Robbins Andrew M, Gray Maryke, Breuer Thomas, Manguette Marie, Stokes Emma J, Uwingeli Prosper, Mburanumwe Innocent, Kagoda Edwin, Robbins Martha M
Max Planck Institute for Evolutionary Anthropology , Deutscher Platz 6, 04103 Leipzig , Germany.
Formerly with the International Gorilla Conservation Programme , PO Box 931, Kigali , Rwanda.
R Soc Open Sci. 2016 Oct 19;3(10):160533. doi: 10.1098/rsos.160533. eCollection 2016 Oct.
When mothers continue to support their offspring beyond infancy, they can influence the fitness of those offspring, the strength of social relationships within their groups, and the life-history traits of their species. Using up to 30 years of demographic data from 58 groups of gorillas in two study sites, this study extends such findings by showing that mothers may also contribute to differences in social organization between closely related species. Female mountain gorillas remained with their sons for significantly longer than western gorillas, which may explain why male philopatry and multimale groups are more common among mountain gorillas. The presence of the putative father and other familiar males did not vary significantly between species, and we found only limited support for the socio-ecological theory that the distribution of adult males is influenced by the distribution of females. Within each gorilla species, variations in those distributions may also reflect the different stages in the typical life cycle of a group. Collectively, our results highlight the potentially far-reaching consequences of maternal support that extends beyond infancy, and they illustrate the opportunity to incorporate additional factors into phylogenetic analyses of variations in social organization, including studies of human evolution.
当母亲在婴儿期之后继续支持其后代时，她们会影响这些后代的健康状况、群体内社会关系的强度以及物种的生活史特征。本研究利用来自两个研究地点58组大猩猩长达30年的人口统计数据，通过表明母亲可能也导致了亲缘关系密切的物种之间社会组织的差异，扩展了此类研究结果。雌性山地大猩猩与儿子待在一起的时间明显长于西部大猩猩，这或许可以解释为何雄性留居现象和多雄性群体在山地大猩猩中更为常见。假定父亲和其他熟悉雄性的存在在不同物种之间没有显著差异，而且我们仅找到有限的证据支持社会生态理论，即成年雄性的分布受雌性分布的影响。在每个大猩猩物种内部，这些分布的差异也可能反映了群体典型生命周期中的不同阶段。总体而言，我们的研究结果凸显了婴儿期之后母亲支持可能产生的深远影响，并且说明了将其他因素纳入社会组织差异的系统发育分析的机会，包括人类进化研究。
