The Evolutionary Genetics of Behavioural Variation: multivariate perspectives on personality in the Trinidadian guppy.
White, Stephen John
Thesis or dissertation
University of Exeter
Animal personality is found in a wide range of taxa, yet our knowledge of what maintains consistent among-individual variation in behaviour is still incomplete. Many personality traits are associated with fitness, leading to the expectation that, under selection, genetic (and among-individual) variation will be eroded over time. Several adaptive models have been developed in order to explain this maintenance of variation. These include state-dependence, state-behaviour feedback loops, life-history and behavioural coadaptation and the Pace of Life syndrome. These models represent good starting points for thinking about what drives and maintains among-individual variation in behaviour, and while empirical support for these models is mixed, one thing they do have in common is the assumption of a significant genetic basis underpinning personality traits. Significant heritability is required for an evolutionary response to selection and for among-individual variation to be adaptive. The univariate estimates of heritability for personality traits that are growing in the literature, while useful, are likely insufficient to predict how personality traits will respond to selection. This thesis uses the Trinidadian guppy, Poecilia reticulata, and other species to explore patterns of among-individual and genetic variation in personality traits, advocating the benefits of using multivariate perspectives throughout. Firstly, the among-individual covariance structure between measures of boldness, growth and metabolic rate are estimated in a test of the Pace of Life syndrome. Secondly, an appraisal of the relative strength of maternal and genetic effects on offspring personality and how it changes over ontogeny. Next, a comprehensive treatment of sexual dimorphism in behaviour and size followed by analysis of genotype-by-sex interactions using both univariate and multivariate methods. Finally, a comparative analysis of personality in 7 species of small fish, identifying the main axis of among-individual variation from a single assay in each and quantifying the phylogenetic signal.
White, S. J., T. J. Kells, and A. J. Wilson. 2016. Metabolism, personality and pace of life in the Trinidadian guppy, Poecilia reticulata. Behaviour 153:1517–1543.
PhD in Biological Sciences