Research Repository

Interspecific variation in relative brain size is not correlated with intensity of sexual selection in waterfowl (Anseriformes)

Guay, Patrick-Jean and Iwaniuk, A (2008) Interspecific variation in relative brain size is not correlated with intensity of sexual selection in waterfowl (Anseriformes). Australian Journal of Zoology, 56 (5). pp. 311-321. ISSN 0004-959X

Full text for this resource is not available from the Research Repository.

Abstract

The role of sexual selection in shaping the brain is poorly understood. Although numerous studies have investigated the role of natural selection, relatively few have focussed on the role of sexual selection. Two important factors influencing the intensity of sexual selection are sperm competition and pair bonding and three different hypotheses have been proposed to explain how they could influence relative brain size. (1) The ‘extra-pair mating’ hypothesis predicts that sexual dimorphism in brain size will increase with sperm competition intensity. (2) The ‘Machiavellian intelligence’ hypothesis predicts that brain size will be larger in species with intense sperm competition. (3) The ‘relationship intelligence’ hypothesis predicts that species forming long-term pair bonds will have larger brains. We investigated sexual dimorphism in brain size and tested these three hypotheses in waterfowl by studying correlations between relative brain volume and three measures of sperm competition (testicular mass, phallus length and mating strategy) and pair-bond duration using the modern phylogenetic comparative approach.Wefound no evidence of sexual dimorphism in brain size in waterfowl after controlling for body mass and found no support for any of the three hypotheses. This suggests that brain size may not be sexually selected in waterfowl, despite evidence of sexual selection pressures on other morphological characters.

Item Type: Article
Uncontrolled Keywords: ResPubID17173, sexual selection, sperm competition, pair bonding, brain size
Subjects: FOR Classification > 0604 Genetics
FOR Classification > 0608 Zoology
Faculty/School/Research Centre/Department > Institute for Sustainability and Innovation (ISI)
Related URLs:
Depositing User: VUIR
Date Deposited: 29 Sep 2011 23:46
Last Modified: 29 Sep 2011 23:46
URI: http://vuir.vu.edu.au/id/eprint/3691
DOI: 10.1071/ZO08082
ePrint Statistics: View download statistics for this item
Citations in Scopus: 5 - View on Scopus

Repository staff only

View Item View Item

Search Google Scholar