Final answer:
A phratry consists of two or more clans with a belief in shared ancestry in a unilineal descent system. Lineages within these clans are traced through a single gender line and are guided by elders who have informal authority in their communities.
Step-by-step explanation:
A phratry is a unilineal descent group composed of two or more clans that believe they are related to each other. In societal structures that practice unilineal descent, kinship and lineage are traced through either the male or female line but not both. Such societal structures are often based on the belief that members descend from a common ancestor and are thereby linked through ancestral ties. Lineages are then clustered into clans, which are larger kinship groups that share a symbolic kinship. When these clans come together, they form a phratry.
Communities following unilineal descent are organized into lineage groups, each with elders who play a critical role in leading the community, maintaining consensus, and settling disputes. These social structures are particularly prevalent in societies that prioritize collective kinship rules and family connections, often shaped by cultural, historical, and socio-economic factors.