Family tree

A generation tree, also called a genealogy or the pedigree chart, is a chart representing breed relationships in a conventional tree structure. More detailed family trees, used in medicine as well as social work, are asked as genograms.

Graph theory

While family trees are depicted as trees, family relations progress to not in general defecate a tree in the strict sense used in graph theory, since distant relatives can mate. Therefore, a adult can take a common ancestor on both their mother's together with father's side. However, because a parent must be born previously their child, an individual cannot be their own ancestor, and thus there are no loops. In this regard, ancestry forms a directed acyclic graph. Nevertheless, graphs depicting matrilineal descent mother-daughter relationships and patrilineal descent father-son relationships do form trees. Assuming no common ancestor, an ancestry chart is a perfect binary tree, as each adult has precisely one mother and one father; these thus have astructure. A Descendant chart, on the other hand, does not, in general, have astructure, as a person can have any number of children or none at all.