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Sexual dimorphism in the craniofacial growth of the guinea pig ( Cavia porcellus )
Author(s) -
Farmer Meredith A.,
German Rebecca Z.
Publication year - 2004
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.10180
Subject(s) - cavia , sexual dimorphism , biology , marsupial , zoology , craniofacial , ontogeny , heterochrony , evolutionary biology , phylogenetic tree , new guinea , guinea pig , genetics , history , ethnology , gene
Abstract Variation between the sexes during ontogeny is frequently overlooked in discussions of the phylogenetic patterns of adult sexual dimorphism. Different growth trajectories can produce identical degrees and direction of adult dimorphism and the possibility exists that similarities in adults may be the result of differing growth patterns, suggesting independent evolutionary pathways among species to the seemingly identical adult morphology. We quantified the sexual dimorphism in craniofacial skeletal growth of Cavia porcellus, the guinea pig, using longitudinally collected radiographs. Guinea pigs have male‐biased sexual dimorphism in size and in growth parameters, despite literature reports to the contrary. These results, analyzed with equivalent data for five species of rodents, and two outgroups representing similarly sized mammals, a rabbit and a marsupial, indicate that some aspects of sexual differences in growth follow phylogenetic lines, while others are a function of whether the species has male‐ or female‐biased dimorphism. J. Morphol. 259:172–181, 2004. © 2003 Wiley‐Liss, Inc.