title: Age at maturity in wild baboons: genetic, environmental and demographic influences.
abstract: The timing of early life-history events, such as sexual maturation and first reproduction, can greatly influence variation in individual fitness. In this study, we analysed possible sources of variation underlying different measures of age at social and physical maturation in wild baboons in the Amboseli basin, Kenya. The Amboseli baboons are a natural population primarily comprised of yellow baboons (Papio cynocephalus) that occasionally hybridize with anubis baboons (Papio anubis) from outside the basin. We found that males and females differed in the extent to which various factors influenced their maturation. Surprisingly, we found that male maturation was most strongly related to the proportion of anubis ancestry revealed by their microsatellite genotypes: hybrid males matured earlier than yellow males. In contrast, although hybrid females reached menarche slightly earlier than yellow females, maternal rank and the presence of maternal relatives had the largest effects on female maturation, followed by more modest effects of group size and rainfall. Our results indicate that a complex combination of demographic, genetic, environmental, and maternal effects contribute to variation in the timing of these life-history milestones.
authors.affiliation: Department of Biology, Duke University, PO Box 90338, Durham, NC 27708, USA. mariecharp@yahoo.fr
authors.forename: M J E
authors.initials: MJ
authors.lastname: Charpentier
authors.forename: J
authors.initials: J
authors.lastname: Tung
authors.forename: J
authors.initials: J
authors.lastname: Altmann
authors.forename: S C
authors.initials: SC
authors.lastname: Alberts
mesh_terms: D000818:Animals; D004247:DNA / Q000737:chemistry / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006824:Hybridization, Genetic; D007630:Kenya; D008297:Male; D008572:Menarche / Q000502:physiology; D018895:Microsatellite Repeats; D015999:Multivariate Analysis; D048530:Papio anubis / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D048548:Papio cynocephalus / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D011891:Rain; D012741:Sexual Maturation / Q000235:genetics / Q000502:physiology*; D012930:Social Dominance; D013737:Testis / Q000502:physiology
chemical_list: D004247:DNA