Illustrative example of evolution of a group of magnetic features over six time steps. All magnetic features in this frame have the same polarity. Features involved in merging and splitting events are indicated by filled colored contours. The arrows in the first two panels refer to a particular event involving simultaneous splitting and merging, as discussed in the main text. The dashed arrows indicate the merging event while solid line arrows mark the splitting event. The features that are involved in this event in the first two panels are colored blue and green. The features that do not split or merge in the plotted frame are shaded gray. The order of time steps proceeds row by row, and from left to right in each row.