Sexual dimorphism in primates
Year: 1989
Type: dissertation
Abstract: It is taken for granted in human societies that men \nare, on average, slightly taller, larger and heavier than \nwomen, despite a considerable overlap in their respective \nweight distributions. However, among mammals in general, \nintersexual size differences within a single species do \nnot always favour males and range from leopard seals, with \nthe female 20% longer and correspondingly heavier than the \nconspecific male, to gorillas with the male almost twice \nthe size of his mate. \nThere is ample evidence that body size plays a \nfundamental role in relation to an animal's survival. \nConsequently, when males and females of the same species \nattain different adult body weights, these should be seen \nin the overall context of divergent life history \nstrategies, as emphasised by the typically later \nachievement of sexual maturity in the larger bodied sex. \nMost explanations of sexual size dimorphism in \nprimates tend to be male-centred. They typically emphasize \ncompetition between males for females and protection of \nthe social group by larger bodied males. However, such \naccounts are commonly marred by circular arguments and \npost hoc rationalisations. They are also self-defeating in \ntheir neglect of the possible effects of natural selection \nacting on females. The present research examines the \nontogeny of sexual size dimorphism in terms of the \ndivergent energetic needs of males and females. \nAn allometric approach has been adopted, and the \nfrustrations of circularity overcome by exploiting the \nspecial relation which exists between brain size and body \nweight. The results indicate that, at least for simian \nprimates, body size reduction in females has played a major role in the evolution of sexual size dimorphism. For several \nspecies of larger bodied primates this difference has \napparently been enhanced by body size increase in males. The \nscaling of molar tooth area with body weight corroborates \nthese findings.
Author: Lesley Anita Willner
Language: English
Topic: Primate Behavior and Ecology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W9214777