Final answer:
Ambilineal descent differs from unilineal descent (tracing lineage through one gendered line) and bilateral descent (tracing through both parent's lines) by allowing families to choose whether to trace through the mother's or father's side.
Step-by-step explanation:
When exploring types of descent systems, we can identify ambilineal descent as distinct from both unilineal and bilateral descent. Ambilineal descent allows for the tracing of an individual's lineage through either the mother's or father's side, and each family can choose which side to follow often based on opportunities at the time of marriage. This contrasts with unilineal descent, where lineage is strictly through either the father's line (patrilineal) or the mother's line (matrilineal) for all families within a society. Bilateral descent involves tracing an individual's lineage through both the mother's and father's sides, and is the most common form of descent in the United States.