Abstract
Tropical rainforests support immense biodiversity through microhabitat partitioning and local adaptation. This can expose closely related species to contrasting sensory worlds despite overlapping spatial ranges. Light abundance and spectra likely vary across these environments, but it is not known whether this contributes to predictable niche segregation within wild animal communities and, if so, whether this can promote evolutionary change in the sensory system. The Neotropical radiation of mimetic butterflies provide case studies for comparing how visual information varies across small spatial scales in a terrestrial environment. By studying a diverse community of ithomiine species in eastern Ecuador, and transitions between closely related Heliconius species, I will illustrate how variation in forest structure can create ecologically relevant photic environments. Quantifying visual system variation at the perceptual and processing level across hundreds of wild-caught individuals revealed that dual patterns of divergence and convergence in light environment can drive visual evolution towards distinct optima, particularly for structures within the optic lobe, the primary visual processing centre. This work illustrates the importance of visual ecology as a significant driver of divergent neural and sensory traits in terrestrial habitats, suggesting an underappreciated role in ecological diversification and speciation.
Biography
I study the evolution of brains and behaviour. I am particularly interested in how brains adapt to different environments, how changes in brain structure produce behavioural differences, and how selection navigates developmental and functional constraints that may limit or channel the adaptive response.
I take a comparative approach to tackling these questions, comparing molecular and phenotypic data across species. Much of my work in mammals has focused on identifying genes associated with the evolution of brain size, and investigating the causes and consequences of co-evolution between different regions of the brain, and between brain and body size. I also have side interests in dwarfism, animal play, and human evolution.
Currently, Neotropical butterflies are the major focus of my research. I study two tribes of mimetic butterflies, the Ithomiini and Heliconiini. The diversification of these butterflies has often involved ecological adaptation to different habitat types and ecological niches. As a result they show a range of derived behavioural traits including sensory adaptations and novel foraging behaviours. This pattern of ecological adaptation make these butterflies an ideal case study in ecological neurobiology.