Nous aurons le plaisir d’accueillir Laura Muniz,
le jeudi 6 octobre à 14h00 (attention à cette heure inhabituelle)
Elle nous présentera ses recherches sur le thème :
"The impact of kin availability on sociality and reproductive strategies in non-human primates"
Laura Muniz est chercheuse au Max Planck Institute for Evolutionary Anthropology à Leipzig, Allemagne, et vous trouverez ci-dessous le résumé de ses travaux.
Our understanding of the evolution and maintenance of sociality is greatly influenced by kin selection theory, which posits that cooperation between individuals will be favored when the direct costs to the individuals are smaller than the indirect fitness benefits obtained.
Kin associations were described in several mammalian species and numerous studies have shown that the social structure of primate groups is largely based on kinship. In fact, female philopatric primate species are often classified as female-bonded due to the formation of life-long, stable associations between female kin, which have profound implications for the social dynamics of the groups.
Furthermore, empirical evidence shows that kin availability correlates positively with different measures of female fitness.
In contrast, little was known about the impact of kin availability on the fitness of dispersing males until recently, when the refinement of molecular techniques enabled the determination of paternity and genetic relatedness between individuals.
In this seminar I will examine the fitness outcome of male primate reproductive and migration strategies and investigate how the presence of kin affects male reproductive and social behavior.
I will present data on two primate species for which long term behavioral and demographic records were available. The white-faced capuchins (Cebus capucinus) of Lomas Barbudal, Costa Rica, are remarkable for extensive male-male cooperation in group defense, often resulting in undefined dominance hierarchies below the alpha male and extended periods of stability in group composition.
With paternity data derived from complete genotypes at 18 microsatellite markers for three social groups, I found that alpha males had almost complete monopolization of reproduction during the initial years of the alpha tenure, and that the degree of reproductive skew decreased proportionally with the number of alpha male daughters breeding in the group due to inbreeding avoidance. Because the alpha male is not always closely related to subordinate males, subordinates often invest several years in the relationship with an unrelated alpha male until they are able to breed in the group.
In contrast, rhesus monkeys (Macaca mulatta) of Cayo Santiago, Puerto Rico, exhibit a queuing strategy for attaining dominance rank and typically move alone between social groups. Group kin composition derived from pedigrees shows that males of this species co-reside with kin.
However, there is no evidence that males preferentially associate with kin, nor do they seem to derive direct fitness benefits from associating with females in their social group.
It is likely that female choice play an important role in determining reproductive success in this species.
Lieu : Salle Chevalier, bât. 135 HNS, 43 rue Cuvier Paris 5.