synthetic bodies is ten times larger (3020 vs. 302) to improve the statistics. Evolution is driven by the Yarkovsky effect and mean-motion resonances, especially 12:5 and 4–1–1; (22) Kalliope (yellow) is affected by the latter.