Ancestor

An ancestor is any person from whom an individual is descended in a direct line — parents, grandparents, great-grandparents, and all generations before them. The term excludes relatives such as siblings, aunts, uncles, and cousins, who are related but not in a direct line of descent.

Genealogical research focuses largely on tracing ancestors to build a complete picture of a family’s history. Each generation typically doubles the number of ancestors: 2 parents, 4 grandparents, 8 great-grandparents, and so on (in theory — in practice, pedigree collapse occurs when the same ancestor appears on multiple branches).