The influence of phylogeny on the social behaviour of macaques (Primates: Cercopithecidae, genus Macaca)

The macaques are the most geographically widespread and behaviourally diverse primate genus. Many of the diversified features of social behaviour and organization in this genus have been attributed to socio-ecological differences. However, some core aspects of social behaviour and organization appear to be highly conservative, suggesting a high degree of phylogenetic inertia. A recently derived classification of macaque social organization, as well as a large range of social and physical traits, were analysed for 16 species to ascertain the role of phylogeny in explaining the distribution of these traits within the genus Macaca. These traits were mapped onto two alternative phylogenies. The pattern of social organization, based on the degree of asymmetry in social relations, exhibited a high and significant level of phylogenetic inertia, as did seven of the 22 individual traits compared. A profile constructed of the most likely ancestral state for this character matrix showed that it most closely resembles the pattern present in the Barbary macaque (M. sylvanus), which, based on both molecular and morphological data, most closely resembles the ancestral macaque.