Cross-cousin marriage among the Yanomamo shows evidence of parent-offspring conflict and mate competition between brothers.

ABSTRACT: Marriage in many traditional societies often concerns the institutionalized exchange of reproductive partners among groups of kin. Such exchanges most often involve cross-cousins-marriage with the child of a parent's opposite-sex sibling-but it is unclear who benefits from these exchanges. Here we analyze the fitness consequences of marrying relatives among the Yanomamö from the Amazon. When individuals marry close kin, we find that (i) both husbands and wives have slightly lower fertility; (ii) offspring suffer from inbreeding depression; (iii) parents have more grandchildren; and (iv) siblings, especially brothers, benefit when their opposite-sex siblings marry relatives but not when their same-sex siblings do. Therefore, individuals seem to benefit when their

SUBMITTER: Chagnon NA 

PROVIDER: S-EPMC5380100 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature