Sexual Selection Predicts Brain Structure in Dragon Lizards
doi: 10.1111/jeb.12984 Sexual selection predicts brain structure in dragon lizards D.HOOPS*,J.F.P.ULLMANN†,A.L.JANKE†, M. VIDAL-GARCIA*, T. STAIT-GARDNER‡, Y. DWIHAPSARI‡,T.MERKLING*,W.S.PRICE‡, J. A. ENDLER§,M.J.WHITING¶ &J.S.KEOGH* *Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Acton, ACT, Australia †Center for Advanced Imaging, The University of Queensland, Brisbane, Qld, Australia ‡Nanoscale Organization and Dynamics Group, School of Science and Health, University of Western Sydney, Penrith, NSW, Australia §Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Vic., Australia ¶Department of Biological Sciences, Discipline of Brain, Behavior and Evolution, Macquarie University, Sydney, NSW, Australia Keywords: Abstract agamid; Phenotypic traits such as ornaments and armaments are generally shaped by lizard; sexual selection, which often favours larger and more elaborate males com- magnetic resonance imaging; pared to females. But can sexual selection also influence the brain? Previous medial preoptic nucleus; studies in vertebrates report contradictory results with no consistent pattern neuroscience; between variation in brain structure and the strength of sexual selection. reptile; We hypothesize that sexual selection will act in a consistent way on two sexual dichromatism; vertebrate brain regions that directly regulate sexual behaviour: the medial sexual dimorphism; preoptic nucleus (MPON) and the ventromedial hypothalamic nucleus ventromedial hypothalamic nucleus; (VMN). The MPON regulates male reproductive behaviour whereas the visual modelling. VMN regulates female reproductive behaviour and is also involved in male aggression. To test our hypothesis, we used high-resolution magnetic reso- nance imaging combined with traditional histology of brains in 14 dragon lizard species of the genus Ctenophorus that vary in the strength of precopu- latory sexual selection.
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