How Selection On Behavior Shapes Brain Investment Essay

830 Words Nov 8th, 2014 4 Pages
Understanding how selection on behavior shapes brain investment is a major question in the analysis of the evolution of animal sociality [Szathmary and Maynard Smith, 1995; Edelman and Changeux, 2001; Ricklefs, 2004; Gronenberg and Riveros, 2009]. Neural tissue is energetically expensive and therefore brain regions should only enlarge when needed to meet functional demands [Niven and Laughlin, 2008]. The social brain hypothesis posits that social interactions are so cognitively demanding that social environment selects for enhanced neural development [Humphrey, 1976; Dunbar and Shultz, 2007]. Studies supporting the social brain hypothesis usually rely on comparative analyses across taxa with varying levels of social complexity and use statistical corrections for phylogenetic effects [Dunbar and Shultz, 2007]. This is problematic since comparing social behavior across taxa and social systems lack uniform metrics for social experience [Byrne and Bates, 2007; Healy and Rowe, 2007]. Studies on intraspecific variation in brain size due to social complexity are most informative to understand the relative roles of social experience and other cognitive challenges, such as foraging, on brain development [Molina and O’Donnell, 2007, 2008; Smith et al., 2010].
The evolution of complex brain structures (e.g., mushroom bodies with separate regions devoted to visual and antennal processing) predated the origin of sociality in Hymenoptera but may facilitate or provide a necessary…

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