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Hum Nat (2012) 23:4567
DOI 10.1007/s12110-012-9130-3
Published online: 1 March 2012# Springer Science+Business Media, LLC 2012
Abstract Sexual size dimorphism is generally associated with sexual selection via agonistic male competition in nonhuman primates. These primate models play an important role in understanding the origins and evolution of human behavior. Human size dimorphism is often hypothesized to be associated with high rates of male violence and polygyny. This raises the question of whether human dimorphism and patterns of male violence are inherited from a common ancestor with chimpanzees or are uniquely derived. Here I review patterns of, and causal models for, dimorphism in humans and other primates. While dimorphism in primates is associated with agonistic male mate competition, a variety of factors can affect male and female size, and thereby dimorphism. The causes of human sexual size dimorphism are uncertain, and could involve several non-mutually-exclusive mechanisms, such as mate competition, resource competition, intergroup violence, and female choice. A phylogenetic reconstruction of the evolution of dimorphism, including fossil hominins, indicates that the modern human condition is derived. This suggests that at least some behavioral similarities with Pan associated with dimorphism may have arisen independently, and not directly from a common ancestor.
Keywords Sexual dimorphism . Hominins . Human aggression . Sexual selection . Mate competition
Sexual dimorphism is pervasive among anthropoid primates. Its evolution is associated with intrasexual agonistic aggression, usually in the form of male-male competition for access to mates. Similarly, male aggression and violence in humans has been linked to sexual selection and sexual dimorphism in body size and other secondary sexual traits, particularly using nonhuman primates as a model (Dixson 2009; Puts 2010; Sefcek et al. 2006). The closest living relatives of humanschimpanzeesshow patterns of
J. M. Plavcan (*)
Department of Anthroplogy, University of Arkansas, 330 Old Main, Fayetteville, AR 72701, USA e-mail: [email protected]
Sexual Size Dimorphism, Canine Dimorphism, and Male-Male Competition in Primates
Where Do Humans Fit In?
J. Michael Plavcan
46 Hum Nat (2012) 23:4567
intragroup and intergroup aggressive behavior that often serve as a model for humans (e.g., Lovejoy 1981, 2009; Moore 1996; Susman 1987; Tanner 1987; Wrangham 1987; Wrangham et al. 1999; Zihlman 1996). A natural question arising from comparisons of chimpanzees and humans is whether similarities in patterns of...