Development and social dominance among group‐living primates

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Abstract
Organisms are integrated systems whose physical and behavioral components codevelop and coevolve. Ontogenetic requirements in one domain are satisfied in part by prior or concurrent developments in another. This work explores how characteristic growth patterns in two primate groups interact with ecological, social, and other life-history constraints to promote the development of particular systems of agonistic relationship. First, the markedly size-dimorphic savanna baboons are contrasted with relatively nondimorphic macaques, where the pubertal growth capacity of males, relative to that of females, is comparatively modest. In baboons and other dimorphic Papionines, maturing males can be expected to invest more heavily in successful feeding competition, and known variation in the ontogeny of male-female dominance relations is well explained by this prediction. Data from five of the best-known species, for example, suggest that the female inclination to promote offspring dominaxice over male peers before puberty diminishes with increases in relative male size and growth potential at puberty. Potential mechanisms for the development of this pattern are discussed. Next, ontogenies are considered for ringtailed lemurs, a highly social, monomorphic prosimian primate in which seasonal scheduling of growth causes a large proportion of adult size to be achieved before weaning. In this species, daughters invariably develop strong alliances with their mothers, and pubertal females must overturn adults in dominance to remain in large natal groups. Despite life-history parallels between ringtails and the focal Papionines, the lemurs do not collaborate agonistically in ways that ensure matrilineal “inheritance” of dominance status, as seen in the monkeys. Body weight and individual fighting ability appear to determine dominance relations among infants, and asymmetries established before weaning typically remain stable until sexual maturation. Anatomical and behavioral data suggest that low visual acuity prevents ringtailed lemurs from developing a system of agonistic intervention that could stabilize adult dominance hierarchies and mediate rank inheritance. In any case, failure to promote the dominance of close kin is argued to have influenced life-history evolution in ringtailed lemurs extensively, including aspects of growth, reproductive biology, and social structure. These analyses identify foci for future research and illustrate the importance of bidirectional effects and feedback in the development and evolution of primate life histories and behavior.