PedPro can automatically highlight the repeat and common ancestors in a pedigree or trial mating.
To do this, click in the Ancestor Highlight selector in the right side panel, and select either Highlight Repeat Ancestors or Highlight Common Ancestors.
A 'repeat' ancestor is one that appears at least twice within the displayed ancestors, irrespective of whether or not it appears within the sire's or dam's sides of the pedigree.
A 'common' ancestor is one that appears at least once on both sides of the pedigree i.e. in both maternal and paternal branches. Such ancestors are the source of inbreeding. A 'common' ancestor is always a 'repeat' ancestor, but not vice versa.
NOTE: The number of generations of ancestors that are used when computing inbreeding is usually larger than the number that can be displayed within the pedigree. E.g. you might have 5 generations shown in the pedigree, but use 16 when computing the inbreeding coefficient. Because of this, it is possible to have no visible common ancestors in the pedigree, yet have an inbreeding coefficient greater than zero. This happens when the nearest common ancestors lie beyond the displayed ancestors. To adjust the inbreeding calculation, including the number of ancestor generations used, select Preferences from the File menu (Mac: use the 'PedPro' application menu).